CABA US Equity☆

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following discussion and analysis of our financial condition and results of operations together with our consolidated financial statements and related notes appearing elsewhere in this Annual Report on Form 10-K, or this Annual Report. Some of the information contained in this discussion and analysis or set forth elsewhere in this Annual Report, including information with respect to our plans and strategy for our business and related financing, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the section entitled “Risk Factors,” our actual results could differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis. You should carefully read the section entitled “Risk Factors” to gain an understanding of the important factors that could cause actual results to differ materially from our forward-looking statements. Please also see the section entitled “Special Note Regarding Forward-Looking Statements.” We do not assume any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

Overview

We are a clinical-stage biotechnology company focused on the discovery and development of innovative engineered T cell therapies that have the potential to provide deep and durable, perhaps curative, responses with one-time administration for patients with autoimmune diseases. Our proprietary CABA®, or Cabaletta Approach to B cell Ablation, platform encompasses two strategies. Our CARTA, or Chimeric Antigen Receptor T cells for Autoimmunity, approach is designed to potentially reset the immune system. Our legacy CAART, or Chimeric AutoAntibody Receptor T cells, approach is designed to engineer T cells to selectively engage and eliminate only disease-causing B cells. We believe our CABA® platform has the potential to safely enable complete and durable responses for a broad range of autoimmune diseases and that it has potential applicability across dozens of autoimmune diseases that we have identified, evaluated and prioritized.

Resecabtagene autoleucel (rese-cel, formerly referred to as CABA-201) is a 4-1BB co-stimulatory domain-containing fully human CD19-CAR T construct designed to treat patients with a broad range of autoimmune diseases and our lead product candidate within the CARTA strategy. Rese-cel is designed to achieve transient and deep depletion of all B cells following a single treatment by using T cells engineered to express an antibody fragment that recognizes a B cell receptor expressed on the surface of all B cells. The construct is designed to allow for the deep elimination of all B cells, including all B cells that contribute to disease, with subsequent repopulation by healthy naïve B cells. This approach has the potential to reset the immune system, providing meaningful durable and complete clinical responses to patients off immunosuppressive therapies.

In March 2023, the United States Food and Drug Administration, or the FDA, granted clearance of our rese-cel Investigational New Drug, or IND, application for treatment of SLE in patients with active lupus nephritis, or LN, or active SLE without renal involvement. SLE is a chronic, potentially severe, autoimmune disease, most commonly impacting young women between the ages of 15 and 40 with higher frequency and more severity in people of color, where the immune system attacks healthy tissue throughout the body. SLE affects an estimated up to 320,000 patients in the U.S., and 150,000 patients in Europe, with LN as the most common end-organ manifestation, affecting approximately 40% of SLE patients. In May 2023, we announced the FDA granted Fast Track Designation for rese-cel, designed to deplete CD19-positive B cells and improve disease activity in patients with SLE and LN. The RESET-SLETM Phase 1/2 clinical trial of rese-cel is designed to treat six SLE patients with active LN, and in a separate parallel cohort, six patients with active SLE without renal involvement, with a single weight-based dose of 1.0 x 106 cells/kg. In March 2024, Health Canada issued a No Objection Letter in response to a Clinical Trial Application, or CTA, for the RESET-SLETM trial submitted by Cabaletta, enabling us to begin the process to activate clinical trial sites and pursue patient enrollment for the RESET-SLETM trial in Canada. In October 2024, the European Medicines Agency allowed a CTA submitted by Cabaletta for the RESET-SLETM trial to proceed, enabling us to begin the process of activating clinical trial sites and pursuing patient enrollment for the RESET-SLETM trial. The trial is open for enrollment across multiple sites in the United States and one site in the European Union.

In May 2023, the FDA granted clearance of our rese-cel IND application for treatment of idiopathic inflammatory myopathies, or IIM, or myositis. Myositis refers to a group of autoimmune diseases characterized by inflammation and muscle weakness. The three myositis subtypes being evaluated in the RESET-MyositisTM Phase 1/2 clinical trial of rese-cel affect approximately 70,000 patients in the U.S. and approximately 85,000 patients in Europe and typically affect middle-aged individuals, particularly women. The RESET-MyositisTM clinical trial, which is actively enrolling patients, is designed to treat six patients with dermatomyositis, six patients with anti-synthetase syndrome, and six patients with immune-mediated necrotizing myopathy, all in separate parallel cohorts. We announced the FDA granted Fast Track Designation for rese-cel for the treatment of patients with dermatomyositis to improve disease activity and Orphan Drug Designation for rese-cel for the treatment of myositis in January and February 2024,

96

respectively. In March 2024, we announced the FDA granted Rare Pediatric Disease designation for rese-cel for juvenile dermatomyositis. The trial is open for enrollment across multiple sites in the United States and one site in the United Kingdom.

In October 2023, we announced that the FDA granted clearance of our rese-cel IND application for treatment of systemic sclerosis, or SSc. SSc is a rare and potentially fatal chronic autoimmune disease characterized by progressive skin and internal organ fibrosis that can be life-threatening, including interstitial lung disease, pulmonary hypertension, and scleroderma renal crisis. SSc affects approximately 90,000 patients in the U.S. and approximately 60,000 patients in Europe, typically middle-aged individuals, particularly women. The RESET-SScTM Phase 1/2 clinical trial of rese-cel is designed to treat six patients with severe skin manifestations and six patients with severe organ involvement associated with SSc. We announced the FDA granted Fast Track Designation for rese-cel for the treatment of patients with SSc to improve associated organ dysfunction and Orphan Drug Designation for rese-cel for the treatment of systemic sclerosis in January and March 2024, respectively. The trial is open for enrollment across multiple sites in the United States.

In November 2023, the FDA granted clearance of our rese-cel IND application for treatment of generalized myasthenia gravis, or gMG, a subset of patients with myasthenia gravis, or MG. MG is a rare autoimmune disease characterized by autoantibodies that interfere with signaling at the neuromuscular junction, or NMJ, leading to potentially life-threatening muscle weakness. The majority of patients with MG have autoantibodies known to be pathogenic based on their interference with proteins in the NMJ, of which the majority target AChR. gMG affects approximately 55,000 patients in the U.S. and approximately 100,000 patients in Europe. Symptoms of gMG include profound muscle weakness throughout the body, disabling fatigue, and potential shortness of breath due to respiratory muscle weakness, with risk for episodes of respiratory failure. Standard of care therapies include cholinesterase inhibitors, steroids, immunomodulators, and biologics, which typically require chronic administration, increasing the risk of serious long-term side effects. The RESET-MGTM Phase 1/2 clinical trial of rese-cel is designed to treat six patients with AChR-positive gMG and six patients with AChR-negative gMG, each in separate parallel cohorts. The trial is open for enrollment across multiple sites in the United States.

In May 2024, we announced that we are working with active clinical sites to incorporate the RESET-PVTM trial as a sub-study within the Phase 1 DesCAARTesTM trial following the submission of a protocol amendment. The RESET-PVTM trial will evaluate rese-cel as a monotherapy without preconditioning in patients with mucosal pemphigus vulgaris, or mPV, and mucocutaneous pemphigus vulgaris, or mcPV. Approximately 15,000 patients in the U.S. and approximately 20,000 patients in Europe are affected by PV. The trial is open for enrollment across multiple sites in the United States.

In June 2024, we announced the initial clinical data from each of the first two patients dosed with rese-cel in the RESET-SLETM and RESET-MyositisTM trials. In both of these patients, no cytokine release syndrome, or CRS, immune effector cell-associated neurotoxicity syndrome, or ICANS, infections or serious adverse events were observed through data cut-off of May 28, 2024. Rese-cel exhibited the anticipated profile of CAR T cell expansion and contraction with complete B cell depletion observed in both patients by day 15 post-infusion. Improvements in both patients’ specific disease measures were observed, consistent with academic experience of a similar 4-1BB CD19-CAR T.

In late June 2024, a lupus nephritis patient with very active, refractory disease was dosed with rese-cel and experienced Grade 1 CRS and a protocol-defined dose-limiting toxicity of Grade 4 ICANS. The ICANS resolved rapidly following standard management. The study’s Independent Data Monitoring Committee reviewed data from the patient, and recommended that the study proceed as designed, without delay, at the current dose. We recommended protocol modifications designed to improve patient safety, including enhanced monitoring for fever and neurologic symptoms along with seizure prophylaxis for all patients, in line with the practice at many academic sites including at Erlangen University, the site of the CD19-CAR T studies led by Dr. Georg Schett. In July 2024, we provided standard notice to the FDA and communicated details of the event and proposed protocol changes to all active clinical sites within the RESETTM clinical trial program, including the requirement that the investigator promptly discuss the appropriateness and timing of infusion with the trial’s Medical Monitor.

In November 2024, we announced updated clinical data at the American College of Rheumatology Convergence 2024 conference in the first 8 patients dosed across the lupus, myositis and systemic sclerosis clinical trials. Clinical data from these patients in the RESET-SLETM, RESET-MyositisTM trial and RESET-SSCTM trial were presented in oral and poster presentations where compelling clinical responses were observed in lupus and myositis patients with up to six months of follow-up, and the first SSc patient demonstrated an emerging, drug-free clinical response.

In January 2025, we announced the FDA granted clearance of our rese-cel IND application for treatment of multiple sclerosis, or MS. In addition, we announced the FDA granted Fast Track Designation for rese-cel for the treatment of relapsing and progressive forms of MS. The RESET-MSTM trial is a Phase 1/2 open-label, dose escalation study of rese-cel in subjects with relapsing and progressive forms of MS, evaluated in separate cohorts. Approximately 750,000 patients in the U.S. and approximately 550,000 patients in Europe are affected by MS.

97

In February 2025, we announced updated clinical and translational data from the first 10 patients in the RESETTM clinical trial program, with a data cut off of January 8, 2025. Overall, clinical responses continued to deepen over three SLE patients in DORIS remission, the first LN patient achieving complete renal response, and the first dermatomyositis patient maintaining a major total improvement score, or TIS improvement. Each of these patients discontinued all immunosuppressants and were off or tapering steroids as of January 8, 2025. The safety profile continued to suggest a favorable risk-benefit in the first 10 patients dosed with 90% of patients having experienced either no CRS or Grade 1 CRS and 90% of patients having experienced no ICANS.

In March 2025, we learned of an important protocol deviation in the RESET-SScTM trial. In this case, the patient reported a fever three days prior to infusion. The Cabaletta Medical Monitor was not notified by the investigator prior to the site infusing the patient. Nine days following rese-cel infusion, the patient experienced a dose-limiting toxicity of grade 3 immune effector cell-associated neurotoxicity syndrome (ICANS) based on a transient period of confusion. There was no cerebral edema, seizures or motor dysfunction associated with the ICANS event, and the patient was arousable throughout. The ICANS resolved rapidly following treatment with dexamethasone, and the patient was discharged without further symptoms. After data review, the Independent Data Monitoring Committee recommended that the trial proceed at the current dose without delay and endorsed our proposal to require investigators to affirmatively confirm in writing to the company the absence of fevers or evidence of infection. As of March 14, 2025, 56 clinical sites across the U.S. and Europe were actively recruiting with 33 patients enrolled across the RESETTM clinical trial program.

Our manufacturing strategy is comprised of two stages. The initial stage is designed to leverage the extensive early-stage manufacturing expertise of our academic partners and contract development and manufacturing organizations, or CDMOs, for rapid early development and clinical supply, and in parallel partner with commercially compliant CDMOs capable of supporting late-stage clinical studies and commercial production. Our aim is to achieve full manufacturing readiness through expanded CDMO relationships, establishment of our own manufacturing facilities, and/or through strategic partnership(s). We are leveraging the expertise in cell and vector manufacturing of our partners at the Children’s Hospital of Philadelphia, or CHOP, and the University of Pennsylvania, or Penn. For supply of lentiviral vector for the late-stage clinical and commercial manufacturing of rese-cel, we are working with Oxford Biomedica (UK) Limited, or Oxford. We have also collaborated with WuXi Advanced Therapies, Inc., or WuXi, to serve as an additional and commercially compliant cell manufacturing partner for our MusCAARTesTM and RESETTM clinical trials to meet planned capacity and international supply requirements. In July 2024, we entered into a new technology transfer agreement with Lonza Houston Inc., or Lonza, another commercially compliant CDMO, to execute a technology transfer of our expected commercial manufacturing process for rese-cel. In December 2024, we entered into a Development and Manufacturing Services Agreement, or the Lonza Agreement, with Lonza to serve as one of our manufacturing partners for the global clinical development of rese-cel in multiple indications, including potential late-stage clinical trials and preparations for commercial readiness. This improved process is nearly fully closed, semi-automated, and more easily scaled than the current process. Transfer of this updated process will be performed from Cabaletta to Lonza in anticipation of being able to supply rese-cel drug product for any of Cabaletta’s ongoing and planned RESETTM clinical trials. We plan to secure commercial, scalable manufacturing capabilities through multiple potential strategies, including expanding existing or establishing new CDMO relationships, leasing, building, qualifying and operating our own manufacturing facility, and/or establishing a strategic partnership to rapidly and reliably scale manufacturing by leveraging the partner’s manufacturing expertise. We believe this later stage will enable control of product development and commercial supply for products arising from our CABATM platform, enabling us to achieve continuous improvement of our product candidates. Multiple members of our team have previously built and led organizations that have constructed and commissioned cell therapy facilities, which we believe will enable us to build our own manufacturing organizations and facilities, if desirable.

As part of our innovative manufacturing strategy where we intend to increase scale, reduce cost of goods and improve patient experience, in November 2023, we partnered with Cellares Corp., or Cellares, to evaluate their automated manufacturing platform, the Cell ShuttleTM, through the Cellares Technology Adoption Program, or TAP. As part of the collaboration, the companies have agreed on a proof-of-concept technology transfer process for the automated manufacture and release testing of rese-cel. In August 2024, we expanded our partnership with Cellares to facilitate the potential to incorporate the Cellares manufacturing platform to support the RESETTM clinical program. In March 2025, we and Cellares announced the successful conclusion of the Technology Adoption Program on Cellares’ automated cell therapy manufacturing Cell ShuttleTM, facilitating the potential integration of the Cell ShuttleTM into our clinical and commercial, if approved, manufacturing strategy for rese-cel. We are also evaluating pathways to improve patient experience and scalability of collection through the removal of the requirement for apheresis. Data were published at the American Society of Cell and Gene Therapy conference in May 2024 illustrating the feasibility of this approach.

