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 late 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, focuses on the CARTA approach. CARTA refers to Chimeric Antigen Receptor T cells for Autoimmunity and is designed to potentially reset the immune system. Based on clinical data reported to date, 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, or 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, weight-based infusion of T cells that are 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 transitional, naïve B cells. This approach has demonstrated the potential to reset the immune system and result in meaningful clinical responses without chronic therapy requirements in patients. The efficacy and safety of rese-cel was recently reviewed along with all other commercial and academic constructs in development in a February 2026 Nature Biotechnology publication.

In December 2025, we initiated a registrational trial with rese-cel for patients with dermatomyositis or anti-synthetase syndrome. In addition, we have ongoing Phase 1/2 trials evaluating rese-cel with a standard preconditioning regimen, fludarabine and cyclophosphamide, in systemic lupus erythematosus, or SLE, in patients with active lupus nephritis, or LN, or active SLE without renal involvement, systemic sclerosis, or SSc, and generalized myasthenia gravis, or gMG. In addition to our core development program across multiple indications using standard preconditioning regimens and standard manufacturing processes with partnered Contract and Development Manufacturing Organizations, or CDMOs, based on early data from a phase 1/2 trial evaluating rese-cel without preconditioning in pemphigus vulgaris patients, we are evaluating rese-cel without preconditioning in non-renal SLE and LN patients.

In addition, in January 2026 we announced INDa clearance for rese-cel to be manufactured using an automated manufacturing platform – the Cell ShuttleTM from Cellares - offering the potential for scalability to produce rese-cel

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for thousands of patients per year with minimal capital investment by the Company. The first clinical experience from these patients is expected to be presented in the first half of 2026.

Durability data from the no-preconditioning SLE, LN and PV patients as well as the patients treated with rese-cel manufactured by the Cellares Cell ShuttleTM is expected to be presented in the second half of 2026.

RESET-Myositis®

The three adult myositis subtypes, dermatomyositis, or DM, anti-synthetase syndrome, or ASyS, and immune-mediated necrotizing myopathy, or IMNM, being evaluated in the RESET-Myositis® Phase 1/2 clinical trial of rese-cel affect approximately 80,000 patients in the U.S. Myositis typically affects middle-aged individuals, particularly women, and disease is often refractory, despite existing therapies. In the United States, we believe approximately 20% to 25% of the prevalent population, or 16,000 to 20,000 people, would be potentially eligible patients for rese-cel.

The RESET-Myositis® Phase 1/2 clinical trial is designed to treat at least six patients with DM, or ASyS, at least six patients with IMNM, as well as at least six patients with juvenile idiopathic inflammatory myopathy, or JIIM, all in separate parallel cohorts, with a single weight-based dose of 1.0 x 106 cells/kg. We announced the FDA granted Fast Track Designation for rese-cel for the treatment of patients with dermatomyositis and Orphan Drug Designation for rese-cel for the treatment of myositis in January and February 2024, respectively. In March 2024, we announced the FDA granted Rare Pediatric Disease designation for rese-cel for juvenile dermatomyositis. In May 2025, we announced the FDA granted Regenerative Medicine Advanced Therapy, or RMAT, designation to rese-cel for the treatment of myositis.

Based on clinical data presented in October 2025 at the American College of Rheumatology, or the ACR, Convergence 2025, we have initiated a DM/ASyS registrational cohort within the RESET-Myositis® trial. There are approximately 60,000 patients with DM in the U.S. who have IVIg as their only FDA-approved treatment option and approximately 15,000 patients with ASyS in the U.S. who have no FDA-approved treatment options. Our registrational trial design includes a 16-week primary endpoint of moderate or major TIS response while off immunomodulators and on no or low-dose steroids. Based on the safety data from the phase 1/2 cohort, the protocol permits outpatient administration. In addition, we are planning for a pediatric submission in juvenile idiopathic inflammatory myopathy, or JIIM, based on data available at the time of adult submission from the ongoing Ph 1/2 cohort to support a pediatric label claim.

The planned size of 17 patients for the registrational cohort is based on the assumed treatment effect of rese-cel in DM/ASyS patients and an estimated background rate. The estimated background rate will be determined from a retrospective analysis of an external myositis patient registry and will include patients with similar inclusion criteria as those in the registrational DM/ASyS cohort. Based on comprehensive literature review to estimate the background rate, we estimate the likelihood of an active, refractory myositis patient achieving moderate or major TIS response within 16 weeks and concurrently discontinuing all immunomodulators to be less than 10%. Changes in the assumed background rate would result in a change in the number of rese-cel treated patients who would need to achieve the primary endpoint in the 17-patient registrational cohort.