We were incorporated in April 2017 and started principal operations in August 2018. Our operations to date have been financed primarily by proceeds from the sale of convertible notes and convertible preferred stock prior to our initial public offering, or IPO, and proceeds from the sale of our common stock in public equity offerings, including our IPO, “at-the-market” offerings and

98

follow-on offerings of shares of our common stock and pre-funded warrants. As of December 31, 2024, we had $164.0 million in cash and cash equivalents.

99

Material Agreements

Refer to section titled “Business – Our Material Agreements” included in this annual report on Form 10-K for a discussion of our material agreements.

Components of Operating Results

Revenue

To date, we have not generated any revenue from product sales and do not expect to generate any revenue from the sales of products for several years, if at all. If our development efforts for our current or future product candidates are successful and result in marketing approval, we may generate revenue in the future from product sales. We cannot predict if, when or to what extent we will generate revenue from the commercialization and sale of our product candidates. We may never succeed in obtaining regulatory approval for any of our product candidates.

We may also in the future enter into license or collaboration agreements for our product candidates or intellectual property, and we may generate revenue in the future from payments as a result of such license or collaboration agreements.

Operating Expenses

Research and Development

Our research and development expenses include:

•

personnel costs, which include salaries, benefits and stock-based compensation expense;

•

expenses incurred under agreements with consultants and third-party contract organizations that conduct research and development activities on our behalf;

•

costs related to sponsored research service agreements;

•

costs related to production of preclinical and clinical materials, including fees paid to contract manufacturers;

•

licensing fees for intellectual property and know-how;

•

laboratory and vendor expenses related to the execution of preclinical studies and ongoing and planned clinical trials; and

•

laboratory supplies and equipment used for internal research and development activities and related depreciation expense.

We have not reported program costs since inception because historically we have not tracked or recorded our research and development expenses on a pre-clinical program-by-program basis. We use our personnel and infrastructure resources across the breadth of our research and development activities, which are directed toward identifying and developing product candidates.

We expense all research and development costs in the periods in which they are incurred. Costs for certain research and development activities are recognized based on an evaluation of the progress to completion of specific tasks using information and data provided to us by our vendors and third-party service providers.

We expect our research and development expenses to increase substantially for the foreseeable future as we continue to invest in research and development activities related to developing our product candidates, including investments in manufacturing, as our programs advance and we conduct clinical trials. The process of conducting the necessary clinical research to obtain regulatory approval is costly and time-consuming, and the successful development of our product candidates is highly uncertain. As a result, we are unable to determine the duration and completion costs of our research and development projects or when and to what extent we will generate revenue from the commercialization and sale of any of our product candidates.

100

Because of the numerous risks and uncertainties associated with product development, we cannot determine with certainty the duration and completion costs of the current or future preclinical studies and clinical trials or if, when, or to what extent we will generate revenues from the commercialization and sale of our product candidates. We may never succeed in achieving regulatory approval for our product candidates. The duration, costs and timing of preclinical studies and clinical trials and development of our product candidates will depend on a variety of factors, including:

•

successful completion of preclinical studies and IND and/or CTA-enabling studies;

•

development of chemistry, manufacturing and controls, or CMC, processes and procedures for purposes of IND and/or CTA applications;

•

successful patient enrollment in, and the initiation and completion of, clinical trials;

•

the impact of any business interruptions to our operations, including the timing and enrollment of patients in our ongoing and planned clinical trials, or to those of our clinical sites, manufacturers, suppliers, or other vendors resulting from public health crises;

•

receipt of regulatory approvals from applicable regulatory authorities;

•

establishing commercial manufacturing capabilities or arrangements with third-party manufacturers;

•

obtaining and maintaining patent and trade secret protection and non-patent exclusivity;

•

launching commercial sales of our product candidates, if and when approved, whether alone or in collaboration with others;

•

acceptance of our product candidates, if and when approved, by patients, the medical community and third-party payors;

•

effectively competing with other therapies and treatment options;

•

a continued acceptable safety and efficacy profile following approval;

•

enforcing and defending intellectual property and proprietary rights and claims; and

•

achieving desirable medicinal properties for the intended indications.

We may never succeed in achieving regulatory approval for any of our product candidates. We may obtain unexpected results from our preclinical studies and clinical trials. We may elect to discontinue, delay or modify clinical trials of some product candidates or focus on others. A change in the outcome of any of these factors could mean a significant change in the costs and timing associated with the development of our current and future preclinical and clinical product candidates. For example, if the FDA or another regulatory authority, were to require us to conduct clinical trials beyond those that we currently anticipate will be required for the completion of clinical development, or if we experience significant delays in execution of or enrollment in any of our preclinical studies or clinical trials, we could be required to expend significant additional financial resources and time on the completion of preclinical and clinical development. We expect our research and development expenses to increase for the foreseeable future as we continue the development of product candidates.

General and Administrative Expenses

Our general and administrative expenses consist primarily of personnel costs, costs related to maintenance and filing of intellectual property, depreciation expense and other expenses for outside professional services, including legal, human resources, information technology, audit and accounting services. Personnel costs consist of salaries, benefits and stock-based compensation expense. We expect our general and administrative expenses to increase over the next several years to support our continued research and development activities, manufacturing activities, increased costs of operating as a public company and the potential commercialization of our product candidates. We anticipate our general and administrative costs will increase with respect to the hiring of additional personnel, developing commercial infrastructure, fees to outside consultants, lawyers and accountants, and increased costs associated with being a public company such as expenses related to services associated with maintaining compliance with Nasdaq listing rules and SEC requirements, insurance and investor relations costs.

Other Income

Other income consists of interest earned on our cash, cash equivalents and short-term investments and amortization of bond discount or premium.

101

Interest Expense

Interest expense consists primarily of interest expense associated with finance lease arrangements.

Results of Operations for the years ended December 31, 2024 and 2023

The following sets forth our results of operations:

Year Ended December 31,

(in thousands)

Statements of Operations Data:

Operating expenses:

Other income:

Interest expense (748 ) — (748 )

Research and Development

Research and development expenses were $97.2 million for the year ended December 31, 2024 as compared to $55.4 million for the year ended December 31, 2023. The table below summarizes our research and development expenses:

Year Ended December 31,

(in thousands)

License of intellectual property $ 1,523 $ 2,383 $ (860 )

Manufacturing of preclinical and clinical supplies 15,523 8,498 7,025

Specific changes in our research and development expenses year over year include a:

•

$16.9 million increase in personnel costs primarily driven by an increase in headcount to support overall growth related to our rese-cel program, including an increase of $4.6 million in stock-based compensation expense;

•

$14.0 million increase in clinical trial costs primarily due to rese-cel clinical trial costs;

•

$7.0 million increase in manufacturing costs primarily due to expanded cell processing capabilities and related activities;

•

$3.9 million increase in development services due to expanded lab space and related costs to support increased headcount performing research and translational activities;

•

$0.8 million increase in other primarily due to increased travel, conference and training costs and other costs to support headcount growth; partially offset by a

102

•

$0.9 million decrease in license of intellectual property costs due to a $1.2 million upfront fee to Autolus pursuant to the Autolus Option and License Agreement and a $1.0 million milestone payment to IASO for IND clearance of rese-cel in the first quarter of 2023 compared to a $1.5 million milestone payment to IASO in the first quarter of 2024 for the first patient dosed in the rese-cel trial.

General and Administrative Expenses

General and administrative expenses were $27.9 million for the year ended December 31, 2024 as compared to $19.2 million for the year ended December 31, 2023. The increase of $8.7 million in our general and administrative expenses year over year includes:

•

$6.5 million of additional personnel costs, primarily driven by an increase in headcount to support overall company growth, including an increase of $3.5 million in stock-based compensation expense; and

•

$2.2 million higher administrative costs, including legal, information technology, and travel as well as other administrative costs.

Other Income

Interest income has increased $3.0 million for the year ended December 31, 2024 as compared to the year ended December 31, 2023, primarily as a result of increasing interest rates on a higher cash and cash equivalents balance due to a financing in May 2023 and proceeds from sales of common stock pursuant to the ATM Program in the fourth quarter of 2023, first quarter of 2024 and fourth quarter of 2024.

Interest Expense

Interest expense has increased $0.8 million for the year ended December 31, 2024 as compared to the year ended December 31, 2023, primarily as a result of finance lease arrangements from embedded leases within our WuXi manufacturing agreement.

Liquidity, Capital Resources and Going Concern

From our inception in April 2017 to the time of our initial public offering, or IPO, our operations were financed by proceeds of $86.4 million from the sale of convertible notes and our convertible preferred stock and proceeds of $71.0 million from the sale of common stock in our IPO. Since our IPO, we have generated cash from public offerings of our common stock and pre-funded warrants to purchase our common stock resulting in aggregate net proceeds of approximately $280.0 million. As of December 31, 2024, we had $164.0 million in cash and cash equivalents which should enable us to fund our operations and capital expenditures into the first half of 2026. Cash in excess of immediate requirements is invested in accordance with our investment policy, primarily with a view to liquidity and capital preservation.

We have incurred losses since our inception and, as of December 31, 2024, we had an accumulated deficit of $349.1 million. Our primary use of cash is to fund operating expenses, which consist primarily of research and development expenditures, and to a lesser extent, general and administrative expenditures. Cash used to fund operating expenses is impacted by the timing of when we pay these expenses, as reflected in the change in our outstanding prepaid expenses and other current assets, accounts payable and accrued expenses.

Any product candidates we may develop may never achieve commercialization and we anticipate that we will continue to incur losses for the foreseeable future. We expect that our research and development expenses, general and administrative expenses, and capital expenditures will continue to increase. As a result, until such time, if ever, as we can generate substantial product revenue, we expect to finance our cash needs through a combination of equity offerings, debt financings or other capital sources, including potentially collaborations, licenses and other similar arrangements. Our primary uses of capital are, and we expect will continue to be, compensation and related expenses, third-party clinical research, manufacturing and development services, costs relating to the build-out of our headquarters, laboratories and manufacturing facility, license payments or milestone obligations that may arise, laboratory and related supplies, clinical costs, manufacturing costs, legal and other regulatory expenses and general overhead costs.

We evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about our ability to continue as a going concern within one year after the date that the consolidated financial statements are issued. Based on our current operating plan, we believe there is substantial doubt about our ability to continue as a going concern for at least twelve months following the filing of this Annual Report on Form 10-K, and we will need to obtain additional funding. Our cash forecast

103

contains estimates and assumptions based on success of ongoing clinical trials, and we cannot predict the amount or timing of all expenditures with certainty. We will continue to seek funds through equity offerings, debt financings or other capital sources, including potentially collaborations, licenses and other similar arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. If we do raise additional capital through public or private equity offerings, the ownership interest of our existing stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect our stockholders’ rights. If we raise additional capital through debt financing, we may be subject to covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. Any failure to raise capital as and when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to raise capital, we will need to delay, reduce or terminate certain planned activities to reduce costs.

At-The-Market Offering Sales Agreement

On March 21, 2024, we filed an automatic shelf registration statement (File No. 333-278126), or 2024 S-3ASR, in relation to the registration of common stock, preferred stock, debt securities, warrants and/or units of any combination thereof for the purposes of selling, from time to time, our common stock, debt securities or other equity securities in one or more offerings. We also simultaneously entered into a Sales Agreement, or the 2024 Sales Agreement, with Cowen and Company, LLC, or the Sales Agent, to provide for the offering, issuance and sale of up to an aggregate amount of $200.0 million of our common stock from time to time in “at-the-market” offerings, or the 2024 ATM Program, under the 2024 S-3ASR and subject to the limitations thereof. We intend to convert the S-3ASR to S-3 by post-effective amendments in connection with the filing of this Annual Report. In December 2024, we sold 1,225,000 shares pursuant to the 2024 ATM Program for net proceeds of $5.1 million, after deducting commissions of $0.1 million.

We previously had a Sales Agreement with Cowen to provide for the offering, issuance and sale of up to an aggregate amount of $100.0 million of common stock from time to time in “at-the-market” offerings, or 2023 ATM Program, pursuant to our shelf registration statement on Form S-3 (File No. 333-270599), which was declared effective April 26, 2023. During the year ended December 31, 2023, we sold 4,760,899 shares pursuant to the 2023 ATM Program for net proceeds of $91.7 million, after deducting commissions of $2.4 million. In the first quarter of 2024, we sold 258,070 additional shares, completing the 2023 ATM Program for net proceeds of $5.7 million, after deducting commissions of $0.1 million.

December 2022 Financing

In December 2022, we issued 126,815 shares of our common stock at a price of $5.52 per share and to certain investors in lieu of common stock, pre-funded warrants to purchase 6,213,776 shares of our common stock at a price of $5.51999 per pre-funded warrant. The purchase price per share of each pre-funded warrant represents the per share offering price for the common stock, minus the $0.00001 per share exercise price of such pre-funded warrant. Aggregate net proceeds were $32.6 million after deducting underwriting discounts and commissions and offering expenses of $2.4 million. As of December 31, 2024, 6,213,775 pre-funded warrants had been exercised and no warrants remain outstanding.

May 2023 Financing

In May 2023, we issued 8,337,500 shares of our common stock in an underwritten public offering, including the exercise in full by the underwriters of their option to purchase an additional 1,087,500 shares, at a public offering price of $12.00 per share. Aggregate net proceeds were $93.8 million after deducting underwriting discounts and commissions and offering expenses of $6.3 million.

Because of the numerous risks and uncertainties associated with research, development and commercialization of pharmaceutical products, we are unable to estimate the exact amount of our operating capital requirements. Our future funding requirements will depend on many factors, including, but not limited to:

•

the scope, progress, results and costs of researching, developing and manufacturing our lead product candidates or any future product candidates, and conducting preclinical studies and clinical trials;

•

the timing of, and the costs involved in, obtaining regulatory approvals or clearances for our lead product candidates or any future product candidates;

•

the impact of any business interruptions to our operations or to those of our clinical sites, manufacturers, suppliers, or other vendors resulting from public health crises;

104

•

the number and characteristics of any additional product candidates we develop or acquire;

•

the timing of any cash milestone payments if we successfully achieve certain predetermined milestones;

•

the cost of manufacturing our lead product candidate or any future product candidates and any products we successfully commercialize, including costs associated with building-out our manufacturing capabilities;

•

our ability to establish and maintain strategic collaborations, licensing or other arrangements and the financial terms of any such agreements that we may enter into;

•

the expenses needed to attract and retain skilled personnel;

•

the costs associated with being a public company; and

•

the timing, receipt and amount of sales of any future approved or cleared products, if any.

Further, our operating plans may change, and we may need additional funds to meet operational needs and capital requirements for clinical trials and other research and development activities. We currently have no credit facility or committed sources of capital. Because of the numerous risks and uncertainties associated with the development and commercialization of our product candidates, we are unable to estimate the amounts of increased capital outlays and operating expenditures associated with our current and anticipated product development programs.

Cash Flows

The following table summarizes our cash flows for the periods indicated:

Year Ended December 31,

(in thousands)

Net cash provided by (used in):

Effect of exchange rate changes on cash and cash equivalents (20 ) —

Net (decrease) increase in cash and cash equivalents $ (29,276 ) $ 111,631

Operating Activities

During the year ended December 31, 2024, cash used in operating activities of $88.2 million was attributable to our net loss of $115.9 million, partially offset by non-cash charges of $26.0 million for stock-based compensation charges, amortization of finance lease, non-cash operating lease expense, depreciation, amortization of premium on investments, accretion of operating lease liabilities and foreign currency exchange rates and a net change of $1.7 million in our net operating assets and liabilities.

During the year ended December 31, 2023, cash used in operating activities of $53.5 million was attributable to our net loss of $67.7 million, partially offset by non-cash charges of $14.1 million for stock-based compensation charges, amortization of premium on investments, non-cash lease expense, accretion of lease liabilities and depreciation and a net change of $0.1 million in our net operating assets and liabilities.

Investing Activities

During the year ended December 31, 2024, cash provided by investing activities of $47.3 million was attributable to $49.5 million from the maturity of short-term investments, partially offset by purchases of $2.2 million of property and equipment.

During the year ended December 31, 2023, cash used in investing activities of $22.5 million was attributable to $84.3 million of purchases of investments and $0.7 million of purchases of property and equipment, partially offset by $62.5 million of proceeds from maturities of investments.

105

Financing Activities

During the year ended December 31, 2024, cash provided by financing activities of $11.7 million was from $10.9 million in sales of common stock, net of issuance costs paid, $1.7 million from the exercise of employee stock and purchases of shares under our 2019 Employee Stock Purchase Plan, or 2019 ESPP, offset by $0.9 million in principal payments on finance leases.

During the year ended December 31, 2023, cash provided by financing activities of $187.6 million was from $185.2 million in sales of common stock, net of issuance costs paid and $2.4 million from the exercise of employee stock options and purchases of shares under our 2019 ESPP.

Contractual Obligations and Commitments

We lease our headquarters office space and lab space under non-cancelable operating lease agreements. The lease term of our office space commenced in May 2019 and was amended in October 2024 for an additional 12 months through June 30, 2026. The lease term of our lab space was amended in September 2024 for 23 months through August 2026. See Note 9 of the consolidated financial statements for additional detail on our leases. We also have an embedded lease with WuXi, our cell processing manufacturing partner through August 2026. Total undiscounted aggregate future finance and operating lease obligations under all of our leases as of December 31, 2024 are $17.1 million.

We have no material contractual obligations not fully recorded on our balance sheets or fully disclosed in the notes to the consolidated financial statements. Our commitments include:

•

IASO Exclusive License Agreement. As partial consideration for the exclusive license, IASO received an upfront payment of $2.5 million. IASO is also eligible to receive up to mid double digit millions in milestone payments based upon the achievement of specified pre-clinical, development and regulatory milestones, and up to an additional low triple digit millions in milestone payments based upon achievement of specified sales milestones, for a total consideration, inclusive of the upfront payment, of up to $162 million, along with tiered mid-single digit royalties on future net sales for licensed products that may result from the IASO Agreement. We also may sublicense through multiple tiers the rights granted to it by IASO under the IASO Agreement at any time, however, we must pay IASO a low double-digit percentage of any revenue obtained from sublicenses or options to third parties, subject to certain customary exclusions. The IASO Agreement will continue on a country-by-country, licensed product-by-licensed product basis until the expiration of the royalty term as identified in the IASO Agreement, unless earlier terminated. A milestone payment of $1.5 million was paid to IASO in the first quarter of 2024 after the first patient in a rese-cel trial was dosed.

•

Oxford Licence and Supply Agreement. Under the terms of the agreement, we were required to pay Oxford an upfront fee, as well as costs associated with initial vector manufacturing activities for our DSG3-CAART program. In May 2023, we amended the LSA with Oxford to expand the license to include our rese-cel program for an upfront fee of $0.5 million and in August 2023, we entered into a vector supply agreement with Oxford, and a related second amendment to the LSA, for rese-cel with a total cost of up to approximately $5.0 million under the vector supply agreement. In February 2024, the Company and Oxford entered into a third amendment to the LSA to update the patent schedule. We can terminate the agreement at will upon advance written notice and subject to certain manufacturing slot cancellation fees.

•

Autolus Option and License Agreement. In January 2023, we entered into an Option and License Agreement, or the Autolus Agreement, with Autolus Holdings (UK) Limited (Autolus), wherein the Autolus Agreement grants us a non-exclusive license to access Autolus' RQR8 technology in our CD19-CAR T cell therapy program, and subject to additional nominal option exercise fees, up to four additional targets. In January 2025, the Company and Autolus agreed to novate the Autolus Agreement with both Autolus and Autolus Limited jointly assuming the rights, obligations and liabilities of Autolus under the Autolus Agreement. Under the terms of the Autolus Agreement, we were required to pay Autolus an upfront license fee of $1.2 million, of which $1.1 million was paid in 2023 and $0.1 million was paid in January 2024. Autolus is also eligible to receive regulatory milestones of up to $12 million for each licensed target, sales milestones of up to a total of $15 million and royalties in the low single digits on net sales of all products that incorporate the RQR8 technology. The Autolus Agreement will continue on a country-by-country, licensed product-by-licensed product basis until the expiration of the royalty term as identified in the Autolus Agreement, unless earlier terminated. We can terminate the Autolus Agreement at will upon advance written notice. Each of Autolus and us may terminate the Agreement for a material, uncured breach or insolvency of the other party.

106

•

The Penn License Agreement. Under the License Agreement, we are required to make milestone payments upon successful completion of certain development, regulatory and sales milestones on a product-by-product and geographical basis. The payment obligations under the License Agreement are contingent upon future events such as our achievement of specified development, regulatory and commercial milestones and we will be required to make development milestone payments and royalty payments in connection with the sale of products developed under the License Agreement. As of December 31, 2024, we are unable to estimate the timing or likelihood of achieving the milestones or making future product sales.

Under the License Agreement, we must use commercially reasonable efforts to develop and commercialize a product in each subfield. During the term of the License Agreement until the first commercial sale of the first product, we are obligated to pay Penn a non-refundable, non-creditable annual license maintenance fee of $10,000. We are required to pay certain milestone payments upon the achievement of specified clinical and commercial milestones. Milestone payments are reduced by a certain percentage for the second product that achieves a milestone, by an additional percentage for the third product that achieves a milestone, and so on, for each subsequent product that achieves a milestone. In the event that we are able to successfully develop and launch multiple products under the License Agreement, total milestone payments could be approximately $21.0 million. Penn is also eligible to receive tiered royalties at percentage rates in the low single-digits, subject to an annual minimum royalty, on annual worldwide net sales of any products that are commercialized by us or our sublicensees that contain or incorporate, or are covered by, the intellectual property licensed by us. To the extent we sublicense our license rights under the License Agreement, Penn would be eligible to receive tiered sublicense income at percentage rates in the mid-single to low double-digits. We have also entered into a subscription and technology transfer agreement with Penn, pursuant to which we owed Penn an upfront subscription fee, which was paid in 2019, and a nominal non-refundable royalty on net sales of products, a portion of which will be credited toward milestone payments and royalties under this License Agreement. Technology transfer activities would be at our cost and subject to agreement as to the technology to be transferred.

•

Master Translational Research Services Agreement with Penn. Under the Services Agreement, we have contracted for additional research and development services from various laboratories within Penn. The Services Agreement will expire upon completion of the services for which we have engaged Penn under the Services Agreement. In May 2020, the Company amended its Addendum with CAROT to expand access to vector manufacturing. We may incur additional expenses up to $0.6 million through the remaining term of the CAROT Amended Addendum. In February 2023, we entered into a second Master Translational Research Services Agreement with Penn, or the CARTA Services Agreement, pursuant to which Penn agreed to perform certain research, development and manufacturing activities. The services encompassed by the CARTA Services Agreement are performed by different organizations at Penn pursuant to certain addenda to the CARTA Services Agreement. The CARTA Services Agreement will expire on the later of (i) February 9, 2026 or (ii) completion of the services for which we have engaged Penn under the CARTA Services Agreement. Either party may terminate this agreement with or without cause upon a certain number of days’ prior written notice. We are committed to pay up to $3.0 million for cell processing manufacturing under the CARTA Services Agreement through December 31, 2025.

•

WuXi Manufacturing agreement. In January 2021, we entered into the WuXi Agreement to serve as an additional cell processing manufacturing partner for the MusCAARTesTMtrial. In August 2023, we entered into new work orders under the WuXi Agreement for WuXi to serve as one of our cell processing manufacturing partners for the global clinical development of rese-cel in multiple indications, including potential late-stage clinical trials and commercial readiness activities for rese-cel. Under the August 2023 work orders, WuXi will convert our non-dedicated suite to a dedicated suite for GMP manufacturing for our rese-cel and MuSK-CAART programs for an initial term of 18 months with two 18 month extensions at our sole option on six months' notice prior to the end of the term. In addition, we agreed to certain monthly minimum runs. We would incur up to a $1.08 million termination fee if we terminate both the rese-cel and MuSK-CAART work orders for any reason. We may terminate for convenience the WuXi Agreement or any work order with six months' prior written notice, however, we may not terminate the Dedicated Suite without terminating both the MuSK-CAART and rese-cel GMP run work orders.

107

•

Lonza Manufacturing agreement. In December 2024, we entered into the Lonza Agreement with Lonza to serve as one of our manufacturing partners for the global clinical development of rese-cel in multiple indications, including potential late-stage clinical trials and preparations for commercial readiness. Under the initial work order, Lonza will perform cell therapy manufacturing activities for our CAR-T cell therapy product rese-cel for a term of 12 months and total cost of approximately $16.0 million with the ability to extend the manufacturing period subject to the terms of the Lonza Agreement.

•

Other Purchase Commitments. In the normal course of business, we enter into various purchase commitments with third-party contract manufacturers for the manufacture and processing of our product candidates and related raw materials, contracts with contract research organizations for clinical trials and agreements with vendors for other services and products for operating purposes. These agreements generally provide for termination or cancellation other than for costs already incurred.

Critical Accounting Policies and Significant Judgments and Estimates

Our management’s discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements, which have been prepared in accordance with generally accepted accounting principles, or GAAP. The preparation of these consolidated financial statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, as well as the reported expenses incurred during the reporting periods. Our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. We believe that the accounting policies discussed below are critical to understanding our historical and future performance, as these policies relate to the more significant areas involving management’s judgments and estimates.

While our significant accounting policies are described in more detail in Note 2 to our consolidated financial statements appearing elsewhere in this Annual Report, we believe that the following accounting policies are those most critical to the judgments and estimates used in the preparation of our consolidated financial statements.

Research and Development Costs

We estimate costs of research and development activities conducted by service providers, which include the conduct of preclinical studies, contract manufacturing activities and clinical trial activities. We record the estimated costs of research and development activities based upon the estimated amount of services provided and include these costs in the accrued and other current liabilities on the balance sheets and within research and development expense on the statements of operations. Non-refundable advance payments made for goods or services that will be used or rendered for future research and development activities are deferred and capitalized and recognized as expense as the goods are received or the related services are rendered.

We estimate these costs based on factors such as estimates of the work completed and budget provided and in accordance with agreements established with our collaboration partners and third-party service providers. We make significant judgments and estimates in determining the accrued liabilities balance in each reporting period. As actual costs become known, we adjust our accrued liabilities. We have not experienced any material differences between accrued costs and actual costs incurred since our inception.

108

Smaller Reporting Company Status

We are a “smaller reporting company,” as defined in Rule 12b-2 under the Securities Exchange Act of 1934, as amended. We would cease to be a smaller reporting company if we have a public float in excess of $250 million, or have annual revenues in excess of $100 million and a public float in excess of $700 million, determined on an annual basis. This status allows us to take advantage of many of the same exemptions from disclosure requirements including not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act and reduced disclosure obligations regarding executive compensation in our periodic reports and proxy statements.

Recently Adopted Accounting Pronouncements

For a discussion of recently adopted accounting pronouncements please read Note 2, Summary of Significant Accounting Policies, to our consolidated financial statements included in this report.

Recently Issued Accounting Pronouncements

For a discussion of recently issued accounting pronouncements please read Note 2, Summary of Significant Accounting Policies, to our consolidated financial statements included in this report.