The registrational cohorts will evaluate the same single, weight-based infusion of rese-cel at 1 x 106 cells/kg as used in the Phase 1/2 myositis cohorts with similar enrollment criteria. As presented at ACR Convergence 2025, all myositis patients in the Phase 1/2 DM/ASyS cohort with sufficient follow-up who met key registrational inclusion criteria exceeded the registrational primary endpoint, demonstrating major TIS responses with no immunomodulators. Based on discussions with the FDA, we plan to use pooled rese-cel safety data from across the entire RESETTM clinical trial program to supplement myositis specific safety data for the Biologics License Application, or BLA, submission in myositis, and the required safety database is expected to be approximately 100 autoimmune disease patients treated with the same single weight-based dose. We initiated enrollment in the registrational DM/ASyS cohort in December 2025 and anticipate BLA submission in 2027.

RESET-SLETM

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., with LN as the most common end-organ manifestation, affecting approximately 30-40% of SLE patients.

The RESET-SLETM Phase 1/2 clinical trial 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

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106 cells/kg. In May 2023, we announced the FDA granted Fast Track Designation for rese-cel in patients with SLE and LN. In November 2025, we announced the FDA granted RMAT designation to rese-cel for treatment of SLE and LN. In January 2026, Cabaletta announced registrational cohort designs in RESET-SLETM to evaluate the current rese-cel weight-based dose of 1 million cells/kg in a single infusion with preconditioning, including two independent, single-arm cohorts, one consisting of patients with non-renal SLE and one consisting of patients with LN each evaluating approximately 25 patients with unique endpoints in each cohort. Complete Phase 1/2 data from both cohorts is anticipated in the first half of 2026. Cabaletta will provide an update on next steps for these cohorts in 2026, subject to dose-ranging data evaluating rese-cel without preconditioning in lupus patients.

RESET-SScTM

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., 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, each in separate parallel cohorts, with a single weight-based dose of 1.0 x 106 cells/kg. 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 SSc in January and March 2024, respectively. In January 2026, Cabaletta announced the FDA granted RMAT designation to rese-cel for treatment of SSc. Complete Phase 1/2 data from both cohorts is anticipated in the first half of 2026, and we anticipate announcing the registrational cohort design for SSc in the first half of 2026.

RESET-MGTM

MG is a rare autoimmune disease characterized by autoantibodies that interfere with signaling at the neuromuscular junction, 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 100,000 patients in the U.S. 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.

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, with a single weight-based dose of 1.0 x 106 cells/kg.

In October 2025, we announced that rese-cel was generally well tolerated across two AChR-positive and two AChR-negative patients (both seronegative; no anti-MuSK or anti-LRP4 antibodies). No CRS (cytokine release syndrome) occurred in three of four patients, and grade 2 CRS occurred in AChR-pos-2 that resolved with no sequelae. As of the September 11, 2025 data cut-off, two evaluable patients (AChR-neg-1 and AChR-neg-2) remained off immunomodulatory medication and achieved significant improvements in MG-ADL (with AChR-neg-1 achieving Minimal Symptom Expression). AChR-pos-1 is not evaluable due to use of a prohibited cytotoxic medication that may have inhibited CAR T activity and AChR-pos-2 has insufficient follow-up.

Both cohorts have been fully enrolled. Complete Phase 1/2 data from both cohorts is anticipated in the first half of 2026, and we anticipate announcing the registrational cohort design for studies in MG in mid-2026.

RESET-PV®

Pemphigus vulgaris, or PV, is an autoimmune disease that occurs when the immune system produces antibodies that attack a protein called desmoglein, or DSG. DSG normally enables skin cells and the cells lining the inside of your mouth, nose, throat, eyelids, etc. to bind tightly together. Disruption by the antibodies directed to DSG causes the painful blisters and erosions characteristic of PV. Approximately 15,000 patients in the U.S. are affected by PV.

The ongoing RESET-PV® trial is designed to evaluate rese-cel as a monotherapy without preconditioning in patients with mucosal pemphigus vulgaris, or mPV, and mucocutaneous pemphigus vulgaris, or mcPV.

In October 2025, we announced that rese-cel exhibited similar CAR T cell expansion and contraction kinetics relative to translational data reported from other RESETTM trials with preconditioning. All three patients experienced substantial depletion of B cells within the first month post-infusion, with patients 2 and 3 achieving complete

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peripheral B cell depletion. In these two patients, rapid reduction in autoantibodies to desmoglein was observed and the increase in peak B cell activating factor, or BAFF, was at the low end of the range of patients dosed with rese-cel plus preconditioning from pre-infusion through the latest follow-up, suggestive of potential deep B cell depletion in the tissue. Additional follow up will be required to determine if the initial clinical effects are durable and to determine if the findings can be replicated in other autoimmune diseases. Rese-cel was generally well tolerated with no immune effector cell-associated neurotoxicity syndrome, or ICANS, reported as of the data cutoff. After infusion, patient 1 experienced transient fever (grade 1 cytokine release syndrome). Patient 2 required a course of steroids for a disease flare in the first two weeks following infusion after discontinuing immunomodulators.