109

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

We are exposed to market risks in the ordinary course of our business. These risks primarily include interest rate sensitivities. We held cash and cash equivalents of $164.0 million as of December 31, 2024. We generally hold our cash in interest-bearing money market treasury fund accounts. Our primary exposure to market risk is interest rate sensitivity, which is affected by changes in the general level of U.S. interest rates. Due to the short-term maturities of our cash equivalents, an immediate 100 basis point change in interest rates would not have a material effect on the fair market value of our cash equivalents. Declines in interest rates, however, would reduce future investment income.

We do not have any foreign currency or derivative financial instruments. Inflation generally affects us by increasing our cost of labor and program costs. Although we do not believe that inflation has had a material impact on our financial position or results of operations to date, we may experience some effect in the near future (especially if inflation rates continue to rise) due to an impact on the costs to conduct clinical trials, labor costs we incur to attract and retain qualified personnel, and other operational costs. Inflationary costs could adversely affect our business, financial condition and results of operations.

Item 8. Consolidated Financial Statements and Supplementary Data.

The consolidated financial statements required to be filed pursuant to this Item 8 are appended to this Annual Report. An index of those consolidated financial statements is found in Item 15.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure.

There has been no change of accountants nor any disagreements with accountants on any matter of accounting principles or practices of financial disclosure required to be reported under this Item.

110

Item 9A. Controls and Procedures.

Evaluation of Disclosure Controls and Procedures

The Company has established disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act) designed to ensure that information required to be disclosed in the reports that the Company files or submits under the Securities Exchange Act of 1934, as amended, or Exchange Act, is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms and is accumulated and communicated to management, including the principal executive officer (our Chief Executive Officer) and principal financial officer (our Chief Financial Officer), to allow timely decisions regarding required disclosure. In addition, the design of disclosure controls and procedures must reflect the fact that there are resource constraints and that management is required to apply judgment in evaluating the benefits of possible controls and procedures relative to their costs.

Our management, with the participation of our Chief Executive Officer and Chief Financial Officer, evaluated, as of December 31, 2024, the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act). Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Our disclosure controls and procedures have been designed to provide reasonable assurance of achieving their objectives. Based on that evaluation, our Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act) were effective at the reasonable assurance level as of December 31, 2024.

Management’s Annual Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is a process designed to provide reasonable assurance of the reliability of financial reporting and of the preparation of consolidated financial statements for external reporting purposes, in accordance with U.S. generally accepted accounting principles.

Internal control over financial reporting includes policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect transactions and disposition of assets; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of consolidated financial statements in accordance with U.S. generally accepted accounting principles, and that receipts and expenditures are being made only in accordance with the authorization of its management and directors; and (3) provide reasonable assurance regarding the prevention or timely detection of unauthorized acquisition, use, or disposition of our assets that could have a material effect on its consolidated financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of the effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies and procedures included in such controls may deteriorate.

Our management has assessed the effectiveness of our internal control over financial reporting as of December 31, 2024. In making this assessment, management used the criteria established by the Committee of Sponsoring Organizations of the Treadway Commission (COSO) in Internal Control - Integrated Framework (2013). These criteria are in the areas of control environment, risk assessment, control activities, information and communication, and monitoring. Management’s assessment included extensive documentation, evaluating and testing the design and operating effectiveness of its internal controls over financial reporting.

Based on management’s processes and assessment, as described above, management has concluded that, as of December 31, 2024, our internal control over financial reporting was effective.

Attestation Report of the Registered Public Accounting Firm

As a non-accelerated filer, we are not required to provide an attestation report of our independent registered public accounting firm on the effectiveness of our internal control over financial reporting.

111

Changes in Internal Control over Financial Reporting

There was no change in our internal control over financial reporting (as defined in Rule 13a-15(f) of the Exchange Act) that occurred during the fiscal quarter ended December 31, 2024 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

Item 9B. Other Information.

Rule 10b5-1 Trading Plans

During the fiscal quarter ended on December 31, 2024, none of our directors and officers (as defined in Rule 16a-1(f) under the Exchange Act) adopted, modified or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as those terms are defined in Item 408(a) of Regulation S-K, except as described in the table below:

* Denotes whether the trading plan is intended, when adopted, to satisfy the affirmative defense of Rule 10b5-1(c).

(1) Except as indicated by footnote, each trading arrangement permitted or permits transactions through and including the earlier to occur of (a) the completion of all purchases or sales or (b) the date listed in the table.

(2) Represents the modification, as described in Rule 10b5-1(c)(1)(iv) under the Exchange Act, of a written trading arrangement adopted on November 9, 2023 that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections.

Not applicable.

112

PART III

Item 10. Directors, Executive Officers and Corporate Governance.

The following table sets forth information about our directors and executive officers as of March 27, 2025.

Executive Officers

Gwendolyn K. Binder, Ph.D. President, Science and Technology 2019 — 50

Anup Marda, MBA Chief Financial Officer 2019 — 47

David J. Chang, M.D., M.P.H. Chief Medical Officer 2019 — 62

Michael Gerard, J.D. General Counsel and Secretary 2021 — 45

Arun Das, M.D. Chief Business Officer 2022 — 35

Non-Employee Directors

Catherine Bollard, MBChB, M.D. (3) Director 2019 Class II—2027 57

(1) Member of the Audit Committee.

(2) Member of the Compensation Committee.

(3) Member of the Nominating and Corporate Governance Committee.

Executive Officers

Steven Nichtberger, M.D. Dr. Nichtberger has served as our Chief Executive Officer, President and Chairman of our board of directors since our founding in 2017. He is also a Professor of Professional Practice in the Vagelos LSM program and adjunct professor at The Wharton School of the University of Pennsylvania in addition to being a member of the board of directors of the BioAdvance Greenhouse Fund. Previously, Dr. Nichtberger served as president, chief executive officer, and a member of the board of directors of Tengion, Inc. from 2004 to 2011. In 2008, his leadership was recognized nationally with the National Ernst & Young Entrepreneur of the Year Award for emerging companies. Earlier in his career, Dr. Nichtberger served as the head of global marketing for Merck and in various commercial operating roles at the company from 1995 to 2003. He has previously served as a member of the boards of directors of the Alliance for Regenerative Medicine (as a founding member), Pennsylvania Bio (including as chairman), and Biotechnology Industry Organization. From 2008 to 2019, he was a member of the board of overseers for the School of Arts & Sciences at the University of Pennsylvania. Dr. Nichtberger received his M.D. from the State University of New York at Buffalo, his B.S. from The Wharton School at the University of Pennsylvania and his B.A. from the University of Pennsylvania. He completed internship, residency and fellowship in the Department of Medicine and the Division of Cardiology of the Mount Sinai Medical Center in New York. We believe Dr. Nichtberger is qualified to serve as a member and Chairman of our board of directors because of his scientific and medical background as well as his corporate leadership experience.

Gwendolyn K. Binder, Ph.D. Dr. Binder joined our company in February 2019 as our Executive Vice President, Science and Technology and was appointed President, Science and Technology in January 2022. Dr. Binder is an R&D executive with specialized expertise in the discovery and early clinical development and optimization of engineered T cell therapies. Prior to joining Cabaletta, Dr. Binder was the Chief Technology Officer of Adaptimmune Therapeutics Plc from March 2016 to January 2019, where she ultimately led the research team focusing on understanding mechanisms of tumor response and resistance and translating this understanding to next generation products and clinical study designs. In prior roles, from March 2011 to February 2016, she established and led the translational research group, in addition to the manufacturing and quality teams including oversight of the buildout of an in-house manufacturing facility. Earlier in her career, Dr. Binder served as Director of Operations for the Translational Research Program at the University of Pennsylvania, where she where she progressed multiple investigational new drug submissions for novel engineered T-cell therapies in HIV and oncology, including the CD19 CAR IND acquired by Novartis (now Kymriah), the first human gene editing IND, and three TCR engineered T cell therapy studies in oncology and HIV. Prior to that, she served as the

113

Director of Scientific Affairs at VIRxSYS Corporation in Gaithersburg Maryland where she supported the development of the first clinical lentiviral vector used in humans, for the application of engineered T cell therapy for HIV. In addition, Dr. Binder has served on the Board of Directors of Instil Bio (Nasdaq: TIL), a clinical-stage biopharmaceutical company focused on developing a pipeline of novel therapies including a lead PD-L1xVEGF bispecific antibody for solid tumors, since July 2020, and as a member of the Scientific Advisory Board for Immatics, which is a publicly traded company developing engineered T cell immunotherapy for cancer, since July 2020. Dr. Binder studied viral immunology and translational research at the Johns Hopkins University in Baltimore, Maryland where she earned a Ph.D. in Cellular and Molecular Medicine in 2002. She has authored over 30 publications in the field, including top international journals such as “Science”, and “Nature Medicine”. She is a recognized leader in the biotechnology sector for the translational and clinical advancement of novel T cell therapies for patients with serious diseases.

Anup Marda, MBA. Mr. Marda joined our company in January 2019 as our Chief Financial Officer. From April 2001 to January 2019, Mr. Marda held positions at Bristol-Myers Squibb, including, most recently, as Vice President, Head of Global Corporate Financial Planning & Analysis, and previously as Head of Finance, R&D Operations and Head of Finance, R&D Portfolio Management and Global Medical from 2014 to 2018. Prior to this, Mr. Marda held the role of Executive Director, U.S. Pharmaceuticals from 2012 to 2014 and Assistant Treasurer, Capital Markets from 2008 to 2012. Mr. Marda received his MBA from the Krannert School of Business of Purdue University and his B.Tech in Chemical Engineering from the Indian Institute of Technology Bombay.

David J. Chang, M.D., M.P.H. Dr. Chang joined our company in June 2019 as our Chief Medical Officer. From June 2015 to May 2019, he was Senior Vice President and Head, Inflammation, Autoimmunity & Neuroscience, or IA&NS, Global Medicines Development at AstraZeneca Pharmaceuticals LP, where he oversaw development projects of both biologics and small molecules in a variety of indications and led the late-stage clinical development organization for IA&NS. From October 2007 to June 2015, Dr. Chang served in various positions at GlaxoSmithKline plc, including VP and Head, Immuno-Inflammation, Clinical Development. While at AstraZeneca and GlaxoSmithKline, he provided leadership in driving the clinical development and registration of the only two products approved for systemic lupus erythematosus in the US in over 60 years. He received his M.D. from New York University School of Medicine, his M.P.H. from Emory University and his B.S. from Yale University. Dr. Chang completed his internship and residency in internal medicine at the New York Hospital—Cornell University Medical Center and fellowship in rheumatology at the Hospital for Special Surgery—Cornell University Medical Center.

Michael Gerard, J.D. Mr. Gerard joined our company in September 2021 as our General Counsel and Secretary. Prior to joining Cabaletta, Mr. Gerard served as Associate General Counsel of Spark Therapeutics, Inc., or Spark, from September 2020 to August 2021. Prior to Spark, Mr. Gerard served in various legal roles at Sandoz, Inc., a division of the Novartis Group, beginning in 2013, with the most recent role being Executive Director, Associate General Counsel, Business Development and Licensing, Strategy and Portfolio. Earlier in his career, Mr. Gerard served as Assistant General Counsel at Aramark and as a litigator at the law firms of Morrison & Foerster, LLP and K&L Gates, LLP in New York. Mr. Gerard received a B.A. in Political Science from the University of Michigan, Ann Arbor and a J.D. from Cornell Law School.

Arun Das, M.D. Dr. Das joined our company in July 2019 after serving as a consultant to the company since 2017, and served in several roles, most recently Executive Director of New Product Planning and Business Development, prior to being appointed Chief Business Officer in January 2022. He is also a Lecturer in the Health Care Management Department at the Wharton School of the University of Pennsylvania. Prior to joining Cabaletta, Dr. Das was a resident physician in General Pediatrics at the Children’s Hospital of Philadelphia from June 2018 to June 2019. Previously, he was an investment banking analyst in the healthcare group at Goldman Sachs from 2010 to 2012. In addition, Dr. Das has spent multiple years consulting in business development and operations for several start-ups in the biotechnology space. Dr. Das received his M.D. from Johns Hopkins University School of Medicine and a B.A. and B.S. dual degree from the University of Pennsylvania.

Non-Employee Directors

Mark Simon, MBA. Mr. Simon joined our board of directors in October 2018. He is a Strategic Advisor since 2020 to the Founder and CEO of Sun Pharmaceutical Industries Ltd., which is the largest pharmaceutical company in India, and a board observer of Sun Pharma Advanced Research Company Ltd., both public companies in India, where Mr. Simon is focused on accelerating their innovation initiatives. He is also a consultant to Stifel Nicolaus & Company (NYSE: SF) and co-founder of Torreya Partners, LLC, a global investment banking firm serving companies in the life sciences industry that Stifel acquired in 2023. Prior to co-founding Torreya, Mr. Simon was a managing director and head of life sciences investment banking at Citigroup from 2002 to 2005 where he covered global pharmaceutical companies with a focus on large-capitalization players in the U.S., Europe and Japan. Prior to Citigroup, Mr. Simon served as a Managing Director at Robertson Stephens in San Francisco and New York where he was responsible for covering the biotechnology investment banking sector. During his tenure overseeing the group, he was involved in raising 45% of all biotechnology dollars raised in the U.S. from 1999-2001. Prior to joining the investment banking group, Mr.

114

Simon was a senior biotechnology research analyst at Robertson Stephens, and was named a Wall Street All-Star Analyst for three years in a row. He began his career at Kidder Peabody as a biotechnology research associate in 1984 and participated in the IPO of Genzyme and the early financings of companies such as Amgen. Mr. Simon currently serves on the boards of directors of several disease advocacy and philanthropic foundations in the oncology, CNS/neuroscience and metabolic areas. He previously served on the board of directors of Portage Biotech Inc. (Nasdaq: PRTG) until April 2024. Mr. Simon received his MBA from Harvard Business School and his B.A. from Columbia College. We believe that Mr. Simon is qualified to serve on our board of directors because of his extensive experience of over 35 years in the life sciences industry and biotechnology and specialty pharmaceutical transactions.

Scott Brun, M.D. Dr. Brun joined our board of directors in June 2021. Dr. Brun is currently President at Gold Mast Consulting, LLC, an advisory firm he founded in 2019 to provide technical advice and strategic guidance related to biopharmaceutical research and development, pipeline portfolio management, commercialization of new therapeutics and strategic communications related to R&D activities. Dr. Brun serves as a Venture Partner at Abingworth LLP and a Senior Medical Advisor to Launch Therapeutics. Prior to his current roles, Dr. Brun had two decades of experience in various leadership roles at AbbVie, Inc., including 15 years at the predecessor company, Abbott Laboratories. The majority of his career has been focused on leading teams and clinical development organizations across a broad variety of therapeutic areas including autoimmune, neurologic, and renal among others. He was most recently Corporate Vice President of Scientific Affairs and Head of AbbVie Ventures, a corporate venture fund responsible for investment opportunities within AbbVie’s R&D therapeutic areas as well as technology platforms of interest from 2016 to 2019. Previously, Dr. Brun served as Corporate Vice President and Head of Pharmaceutical Development at AbbVie from 2013 to 2016. During his tenure at AbbVie, Dr. Brun oversaw a global organization with responsibilities for AbbVie’s entire portfolio of early and late-stage clinical pre-registration pipeline compounds as well as marketed compounds within oncology, neurology, immunology, renal, infectious disease, and women’s and men’s health therapeutic areas. Prior to joining AbbVie, Dr. Brun spent over 15 years at Abbott Laboratories, where he held positions of increasing leadership responsibility in drug development within the R&D organization. Dr. Brun is a member of the boards of directors of Axial Biotherapeutics, Inc. and Trishula Therapeutics, Inc., both private, clinical-stage biopharmaceutical companies, Jasper Therapeutics, Inc. (Nasdaq: JSPR) a biotechnology company focused on targeting mast cells and stem cells to treat chronic diseases and Forte Biosciences, Inc. (Nasdaq: FBRX) a preclinical-stage company focused on autoimmune diseases. Previously, Dr. Brun served as a Senior Advisor to the business development team at Horizon Therapeutics plc (Nasdaq: HZNP) from 2020 to 2023. Dr. Brun received his B.S. in Biochemistry from the University of Illinois at Urbana-Champaign and earned his M.D. from the Johns Hopkins University School of Medicine. He completed his residency in ophthalmology at the Massachusetts Eye and Ear Infirmary, Harvard Medical School. We believe Dr. Brun is qualified to serve as a member of our board of directors because of his scientific background and significant experience in clinical and research efforts.

Shawn Tomasello, MBA. Ms. Tomasello joined our Board of Directors in July 2023. She is currently Chief Executive Officer at CoRegen, Inc., a private company. Prior to her current role, Ms. Tomasello served as the Chief Commercial Officer of Kite Pharma, where she oversaw the global commercialization of Yescarta, from 2015 to 2018 including through its acquisition by Gilead for $11.9 billion in October 2017. She was previously Chief Commercial Officer at Pharmacyclics, where she led commercial and medical affairs activities for Imbruvica®, a first-in-class treatment for hematologic malignancies, from August 2014 until its acquisition by AbbVie for $21.0 billion in August 2015. Prior to Pharmacyclics, Ms. Tomasello served in leading commercial roles with multiple major pharmaceutical companies, including Celgene as President of the Americas Hematology and Oncology, where she led the company through five successful product launches encompassing 11 indications and played a critical role in acquisitions. At Genentech for 14 years prior, Ms. Tomasello was the National Director of Hematology for Rituxan. She currently serves on the board of directors of AlloVir, Inc. (Nasdaq: ALVR) since March 2022, 4D Molecular Therapeutics Inc. (Nasdaq: FDMT) since November 2020 and Centrexion Therapeutics Corp., a private, clinical-stage biopharmaceutical company, since 2017. She previously served as a board member of TCR2 Therapeutics Inc. (Nasdaq: TCRR) until June 2023, Urogen Pharma Ltd (Nasdaq: URGN) until 2022, Mesoblast, Ltd. (Nasdaq: MESO) until August 2022, Clementia Pharmaceuticals, Diplomat Pharmacy, Inc. until 2020, Abeona Therapeutics (Nasdaq: ABEO) until 2020, Principia Biopharma until 2020, and Gamida Cell Ltd. (Nasdaq: GMDA) until 2024, as well as several private boards. On such boards, she at various times has served and serves on the Compensation, Nominating and Corporate Governance, Compliance, and Transaction committees. Ms. Tomasello received her B.S. in Marketing from the University of Cincinnati and her M.B.A. from Murray State University in Kentucky. We believe Ms. Tomasello is qualified to serve as a member of our Board of Directors because of her experience serving in various commercial roles in the life sciences industry.

Catherine Bollard, MBChB, M.D. Dr. Bollard joined our board of directors in April 2019. She currently serves as Senior Vice President and Chief Research Officer and Director of the Center for Cancer and Immunology Research at the Children’s National Research Institute (CNRI). She is also a faculty member of the Division of the Blood and Marrow Transplantation at CNH. Since 2013, Dr. Bollard has served as a tenured Professor of Pediatrics and Microbiology, Immunology and Tropical Medicine at the George Washington University and is the Associate Center Director (ACD) for Translational Research and Innovation within the George Washington Cancer Center. Prior to her move in 2013, Dr. Bollard was Professor of Pediatrics, Medicine and

115

Immunology at Baylor College of Medicine. She is a past president of the International Society for Cell Therapy (ISCT), and she served on the Cellular, Tissues and Gene Therapy Advisory Committee of the FDA until 2019. Dr. Bollard chaired the Non-Hodgkin’s Lymphoma Committee of the Children’s Oncology Group from 2012 to 2020 and in 2021 became the President of the Foundation for the Accreditation of Cellular Therapy (FACT). Dr. Bollard was the scientific co-founder of Catamaran Bio, a company developing novel, off-the-shelf chimeric antigen receptor (CAR)-NK cell therapies designed to treat a broad range of cancers and served on its Scientific Advisory Board until 2024. Dr. Bollard was previously on the board of directors and subsequently the Scientific Advisory Board of Mana Therapeutics. She currently serves on the SAB of Minovia Tx Ltd and serves as Chair of the DSMB for SOBI. Bollard also serves on the board of directors for Alliance for Regenerative Medicine and a nonprofit organization she co-founded called Access4Kids. Dr. Bollard received her medical degree (MBChB) and her doctor of medicine (MD) from the University of Otago Medical School in New Zealand. We believe Dr. Bollard is qualified to serve as a member of our board of directors because of her scientific background and significant experience in clinical and translational research efforts.

Richard Henriques, MBA. Mr. Henriques joined our board of directors in February 2019. Since 2015, he has been a senior fellow at the Center for High Impact Philanthropy at the University of Pennsylvania, with a focus on impact investing. From 2010 to 2014, Mr. Henriques was the Chief Financial Officer of the Bill & Melinda Gates Foundation, where he was responsible for finance and accounting, financial planning and analysis, strategic planning, measurement and evaluation, program related investments and information technology. From 1981 to 2008, Mr. Henriques held positions at Merck & Co., Inc., including as Senior Vice President of Finance for Global Human Health, Vice President and Corporate Controller, and Principal Accounting Officer. Mr. Henriques serves on the boards of directors or trustees of the Bucks County Playhouse, International Vaccine Institute, Heritage Conservancy, Delaware Canal 21, Fisherman’s Mark and The Franklin Institute. Mr. Henriques served on the board of directors of Arbutus Biopharma Corporation (Nasdaq: ABUS) from December 2014 to February 2025. Mr. Henriques received his MBA from the Wharton School of the University of Pennsylvania and a BA from the University of Pennsylvania. We believe that Mr. Henriques is qualified to serve as a member of our board of directors because of his extensive corporate leadership experience and expertise in finance and investment management.

Family Relationships and Legal Proceedings

There are no family relationships between or among any of our directors or executive officers. Our executive officers are appointed by, and serve at the discretion of, our board of directors. The principal occupation and employment during the past five years of each of our directors was carried on, in each case except as specifically identified above, with a corporation or organization that is not a parent, subsidiary or other affiliate of us. There is no arrangement or understanding between any of our directors and any other person or persons pursuant to which he or she is to be selected as a director.

There are no material legal proceedings to which any of our directors, officers or affiliate, any owner of record or beneficially of more than five percent of any class of our voting securities, or any associate of any such director, officer, affiliate, or security holder is a party adverse to us or any of our subsidiaries or in which any such person has a material interest adverse to us or our subsidiary.

Board Committees

Our board of directors has established an audit committee, a compensation committee, and a nominating and corporate governance committee. Each of the audit committee, compensation committee, and nominating and corporate governance committee operates under a charter that satisfies the applicable standards of the SEC and Nasdaq. Our board of directors has also established a science and technology committee, an advisory committee of the board of directors which operates under a charter duly adopted by the board of directors. Each such committee reviews its respective charter at least annually. A current copy of the charter for each of the audit committee, compensation committee, nominating and corporate governance committee and science and technology committee is posted on the corporate governance section of our website, www.cabalettabio.com/investors/corporate-governance/governance-documents. From time to time, our board of directors may establish certain committees for scientific, business or other matters.

Audit Committee

Scott Brun, M.D., Richard Henriques, MBA and Mark Simon, MBA serve on the audit committee, which is chaired by Richard Henriques, MBA. Our board of directors has determined that each member of the audit committee is “independent” for audit committee purposes as that term is defined in the rules of the SEC and the applicable Nasdaq rules, and each has sufficient knowledge in financial and auditing matters to serve on the audit committee. Our board of directors has designated Mr. Henriques as an “audit

116

committee financial expert,” as defined under the applicable rules of the SEC. During the fiscal year ended December 31, 2024, the audit committee met seven times. The audit committee’s responsibilities include:

•

appointing, approving the compensation of, and assessing the independence of our independent registered public accounting firm;

•

pre-approving auditing and permissible non-audit services, and the terms of such services, to be provided by our independent registered public accounting firm;

•

reviewing the overall audit plan with our independent registered public accounting firm and members of management responsible for preparing our financial statements;

•

reviewing and discussing with management and our independent registered public accounting firm our annual and quarterly financial statements and related disclosures as well as critical accounting policies and practices used by us;

•

coordinating the oversight and reviewing the adequacy of our internal control over financial reporting;

•

establishing policies and procedures for the receipt and retention of accounting-related complaints and concerns;

•

recommending based upon the audit committee’s review and discussions with management and our independent registered public accounting firm whether our audited financial statements and our related disclosures under the “Management’s Discussion and Analysis” section shall be included in our 2024 Annual Report;

•

monitoring the integrity of our financial statements and our compliance with legal and regulatory requirements as they relate to our financial statements and accounting matters;

•

preparing the audit committee report required by SEC rules to be included in our annual proxy statement;

•

reviewing all related person transactions for potential conflict of interest situations and approving all such transactions;

•

reviewing quarterly earnings releases; and

•

discussing the Company’s risk assessment and management guidelines, including the Company’s major financial risk exposures, cybersecurity risks and the steps that the Company’s management has taken to monitor and control such exposures and risks.

All audit and non-audit services, other than de minimis non-audit services, to be provided to us by our independent registered public accounting firm must be approved in advance by our audit committee.

Compensation Committee

Richard Henriques, MBA, Mark Simon, MBA and Shawn Tomasello, MBA serve on the compensation committee, which is chaired by Mark Simon, MBA. Our board of directors has determined that each member of the compensation committee is “independent” as defined in the applicable Nasdaq rules. During the fiscal year ended December 31, 2024, the compensation committee met four times. The compensation committee’s responsibilities include:

•

annually reviewing and recommending to the board of directors corporate goals and objectives relevant to the compensation of our chief executive officer;

•

evaluating the performance of our chief executive officer in light of such corporate goals and objectives and based on such evaluation (i) recommending to the board of directors the cash compensation of our chief executive officer and (ii) reviewing and approving grants and awards to our chief executive officer under equity-based plans;

•

reviewing and approving the compensation of our other executive officers;

•

reviewing and establishing our overall management compensation, philosophy, and policy;

•

overseeing and administering our compensation and similar plans;

•

evaluating and assessing potential and current compensation advisors in accordance with the independence standards identified in the applicable Nasdaq rules;

•

reviewing and making recommendations to our board of directors about our policies and procedures for the grant of equity-based awards;

117

•

preparing the compensation committee report required by SEC rules, if and when required, to be included in our annual proxy statement;

•

reviewing and discussing annually with management our “Compensation Discussion and Analysis,” if and when required, to be included in our annual proxy statement; and

•

reviewing and approving the retention or termination of any consulting firm or outside advisor to assist in the evaluation of compensation matters.

Nominating and Corporate Governance Committee

Catherine Bollard, MBChB, M.D., Scott Brun, M.D., and Mark Simon, MBA, serve on the nominating and corporate governance committee, which is chaired by Scott Brun, M.D. Our board of directors has determined that each member of the nominating and corporate governance committee is “independent” as defined in the applicable Nasdaq rules. During the fiscal year ended December 31, 2024, the nominating and corporate governance committee met two times. The nominating and corporate governance committee’s responsibilities include:

•

developing and recommending to the board of directors criteria for board and committee membership;

•

establishing procedures for identifying and evaluating board of director candidates, including nominees recommended by stockholders;

•

reviewing the composition of the board of directors to ensure that it is composed of members containing the appropriate skills and expertise to advise us;

•

identifying individuals qualified to become members of the board of directors;

•

recommending to the board of directors the persons to be nominated for election as directors and to each of the board’s committees;

•

reviewing and discussing with the board of directors corporate succession plans for our chief executive officer and other key officers;

•

developing and recommending to the board of directors a code of business conduct and ethics and a set of corporate governance guidelines; and

•

overseeing the evaluation of our board of directors.

The nominating and corporate governance committee considers candidates for board of directors membership suggested by its members and the chief executive officer. Additionally, in selecting nominees for directors, the nominating and corporate governance committee will review candidates recommended by stockholders in the same manner and using the same general criteria as candidates recruited by the committee and/or recommended by our board of directors. Any stockholder who wishes to recommend a candidate for consideration by the committee as a nominee for director should follow the procedures described in our proxy statement under the heading “Stockholder Proposals.” The nominating and corporate governance committee will also consider whether to nominate any person proposed by a stockholder in accordance with the provisions of our bylaws relating to stockholder nominations as described in our proxy statement under the heading “Stockholder Proposals.”