PDAI activity scores have formed the basis for recent regulatory approvals in PV, and total PDAI scores in these patients were also reported to be consistent with the PDAI activity scores in the late breaking clinical trial session. PDAI improvements were most significant in the two patients who seemed to experience complete peripheral B cell depletion.

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 follow-on offerings of shares of our common stock and pre-funded warrants. As of December 31, 2025, we had $133.6 million in cash, cash equivalents and investments.

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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:

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

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

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costs related to sponsored research service agreements;

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

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licensing fees for intellectual property and know-how;

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

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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.

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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:

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

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

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

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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;

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receipt of regulatory approvals from applicable regulatory authorities;

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

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

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

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

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effectively competing with other therapies and treatment options;

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a continued acceptable safety and efficacy profile following approval;

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

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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 the Securities and Exchange Commission, or the SEC, requirements, insurance and investor relations costs.

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Other Income

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

Interest Expense

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

Other Income, net

Other income, net primarily consists of foreign currency gains and losses and proceeds received from the sale of our Pennsylvania research and development tax credits.

Results of Operations for the years ended December 31, 2025 and 2024

The following sets forth our results of operations:

Year Ended December 31,

(in thousands)

Statements of Operations Data:

Operating expenses:

Other income (expense):

Research and Development

Research and development expenses were $142.7 million for the year ended December 31, 2025 as compared to $97.2 million for the year ended December 31, 2024. The table below summarizes our research and development expenses:

Year Ended December 31,

(in thousands)

License of intellectual property — 1,523 (1,523 )

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

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$22.7 million increase in manufacturing costs primarily due to expanded cell processing capabilities, increase in patient enrollment and related activities, including those for commercial readiness;

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$17.3 million increase in clinical trial costs primarily due to higher enrollment and clinical trial sites across multiple clinical studies for rese-cel;

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$7.7 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 $1.3 million in stock-based compensation expense; partially offset by a

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$1.5 million decrease in license of intellectual property costs due 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; and

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$1.1 million decrease in development services due to lower spend on laboratory consumables and external research activities.

General and Administrative Expenses

General and administrative expenses were $29.5 million for the year ended December 31, 2025 as compared to $27.9 million for the year ended December 31, 2024. The increase of $1.6 million in our general and administrative expenses year over year includes:

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$1.6 million increase in personnel costs, primarily driven by higher personnel-related expenses, including a $0.2 million increase in stock-based compensation expense.

Interest Income

Interest income decreased by $4.0 million for the year ended December 31, 2025 as compared to the year ended December 31, 2024, primarily due to lower cash, cash equivalents and investment balances earning interest during 2025 as prior financing proceeds were utilized to fund operating activities, as well as reductions in interest rates on government securities.

Interest Expense

Interest expense increased $1.3 million for the year ended December 31, 2025 as compared to the year ended December 31, 2024, primarily as a result of finance lease arrangements from embedded leases within our manufacturing agreements with Minaris and Lonza.

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 and through December 31, 2025, 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 $384.0 million. As of December 31, 2025, we had $133.6 million in cash and cash equivalents which should enable us to fund our operations and capital expenditures into the fourth quarter 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, 2025, we had an accumulated deficit of $517.0 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

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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 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 31, 2025, we converted the Form S-3ASR to a Form S-3 (File No. 333-278126) by post-effective amendments. This Form S-3 was declared effective on March 31, 2025. We had a Sales Agreement with TD Securities (USA) LLC, as successor to Cowen and Company, LLC, or TD Cowen, to provide for the offering, issuance and sale of up to an aggregate amount of $200.0 million of common stock from time to time in “at-the-market” offerings, or the 2024 ATM Program, pursuant to its S-3, and subject to the limitations thereof. On June 11, 2025, the 2024 ATM Program with TD Cowen was terminated. Prior to termination, we sold an aggregate of 2,609,865 shares pursuant to the 2024 ATM Program for total net proceeds of $7.7 million, consisting of $5.1 million in 2024 and $2.6 million in 2025.

On August 7, 2025, we filed a Registration Statement (File No. 333-289339) with the SEC, which was declared effective on August 15, 2025, or the 2025 Shelf Registration Statement, 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 with TD Cowen to provide for the offering, issuance and sale of up to an aggregate amount of $150.0 million of our common stock from time to time in “at-the-market” offerings, or the 2025 ATM Program, under the 2025 Shelf Registration Statement and subject to the limitations thereof, or the 2025 Sales Agreement. During the year ended December 31, 2025, we sold 4,160,176 shares pursuant to the 2025 ATM Program for net proceeds of $10.2 million. Subsequent to December 31, 2025, we sold 8,055,260 shares of common stock pursuant to the 2025 ATM Program for net proceeds of $22.6 million.