Identifying and Evaluating Director Nominees. Our board of directors is responsible for filling vacancies on our board of directors and for nominating candidates for election by our stockholders each year in the class of directors whose term expires at the relevant annual meeting. The board of directors delegates the selection and nomination process to the nominating and corporate governance committee, with the expectation that other members of the board of directors, and of management, will be requested to take part in the process as appropriate.

Generally, the nominating and corporate governance committee identifies candidates for director nominees in consultation with management, through the recommendations submitted by stockholders or through such other methods as the nominating and corporate governance committee deems to be helpful to identify candidates. Once candidates have been identified, the nominating and corporate governance committee confirms that the candidates meet all of the minimum qualifications for director nominees established by the nominating and corporate governance committee. The nominating and corporate governance committee may gather information about the candidates through interviews, detailed questionnaires, comprehensive background checks or any other means that the nominating and corporate governance committee deems to be appropriate in the evaluation process. The nominating and corporate governance committee then meets as a group to discuss and evaluate the qualities and skills of each candidate, both

118

on an individual basis and taking into account the overall composition and needs of our board of directors. Based on the results of the evaluation process, the nominating and corporate governance committee recommends candidates for the board of directors’ approval to fill a vacancy or as director nominees for election to the board of directors by our stockholders each year in the class of directors whose term expires at the relevant annual meeting.

Science and Technology Committee

Catherine Bollard, MBChB, M.D., Scott Brun, M.D., and Shawn Tomasello, MBA, serve on the science and technology committee, which is chaired by Catherine Bollard, MBChB, M.D. The science and technology committee supports Board oversight of the Company’s research and development, manufacturing and supply activities, by providing a forum for review of strategic considerations and issues in such areas, as well as to evaluate relevant emerging technology and advances in the field. The science and technology committee was formed in July 2023 and held four meetings in during the fiscal year ended December 31, 2024.

Code of Business Conduct and Ethics

We have adopted a written code of business conduct and ethics that applies to our directors, officers and employees, including our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions. A current copy of the code is posted on the corporate governance section of our website, which is located at www.cabalettabio.com/investors/corporate-governance/governance-documents. If we make any substantive amendments to, or grant any waivers from, the code of business conduct and ethics for any officer or director, we will disclose the nature of such amendment or waiver on our website or in a current report on Form 8-K.

Insider Trading Policies and Procedures

We have adopted an insider trading policy that governs the purchase, sale, and/or other transactions of our securities by our directors, officers, employees and designated consultants that we believe is reasonably designed to promote compliance with applicable insider trading laws, rules and regulations, and listing standards applicable to us. A copy of our insider trading policy is filed as Exhibit 19.1 to this Annual Report on Form 10-K for the fiscal year ended December 31, 2024. In addition, with regard to trading in our own securities, it is our policy to comply with the federal securities laws and the applicable exchange listing requirements.

Our insider trading policy prohibits our directors, officers, employees and certain designated consultants, and their affiliated persons, from trading in company securities while in possession of material nonpublic information about our company. The policy also prohibits tipping (i.e., disclosing material nonpublic information about our company to others who may trade of the basis of that information). Under our insider trading policy, designated insiders may only trade in company securities at a time when they do not possess material nonpublic information about our company. We also require our directors, officers and certain other employees to receive approval before trading in company securities. Our insider trading policy also expressly prohibits short sales; purchases or sales of puts, calls, or other derivative securities or hedging transactions; using company securities as collateral in a margin account; or pledging company securities as collateral for a loan. Any waiver of the provisions of this policy requires the approval of our Audit Committee. To date, no such requests have been made or approved. We have also adopted an additional policy that governs adoption, modification and termination of written securities trading plans, known as Rule 10b5-1 plans, by our directors, executive officers and certain other persons. Our policy provides that all Rule 10b5-1 plans must comply with SEC rules applicable to the Rule 10b5-1 safe harbor and imposes additional requirements and limitations.

119

Item 11. Executive Compensation.

Our named executive officers for the year ended December 31, 2024 are:

•

Steven Nichtberger, M.D., our President and Chief Executive Officer;

•

Gwendolyn Binder, Ph.D., our President, Science and Technology; and

•

David J. Chang, M.D., M.P.H., our Chief Medical Officer.

2024 Summary Compensation Table

The following table presents the compensation awarded to, earned by or paid to each of our named executive officers for the years indicated. Dr. Nichtberger also serves as a member of our board of directors but does not receive any additional compensation for his service as a director.

(1) Amounts reflect the grant date fair value of option awards granted in 2024 and 2023 in accordance with the Financial Accounting Standards Board’s Accounting Standards Codification Topic 718, or ASC 718. Such grant date fair value does not take into account any estimated forfeitures related to service-vesting conditions. For information regarding assumptions underlying the valuation of equity awards, see Note 10 to our financial statements for the year ended December 31, 2024. These amounts do not correspond to the actual value that may be recognized by the named executive officers upon vesting of applicable awards.

(2) The amounts represent bonuses earned in 2024 and 2023 and paid in 2025 and 2024, respectively, pursuant to the Company’s cash incentive plan based on the factors described under “Non-Equity Incentive Plan Compensation” below.

(3) Amount includes reimbursements for life insurance premiums.

Narrative to 2024 Summary Compensation Table

Our board of directors and compensation committee review compensation annually for our chief executive officer and his direct reports. In setting executive base salaries and bonuses, and granting equity incentive awards, our board of directors considers compensation for comparable positions in the market, the historical compensation levels of our executives, individual performance as compared to our expectations and objectives, our desire to motivate our employees to achieve short-and long-term results that are in the best interests of our stockholders, and a long-term commitment to our company. We target a general competitive position, based on independent third-party benchmark analytics to inform the mix of compensation of base salary, bonus or long-term incentives.

Our board of directors has historically determined our executives’ compensation. Our compensation committee typically reviews and discusses management’s proposed compensation with the chief executive officer for all of his direct reports. Based on those discussions and its discretion, taking into account the factors noted above, the compensation committee determines the compensation for each executive officer other than the chief executive officer. Our board of directors discusses the compensation committee’s recommendations and ultimately approves the compensation of our chief executive officer without the chief executive officer and chief financial officer present. In 2024, the compensation committee continued to retain the services of Radford, an AON Hewitt company, as its external compensation consultant and the board of directors and the compensation committee considered Radford’s input on certain compensation matters as they deemed appropriate.

Annual base salary

Each named executive officer’s base salary is a fixed component of annual compensation for performing specific duties and functions, and has been established by our board of directors taking into account each individual’s role, responsibilities, skills, and

120

experience. Base salaries for our named executive officers are reviewed annually by our compensation committee, typically in connection with our annual performance review process, and adjusted from time to time, based on the recommendation of the compensation committee, to realign salaries with market levels after taking into account individual responsibilities, performance, and experience. The base salary of each named executive officer in 2024 is noted below:

Non-Equity Incentive Plan Compensation

Annual cash awards are determined based on company performance, which is assessed based on predetermined annual objectives, and on individual performance. When determining the individual component of our annual incentive awards, the compensation committee considers each executive’s contributions to the company’s strategic achievements and financial and operational performance. In addition, the compensation committee considers how each executive demonstrates Cabaletta behaviors.

Each of our named executive officers was eligible to receive a bonus with respect to 2024 as a percentage of base salary listed below, modified by company and individual performance.

Name 2024 Target Bonus Rate(% of base salary)

Steven Nichtberger, M.D. 55 %

Gwendolyn K. Binder, Ph.D. 40 %

David J. Chang, M.D., M.P.H. 40 %

Company performance was assessed as achievement of 2024 company objectives, including certain clinical development, business development and financial and operational goals and development of a strong team culture. As a result, the compensation committee recommended and our board of directors approved 2024 company achievement at 108%.

The compensation committee recommended (and/or approved) and the board of directors approved (as applicable, in the instance of the chief executive officer), a further adjustment of bonuses based on the individual achievement of each of the named executive officers, as noted below:

Name IndividualAchievement (%)

Steven Nichtberger, M.D. 114 %

Gwendolyn K. Binder, Ph.D. 115 %

David J. Chang, M.D., M.P.H. 125 %

Long-term equity incentives

Our equity grant program is intended to align the interests of our named executive officers with those of our stockholders and to motivate them to make important contributions to our performance. In 2024, we granted stock options to each of our named executive officers, as reflected in the “Outstanding Equity Awards at 2024 Fiscal Year End Table” below.

Employment arrangements with our named executive officers

In October 2019, we entered into amended and restated employment agreements with each of our named executive officers. Each of our named executive officers is employed at will.

Steven Nichtberger, M.D.

Under his amended and restated employment agreement, Dr. Nichtberger is entitled to an annual base salary, which is subject to review and redetermination by our board of directors or our compensation committee, and he is eligible to receive an annual bonus determined by our board of directors or the compensation committee (subject to the terms of any applicable incentive compensation plan that may be in effect from time to time), with a target amount calculated as a percentage of his annual base salary. Dr.

121

Nichtberger is also eligible to participate in the employee benefit plans available to our employees, subject to the terms of those plans, and is reimbursed for his existing, personal life insurance policy premiums.

Dr. Nichtberger’s employment agreement provides that, in the event that his employment is terminated by us without “cause” or by him for “good reason,” then subject to the execution and effectiveness of a separation agreement and release and compliance with his continuing obligations, he will be entitled to receive (i) an amount equal to (x) 12 months of base salary payable on our normal payroll cycle if such termination occurs outside of the period commencing 60 days before and ending 12 months after the occurrence of the first event constituting a “change in control”, or the Change in Control Period, or (y) 1.5 times the sum of his base salary plus his target bonus for the then-current year payable on our or our successor’s normal payroll cycle over 18 months if such termination occurs within Change in Control Period; (ii) payment of the monthly employer COBRA premium for the same level of group health coverage as in effect for Dr. Nichtberger on the date of termination for up to (x) 12 months if such termination occurs outside of the Change in Control Period, and (y) 18 months if such termination occurs within the Change in Control Period; and (iii) full acceleration of all stock options and other stock-based awards held by Dr. Nichtberger if such termination occurs within the Change in Control Period. In addition to standard good reason triggers, Dr. Nichtberger may elect to resign for good reason if within six months following the appointment of a chairperson of the board of directors, Dr. Nichtberger provides written notice of his reasonable dissatisfaction with such chairperson and the board fails to designate a new chairperson within 30 days of such notice. In the event of such a resignation for good reason outside of the Change in Control Period, subject to the execution and effectiveness of a separation agreement and release and compliance with his continuing obligations, in addition to the severance benefits described above, all stock options and other stock-based awards held by Dr. Nichtberger will accelerate and become fully exercisable or nonforfeitable.

The payments and benefits provided to Dr. Nichtberger under his employment agreement in connection with a sale event may not be eligible for a federal income tax deduction for the company pursuant to Section 280G of the Code. These payments and benefits also may be subject to an excise tax under Section 4999 of the Code. If the payments or benefits payable to Dr. Nichtberger in connection with a sale event would be subject to the excise tax on golden parachutes imposed under Section 4999 of the Code, then those payments or benefits will be reduced if such reduction would result in a higher net after tax benefit to Dr. Nichtberger.

In addition, Dr. Nichtberger has entered into a non-competition, non-solicitation, confidentiality and assignment agreement with us that contains, among other things, non-competition and non-solicitation provisions that apply during the term of Dr. Nichtberger’s employment and for 12 months thereafter.

Gwendolyn K. Binder, Ph.D.

Under her amended and restated employment agreement, Dr. Binder is entitled to an annual base salary, which is subject to review and redetermination by our board of directors or our compensation committee, and she is eligible to earn an annual bonus with a target amount calculated as a percentage of her base salary. Dr. Binder is also eligible to participate in the employee benefit plans available to our employees, subject to the terms of those plans.

Dr. Binder’s employment agreement provides that, in the event that her employment is terminated by us without “cause” or by her for “good reason,” then subject to the execution and effectiveness of a separation agreement and release and compliance with her continuing obligations, she will be entitled to receive (i) an amount equal to (x) nine months of base salary payable on our normal payroll cycle if such termination occurs outside of the Change in Control Period or (y) a lump sum in cash in the amount of 1.0 times the sum of her base salary plus her target bonus for the then-current year payable on our or our successor’s normal payroll cycle over 12 months if such termination is occurs within the Change in Control Period; (ii) payment of the monthly employer COBRA premium for the same level of group health coverage as in effect for Dr. Binder on the date of termination up to (x) nine months if such termination occurs outside of the Change in Control Period, and (y) 12 months if such termination occurs within the Change in Control Period; and (iii) full acceleration of all stock options and other stock-based awards subject to time-based vesting held by Dr. Binder if such termination occurs within the Change in Control Period.

The payments and benefits provided to Dr. Binder under her employment agreement in connection with a sale event may not be eligible for a federal income tax deduction for the company pursuant to Section 280G of the Code. These payments and benefits also may be subject to an excise tax under Section 4999 of the Code. If the payments or benefits payable to Dr. Binder in connection with a sale event would be subject to the excise tax on golden parachutes imposed under Section 4999 of the Code, then those payments or benefits will be reduced if such reduction would result in a higher net after-tax benefit to such officer.

In addition, Dr. Binder has entered into a non-competition, non-solicitation, confidentiality and assignment agreement with us that contains, among other things, non-competition and non-solicitation provisions that apply during the term of Dr. Binder’s employment and for 12 months thereafter.

122

David J. Chang, M.D., M.P.H.

Under his amended and restated employment agreement, Dr. Chang is entitled to an annual base salary, which is subject to review and redetermination by our board of directors or our compensation committee, and he is eligible to earn an annual bonus with a target amount calculated as a percentage of his base salary. Dr. Chang is also eligible to participate in the employee benefit plans available to our employees, subject to the terms of those plans.

Dr. Chang’s employment agreement provides that, in the event that his employment is terminated by us without “cause” or by him for “good reason,” then subject to the execution and effectiveness of a separation agreement and release and compliance with his continuing obligations, he will be entitled to receive (i) an amount equal to (x) nine months of base salary payable on our normal payroll cycle if such termination occurs outside of the Change in Control Period or (y) a lump sum in cash in the amount of 1.0 times the sum of his base salary plus his target bonus for the then-current year payable on our or our successor’s normal payroll cycle over 12 months if such termination occurs within the Change in Control Period; (ii) payment of the monthly employer COBRA premium for the same level of group health coverage as in effect for Dr. Chang on the date of termination up to (x) nine months if such termination occurs outside of the Change in Control Period, and (y) 12 months if such termination occurs outside of the Change in Control Period; and (iii) full acceleration of all stock options and other stock-based awards subject to time-based vesting held by Dr. Chang if such termination occurs within the Change in Control Period.

The payments and benefits provided to Dr. Chang under his employment agreement in connection with a sale event may not be eligible for a federal income tax deduction for the company pursuant to Section 280G of the Code. These payments and benefits also may be subject to an excise tax under Section 4999 of the Code. If the payments or benefits payable to Dr. Chang in connection with a sale event would be subject to the excise tax on golden parachutes imposed under Section 4999 of the Code, then those payments or benefits will be reduced if such reduction would result in a higher net after-tax benefit to such officer.

In addition, Dr. Chang has entered into a non-competition, non-solicitation, confidentiality and assignment agreement with us that contains, among other things, non-competition and non-solicitation provisions that apply during the term of Dr. Chang’s employment and for 12 months thereafter.

123

Outstanding Equity Awards at 2024 Fiscal Year End Table

The following table presents information regarding all outstanding stock awards and stock options held by each of our named executive officers as of December 31, 2024.

Option awards Stock awards

(1) These options vest over four years, with 25% vesting on October 11, 2019, and the remaining shares vesting in 36 equal monthly installments thereafter, subject to a continued service relationship with us.

(2) These options vest over four years, with 25% vesting on October 24, 2020, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(3) These options vest over four years, with 25% vesting on March 1, 2021, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(4) These options vest over four years, with 25% vesting on October 11, 2019 and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(5) These options vest over four years, with 25% vesting on August 22, 2020, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(6) These options vest over four years, with 25% vesting on June 17, 2020, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(7) These options vest over four years, with 25% vesting on March 1, 2022, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(8) These options vest over four years, with 25% vesting on January 18, 2023, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(9) These options vest over four years, with 25% vesting on January 18, 2024, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(10) These options vest over four years, with 25% vesting on March 1, 2025, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

124

Additional Narrative Disclosure

401(k) Savings Plan. We participate in a retirement savings plan, or 401(k) plan, that is intended to qualify for favorable tax treatment under Section 401(a) of the Code, and contains a cash or deferred feature that is intended to meet the requirements of Section 401(k) of the Code. U.S. employees who are at least 21 years of age are generally eligible to participate in the 401(k) plan, subject to certain criteria. Participants may make pre-tax and certain after-tax (Roth) salary deferral contributions to the plan from their eligible earnings up to the statutorily prescribed annual limit under the Code. Participants who are 50 years of age or older may contribute additional amounts based on the statutory limits for catch-up contributions. Participant contributions are held in trust as required by law. An employee’s interest in his or her salary deferral contributions is 100% vested when contributed. We have the ability to make discretionary contributions under the plan and all eligible employees will receive a Safe Harbor matching contribution up to 4% of eligible pay for the 2024 plan year.

Health and Welfare Benefits. All of our full-time employees, including our executive officers are eligible to participate in certain medical, disability and life insurance benefit programs offered by us. We pay the premiums for term life insurance and long-term disability for all of our employees, including our executive officers. We also provide all employees, including executive officers, with a flexible spending account plan and paid time off benefits including, vacation, sick time and holidays. We do not sponsor any qualified or non-qualified defined benefit plans for any of our employees or executives.

Compensation Risk Assessment

We believe that although a portion of the compensation provided to our executive officers and other employees is performance-based, our executive compensation program does not encourage excessive or unnecessary risk taking. Our compensation programs are designed to encourage our executive officers and other employees to remain focused on both short-term and long-term strategic goals, in particular in connection with our pay-for-performance compensation philosophy. As a result, we do not believe that our compensation programs are reasonably likely to have a material adverse effect on us.

Policy on Trading, Pledging and Hedging of Company Stock

Certain transactions in our securities (such as purchases and sales of publicly traded put and call options, and short sales) create a heightened compliance risk or could create the appearance of misalignment between management and stockholders. In addition, securities held in a margin account or pledged as collateral may be sold without consent if the owner fails to meet a margin call or defaults on the loan, thus creating the risk that a sale may occur at a time when an officer or director is aware of material, non-public information or otherwise is not permitted to trade in Company securities. Our insider trading policy expressly prohibits short sales and derivative transactions of our stock by our executive officers, directors, employees and certain designated consultants and contractors, including short sales of our securities. Our insider trading policy expressly prohibits, without the advance approval of our audit committee, purchases or sales of puts, calls, or other derivative securities of the company or any derivative securities that provide the economic equivalent of ownership.

Compensation Recovery Policy (Clawback Policy)

On September 12, 2023, we adopted a Compensation Recovery Policy, or the Clawback Policy, in compliance with the requirements of the Dodd-Frank Act, final SEC rules and applicable Nasdaq listing standards (the “final clawback rules”), which covers our current and former executive officers, including all of our named executive officers. Under the Clawback Policy, in the event that we are required to prepare a restatement of our previously issued financial statements due to our material noncompliance with any financial reporting requirement under securities laws, we are required to recover (subject to certain limited exceptions described in the Clawback Policy and permitted under the final clawback rules) any cash or equity incentive-based compensation received by any current or former executive officer after the effective date of the Clawback Policy and in the three years prior to the date we are required to restate our financial statements that is in excess of the amount that would have been received based on the restated financial statements.

Compensation Committee Interlocks and Insider Participation

Each of Richard Henriques, Mark Simon and Shawn Tomasello, served on the compensation committee during fiscal year 2024. No member of the compensation committee has ever been an officer or employee of the Company. None of our executive officers serve, or have served during the last fiscal year, as a member of the board of directors, compensation committee, or other

125

board committee performing equivalent functions of any other entity that has one or more executive officers serving as one of our directors or on our compensation committee.

Policy on the Timing of Awards of Options and Other Option-Like Instruments

Our compensation committee has generally granted annual equity awards, including stock option grants to our named executive officers, in the first quarter of each fiscal year, specifically early March. In addition, new hires receive stock option grants at the time of their hiring. Eligible employees, including our named executive officers, may voluntarily enroll in our Employee Stock Purchase Plan and receive an option to purchase shares at a discount using payroll deductions accumulated during the prior six months, with purchase dates occurring in May and November. During 2024, our compensation committee did not take into account any material nonpublic information when determining the timing and terms of equity incentive awards, and we did not time the disclosure of material nonpublic information for the purpose of affecting the value of executive compensation. During 2024, we did not grant stock options to our named executive officers during any period beginning four business days before and ending one business day after the filing or furnishing of a Form 10-Q, 10-K or 8-K that discloses material nonpublic information.

Please see Item 10 for details regarding corporate governance, including the composition of our compensation committee, as required by Regulation S-K 407(e)(4) and (e)(5).

Director Compensation

The following table presents the total compensation for each person who served as a non-employee member of our board of directors and received compensation for such service during the fiscal year ended December 31, 2024. Other than as set forth in the table and described more fully below, we did not pay any compensation, make any equity awards or non-equity awards to, or pay any other compensation to any of the non-employee members of our board of directors in 2024. We reimburse members of our board of directors for reasonable travel expenses. Dr. Nichtberger, our Chief Executive Officer and President, did not receive any compensation for his service as a member and Chairman of our board of directors in 2024. Dr. Nichtberger’s compensation for service as an employee for fiscal years 2024 and 2023 is presented in “Executive Compensation—2024 Summary Compensation Table.”

(1) Amount shown reflects the grant date fair value of an option award granted during 2024. The grant date fair value was computed in accordance with Financial Accounting Standards Board Accounting Standards Codification Topic 718, Compensation—Stock Compensation, or FASB ASC Topic 718, disregarding the effect of estimated forfeitures related to service-based vesting. See Note 10 to the financial statements in our 2024 Annual Report on Form 10-K regarding assumptions we made in determining the fair value of option awards.

(2) As of December 31, 2024, the aggregate number of shares subject to option awards held by our non-employee directors were: Dr. Bollard: 134,428; Dr. Brun: 110,000; Mr. Henriques: 134,428; Mr. Simon: 134,428 and Ms. Tomasello 66,000. As of December 31, 2024, the aggregate number of unvested shares outstanding held by our non-employee directors were: Dr. Bollard: 22,000; Dr. Brun: 22,000; Mr. Henriques: 22,000; Mr. Simon: 22,000 and Ms. Tomasello 47,667.

Amended and Restated Non-Employee Director Compensation Policy

Under our director compensation policy, we pay our non-employee directors a cash retainer for service on the board of directors and for service on each committee on which the director is a member. The chairman of each committee receives a higher retainer for such service. These fees are payable in arrears in four equal quarterly installments on the last day of each quarter, providedthat the amount of such payment is prorated for any portion of such quarter that the director is not serving on our board of directors.

The fees paid to non-employee directors for service on the board of directors and for service on each committee of the board of directors on which the director is a member for 2024 are as follows:

126

Member AnnualRetainer ($) Chairperson AnnualRetainer ($)

Board of Directors 40,000 —

Nominating and Corporate Governance Committee 5,000 10,000

In February 2025, we amended our director compensation policy. Accordingly, the fees paid to non-employee directors for service on the board of directors and for service on each committee of the board of directors on which the director is a member for 2025 are as follows:

Member AnnualRetainer ($) Chairperson AnnualRetainer ($)

Board of Directors 40,000 —

Nominating and Corporate Governance Committee 5,000 10,000

We also reimburse our non-employee directors for reasonable out-of-pocket expenses incurred in connection with attending our board of director and committee meetings.

In addition, each new non-employee director elected to our board of directors will be granted an initial, one-time award of a stock option to purchase 44,000 shares, which shall vest in equal quarterly installments over a three-year period from the date of vesting commencement, subject to continued service as a director through each such vesting date. In addition, on the date of each annual meeting of stockholders of our company, each non-employee director will receive an annual stock option award of 22,000 shares, which shall vest in full upon the earlier to occur of the first anniversary of the date of grant or the date of the next annual meeting provided, however, that all vesting shall cease if the director resigns from the board of directors or otherwise ceases to serve as a director, unless the board of directors determines that the circumstances warrant continuation of vesting.

This program is intended to provide a total compensation package that enables us to attract and retain qualified and experienced individuals to serve as directors and to align our directors’ interests with those of our stockholders.

127

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.

Equity Compensation Plan Information

The following table provides information as of December 31, 2024 regarding shares of common stock that may be issued under our equity compensation plans, consisting of the 2018 Plan, the 2019 Plan and the 2019 Employee Stock Purchase Plan, or the ESPP. We have no equity compensation plans that were not approved by security holders.

Equity compensation plans not approved by security holders — — —

(1) Consists of our 2019 Stock Option and Incentive Plan, 2018 Stock Option and Grant Plan, and 2019 Employee Stock Purchase Plan. Following our initial public offering, we have not and will not grant any awards under our 2018 Stock Option and Grant Plan, but all outstanding awards under the 2018 Stock Option and Grant Plan will continue to be governed by their existing terms. The shares of common stock underlying any awards granted under the 2018 Stock Option and Grant Plan or 2019 Stock Option and Incentive Plan that are forfeited, canceled, reacquired by us prior to vesting, satisfied without the issuance of stock, or otherwise terminated (other than by exercise) and the shares of common stock that are withheld upon exercise of a stock option or settlement of such award to cover the exercise price or tax withholding will be added to the shares of common stock available for issuance under the 2019 Stock Option and Incentive Plan.

(2) Includes 11,231,148 shares of common stock issuable upon the exercise of outstanding options, of which 1,235,458 are subject to our 2018 Stock Option and Grant Plan and 9,995,690 are subject to our 2019 Stock Option and Incentive Plan.

(3) As of December 31, 2024, there were 1,379,305 shares available for grant under the 2019 Stock Option and Incentive Plan and 314,259 shares available for grants under the 2019 Employee Stock Purchase Plan.

(4) The 2019 Stock Option and Incentive Plan provides that the number of shares reserved and available for issuance under the plan will automatically increase each January 1, beginning on January 1, 2020, by 4% of the outstanding number of shares of our common stock on the immediately preceding December 31. The 2019 Employee Stock Purchase Plan provides that the number of shares reserved and available for issuance will automatically increase each January 1, beginning on January 1, 2020, through January 1, 2029, by the least of 234,229 shares of our common stock, 1% of the outstanding number of shares of our common stock on the immediately preceding December 31, or such lesser number of shares as determined by our compensation committee.

Security Ownership of Certain Beneficial Owners and Management

The following table sets forth information, to the extent known by us or ascertainable from public filings, with respect to the beneficial ownership of our common stock as of March 7, 2025 by:

•

each of our directors;

•

each of our named executive officers;

•

all of our directors and executive officers as a group; and

•

each person, or group of affiliated persons, who is known by us to beneficially own greater-than-5.0% of our common stock.

The column entitled “Shares Beneficially Owned” is based on a total of 50,743,101 shares of our common stock outstanding as of March 7, 2025.

Beneficial ownership is determined in accordance with the rules and regulations of the SEC and includes voting or investment power with respect to our common stock. Shares of our common stock subject to options or warrants that are currently exercisable or exercisable within 60 days of March 7, 2025 are considered outstanding and beneficially owned by the person holding the options or warrants for the purpose of calculating the percentage ownership of that person but not for the purpose of calculating the percentage ownership of any other person. Except as otherwise noted, the persons and entities in this table have sole voting and investing power with respect to all of the shares of our common stock beneficially owned by them, subject to community property

128

laws, where applicable. Except as otherwise indicated in the table below, addresses of named beneficial owners are in care of Cabaletta Bio, Inc., 2929 Arch Street, Suite 600, Philadelphia, Pennsylvania 19104.

Shares beneficially owned

Name and address of beneficial owner(1) Number Percentage

> 5% Stockholders:

Entities Affiliated with Adage Capital Partners, L.P.(3) 3,634,475 7.2%

T. Rowe Price Investment Management, Inc.(4) 3,673,724 7.2%

Entities affiliated with Prudential Financial, Inc.(5) 2,798,863 5.5%

Bain Capital Life Sciences Opportunities III, LP(6) 2,760,888 5.4%

Named Executive Officers and Directors:

* Represents beneficial ownership of less than one percent.

(1) Unless otherwise indicated, the address for each beneficial owner is c/o Cabaletta Bio, Inc., 2929 Arch Street, Suite 600, Philadelphia, Pennsylvania 19104.

(2) The information reported is based on information in a Schedule 13G/A, as filed by BlackRock, Inc. with the SEC on February 5, 2025. In that filing, BlackRock, Inc. reports sole voting power with respect to 3,329,097 shares of common stock and sole dispositive power with respect to 3,397,260 shares, and lists its address as 50 Hudson Yards, New York, New York 10001.

(3) The information is based on a Schedule 13G/A filed with the SEC on November 12, 2024. Consists of 3,036,645 shares of common stock and 597,830 shares of common stock issuable upon the exercise of pre-funded warrants held by Adage Capital Partners, L.P., or ACP. Adage Capital Partners GP, L.L.C., or ACPGP, is the general partner of ACP. Adage Capital Management, L.P., or ACM, is the investment manager of ACP. Adage Capital Advisors, L.L.C., or ACA, is managing member of ACPGP.Adage Capital Partners LLC, or ACPLLC, is the general partner of ACM, with respect to the shares of voting common stock directly held by ACP. Robert Atchinson and Phillip Gross are managing members of ACA and ACPGP and are general partners of ACP. Each of ACP, ACPGP, ACA, ACM, Robert Atchinson, and Phillip Gross have shared voting and dispositive power over all of the shares. The ability of the Adage entities to exercise their pre-funded warrants is subject to a beneficial ownership limitation, which prevents the Adage entities from exercising any portion of the warrants to the extent such exercise would result in the Adage entities exceeding a certain percentage of the total number of issued and outstanding shares of our common stock following such exercise. The address for Adage Capital Partners, L.P. is 200 Clarendon Street, 52nd Floor, Boston, Massachusetts 02116.

(4) The information reported is based on information in a Schedule 13G/A, as filed by T. Rowe Price Investment Management, Inc. (Price Investment Management) with the SEC on November 14, 2024. In that filing, T. Rowe Price Investment Management, Inc. (Price Investment Management) reports sole voting power with respect to 3,666,024 shares of common stock and sole dispositive power with respect to 3,673,724 shares, and lists its address as 101 E. Pratt Street, Baltimore, MD 21201.

(5) The information reported is based on information in a Schedule 13G/A, as filed by Prudential Financial, Inc. with the SEC on December 5, 2024. In that filing, Prudential Financial, Inc. reports shared voting and dispositive power over (i) 2,796,053 shares of our common stock, being 2,512,053 shares held through its subsidiary Jennison Associates LLC and 284,000 shares held through its subsidiary PGIM, Inc., and (ii) sole voting and dispositive power over 2,810 shares of our common stock held through its subsidiary PGIM Quantitative Solutions LLC. The address provided for Prudential Financial, Inc. is 751 Broad Street, New Jersey 07102.

(6) The information reported is based on information in a Schedule 13G, as filed by Bain Capital Life Sciences Opportunities III, LP with the SEC on August 22, 2024. In that filing, Bain Capital Life Sciences Opportunities III, LP reports shared voting power and shared dispositive power with respect to 2,760,888 shares of common stock. Bain Capital Life Sciences Investors, LLC, or BCLSI, is the manager of Bain Capital Life Sciences III General Partner, LLC, which is the general partner of Bain Capital Life Sciences Fund III, L.P., which is the sole member of Bain Capital Life Sciences Opportunities III GP, LLC, which is the general partner of Bain Capital Life Sciences Opportunities III, LP. As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by Bain Capital Life Sciences Opportunities III, LP. The address of BCLSI is 200 Clarendon Street, Boston, MA 02116.

129

(7) The information reported is based on information in a Schedule 13G/A, as filed by The Vanguard Group with the SEC on November 12, 2024. In that filing, The Vanguard Group reports shared voting power with respect to 31,135 shares of common stock, sole dispositive power with respect to 2,500,994 shares and shared dispositive power with respect to 52,716 shares, and lists its address as 100 Vanguard Blvd., Malvern, PA 19355.

(8) Consists of (i) 986,483 shares of common stock held by Dr. Nichtberger, (ii) 363,000 shares of common stock held by the 2017 Nichtberger Family Trust, or the Trust Shares, and (iii) 1,177,867 shares of common stock underlying options exercisable within 60 days of March 7, 2025. Dr. Nichtberger may be deemed to beneficially own the Trust Shares. Dr. Nichtberger disclaims beneficial ownership of the Trust Shares and this shall not be deemed an admission that he is the beneficial owner of the Trust Shares.

(9) Consists of (i) 20,000 shares of common stock held and (ii) 583,831shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(10) Consists of 612,846 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(11) Consists of (i) 1,000 shares of common stock held and (ii) 112,428 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(12) Consists of 88,000 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(13) Consists of 112,428 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(14) Consists of (i) 143,144 shares of common stock held and (ii) 112,428 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(15) Consists of 25,667 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(16) See notes (7) through (14); also includes an aggregate of (i) 50,000 shares of common stock and (ii) 1,066,947 shares of common stock subject to options exercisable within 60 days of March 7, 2025 held by Anup Marda, our Chief Financial Officer, Michael Gerard, our General Counsel and Secretary, and Arun Das, M.D., our Chief Business Officer.

130

Item 13. Certain Relationships and Related Transactions, and Director Independence.

Certain Relationships and Transactions

Other than the compensation agreements and other arrangements described under “Executive compensation” and “Director compensation” in this Annual Report on Form 10-K for the fiscal year ended December 31, 2024 and the transactions described below, since January 1, 2023, there has not been and there is not currently proposed, any transaction or series of similar transactions to which we were, or will be, a party in which the amount involved exceeded, or will exceed, $120,000 (or, if less, 1% of the average of our total assets amounts at December 31, 2023 and 2024) and in which any director, executive officer, holder of five percent or more of any class of our capital stock or any member of the immediate family of, or entities affiliated with, any of the foregoing persons, had, or will have, a direct or indirect material interest.

May 2023 Offering

In May 2023, we issued 8,337,500 shares of our common stock at a price of $12.00 per share in connection with an underwritten public offering. Certain existing holders of five percent or more of a class of our capital stock participated in the transaction, as evidenced by the table below.

Limitation of Liability and Indemnification of Officers and Directors

Our certificate of incorporation contains provisions that limit the liability of our directors for monetary damages to the fullest extent permitted by Delaware law. Consequently, our directors will not be personally liable to us or our stockholders for monetary damages for any breach of fiduciary duties as directors, except liability for the following:

•

any breach of their duty of loyalty to our company or our stockholders;

•

any act or omission not in good faith or that involves intentional misconduct or a knowing violation of law;

•

unlawful payments of dividends or unlawful stock repurchases or redemptions as provided in Section 174 of the Delaware General Corporation Law; or

•

any transaction from which they derived an improper personal benefit.

Any amendment to, or repeal of, these provisions will not eliminate or reduce the effect of these provisions in respect of any act, omission or claim that occurred or arose prior to that amendment or repeal. If the Delaware General Corporation Law is amended to provide for further limitations on the personal liability of directors of corporations, then the personal liability of our directors will be further limited to the greatest extent permitted by the Delaware General Corporation Law.

In addition, we adopted bylaws which provide that we will indemnify, to the fullest extent permitted by law, any person who is or was a party or is threatened to be made a party to any action, suit or proceeding by reason of the fact that he or she is or was one of our directors or officers or is or was serving at our request as a director or officer of another corporation, partnership, joint venture, trust, or other enterprise. Our bylaws provide that we may indemnify to the fullest extent permitted by law any person who is or was a party or is threatened to be made a party to any action, suit, or proceeding by reason of the fact that he or she is or was one of our employees or agents or is or was serving at our request as an employee or agent of another corporation, partnership, joint venture, trust or other enterprise. Our bylaws also provide that we must advance expenses incurred by or on behalf of a director or officer in advance of the final disposition of any action or proceeding, subject to very limited exceptions.

We have entered into and in the future plan to enter into agreements to indemnify our directors and executive officers. These agreements, among other things, require us to indemnify these individuals for certain expenses (including attorneys’ fees), judgments, fines and settlement amounts reasonably incurred by such person in any action or proceeding, including any action by or in our right, on account of any services undertaken by such person on behalf of our company or that person’s status as a member of our board of directors to the maximum extent allowed under Delaware law.

131

Related person transaction policy

Our board of directors adopted a written related person transaction policy providing that transactions with our directors, officers and holders of five percent or more of our voting securities and their affiliates, each a related person, must be approved by our audit committee. This policy became effective on October 29, 2019, the date our registration statement for our initial public offering became effective. Pursuant to this policy, the audit committee has the primary responsibility for reviewing and approving or disapproving “related person transactions,” which are transactions between us and related persons in which the aggregate amount involved exceeds or may be expected to exceed $120,000 and in which a related person has or will have a direct or indirect material interest. For purposes of this policy, a related person is defined as a director, executive officer, nominee for director, or greater than 5% beneficial owner of our common stock, in each case since the beginning of the most recently completed year, and their immediate family members.

As appropriate for the circumstances, the audit committee will review and consider:

•

the related person’s interest in the related person transaction;

•

the approximate dollar amount involved in the related person transaction;

•

the approximate dollar amount of the related person’s interest in the transaction without regard to the amount of any profit or loss;

•

whether the transaction was undertaken in the ordinary course of our business;

•

whether the terms of the transaction are no less favorable to us than terms that could have been reached with an unrelated third party;

•

the purpose of, and the potential benefits to us of, the related-party transaction; and

•

any other information regarding the related-party transaction or the related person in the context of the proposed transaction that would be material to investors in light of the circumstances of the particular transaction.

Director Independence

Applicable Nasdaq rules require a majority of a listed company’s board of directors to be comprised of independent directors within one year of listing. In addition, the Nasdaq rules require that, subject to specified exceptions, each member of a listed company’s audit, compensation and nominating and corporate governance committees be independent and that audit committee members also satisfy independence criteria set forth in Rule 10A-3 under the Exchange Act and that compensation committee members satisfy independence criteria set forth in Rule 10C-1 under the Exchange Act. Under applicable Nasdaq rules, a director will only qualify as an “independent director” if, in the opinion of the listed company’s board of directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In order to be considered independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the board of directors, or any other board committee, accept, directly or indirectly, any consulting, advisory, or other compensatory fee from the listed company or any of its subsidiaries or otherwise be an affiliated person of the listed company or any of its subsidiaries. In addition, in affirmatively determining the independence of any director who will serve on a company’s compensation committee, Rule 10C-1 under the Exchange Act requires that a company’s board of directors must consider all factors specifically relevant to determining whether a director has a relationship to such company which is material to that director’s ability to be independent from management in connection with the duties of a compensation committee member, including: the source of compensation to the director, including any consulting, advisory or other compensatory fee paid by such company to the director, and whether the director is affiliated with the company or any of its subsidiaries or affiliates.

Our board of directors has determined that all members of the board of directors, except Dr. Nichtberger are independent directors, including for purposes of the rules of Nasdaq and the SEC. In making such independence determination, our board of directors considered the relationships that each non-employee director has with us and all other facts and circumstances that our board of directors deemed relevant in determining their independence, including the beneficial ownership of our capital stock by each non-employee director. In considering the independence of the directors listed above, our board of directors considered the association of our directors with the holders of more than 5% of our common stock. There are no family relationships among any of our directors or executive officers. Dr. Nichtberger is not an independent director under these rules because he is an executive officer of the Company.

132

Item 14. Principal Accountant Fees and Services.

Our independent public accounting firm is Ernst & Young, Philadelphia, PA, PCAOB Auditor ID 42.

Cabaletta incurred the following fees from Ernst & Young for the audit of the financial statements and for other services provided during the years ended December 31, 2024 and 2023.

Audit-Related fees(2) — —

All other fees(4) — —

(1) Audit fees consist of fees for the audit of our annual financial statements, the review of our interim financial statements included in our quarterly reports on Form 10-Q, comfort letters and consents.

(2) Audit-related fees consist of services that are reasonably related to the performance of the audit or review of our financial statements. There were no such fees incurred in 2024 or 2023.

(3) Tax Fees consist of fees for tax compliance, advice and tax services.

(4) There were no other fees incurred in 2024 or 2023.

Audit Committee Pre-approval Policy and Procedures

Our audit committee has adopted policies and procedures relating to the approval of all audit and non-audit services that are to be performed by our independent registered public accounting firm. This policy provides that we will not engage our independent registered public accounting firm to render audit or non-audit services unless the service is specifically approved in advance by our audit committee or the engagement is entered into pursuant to the pre-approval procedure described below.

From time to time, our audit committee may pre-approve specified types of services that are expected to be provided to us by our independent registered public accounting firm during the next 12 months. Any such pre-approval details the particular service or type of services to be provided and is also generally subject to a maximum dollar amount.

During our 2024 and 2023 fiscal years, no services were provided to us by Ernst & Young other than in accordance with the pre-approval policies and procedures described above.

133

PART IV

Item 15. Exhibits, Consolidated Financial Statement Schedules.

(a) The following documents are filed as part of this Annual Report on Form 10-K:

(1) Consolidated Financial Statements:

Page