June 2025 Financing

In June 2025, we issued (i) 39,200,000 shares of our common stock and accompanying warrants to purchase an aggregate of 39,200,000 shares of common stock (or pre-funded warrants in lieu thereof) and (ii) in lieu of common stock, to certain investors, pre-funded warrants to purchase an aggregate of up to 10,800,000 shares of our common stock and accompanying warrants to purchase an aggregate of 10,800,000 shares of common stock (or pre-funded warrants in lieu thereof), at an exercise price of $0.00001 per pre-funded warrant. The combined offering price of each share of common stock and accompanying common stock warrant was $2.00. The combined offering price of each pre-funded warrant and accompanying common stock warrant was $1.99999. The pre-funded warrants were

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exercisable immediately. The common stock and pre-funded warrants were sold in combination with an accompanying common stock warrant to purchase one share of common stock (or a pre-funded warrant in lieu thereof) for each share of common stock or pre-funded warrant sold. Each common stock warrant has an exercise price per share of $2.50. The common stock warrants are immediately exercisable from the date of issuance and will expire on September 12, 2026, fifteen months from the date of issuance. Aggregate net proceeds were $93.6 million after deducting underwriting discounts and commissions and offering expenses. As of December 31, 2025, 4,800,000 pre-funded warrants had been exercised and 6,000,000 remain outstanding. As of December 31, 2025, no common stock warrants had been exercised and 53,090,190 remain outstanding. Subsequent to December 31, 2025, 2,775,100 common stock warrants were exercised for proceeds of $6.9 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:

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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;

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

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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;

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

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

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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;

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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;

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the expenses needed to attract and retain skilled personnel;

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the costs associated with being a public company; and

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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 19 (20 )

Net decrease in cash and cash equivalents $ (80,980 ) $ (29,276 )

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Operating Activities

During the year ended December 31, 2025, cash used in operating activities of $131.1 million was attributable to our net loss of $167.9 million, partially offset by non-cash charges of $37.2 million for stock-based compensation charges, amortization of finance lease, non-cash operating lease expense, depreciation, accretion of operating lease liabilities and foreign currency exchange rates and a net change of $0.4 million in our net operating assets and liabilities.

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.

Investing Activities

During the year ended December 31, 2025, cash used in investing activities of $50.2 million was attributable to $99.0 million of purchases of investments and $1.2 million of purchases of property and equipment partially offset by $50.0 million from the maturity of short-term investments.

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.

Financing Activities

During the year ended December 31, 2025, cash provided by financing activities of $100.3 million was attributable to $93.6 million in sales of common stock, warrants and pre-funded warrants to purchase common stock, net of issuance costs paid, $12.7 million in sales of common stock under our 2024 ATM Program and 2025 ATM Program, net of sales agent commission and fees and $0.3 million from the purchases of shares under our 2019 Employee Stock Purchase Plan, or 2019 ESPP, offset by $6.3 million in principal payments on finance leases.

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 under our 2024 ATM Program, net of issuance costs paid, $1.7 million from the exercise of employee stock and purchases of shares under our 2019 ESPP, offset by $0.9 million in principal payments on finance leases.

Contractual Obligations and Commitments

We lease our headquarters office space and laboratory 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 for our laboratory space was amended in September 2024 through August 2026 and further extended in October 2025 through November 2026. We also have embedded manufacturing leases with Minaris and Lonza, our cell processing manufacturing partners. Minaris' lease term is through August 2026 and Lonza's is for an initial 12 months with the ability to extend the manufacturing period on a rolling basis. Total undiscounted aggregate future finance and operating lease obligations under all of our leases as of December 31, 2025 are $28.8 million. See Note 9 of the consolidated financial statements for additional detail on our leases.

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

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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, we and Oxford entered into a third amendment to the LSA to update the patent schedule. In June 2024, we and Oxford entered into a fourth amendment to the LSA eliminating royalties on net sales of products that incorporate the Oxford technology if Oxford manufactures the vector. Starting in December 2024, we and Oxford entered into work orders for certain process characterization and process performance qualification activities as part of commercial readiness activities. We can terminate the LSA or any work order under the LSA at will upon advance written notice and subject to certain 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.

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•

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, 2025, we are unable to estimate the timing or likelihood of achieving the milestones or making future product sales.

o

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.

•

Minaris Manufacturing agreement. In January 2021, we entered into the Development and Manufacturing Services Agreement, or the Minaris Agreement, to serve as an additional cell processing manufacturing partner for the MusCAARTesTMtrial. In August 2023, we entered into new work orders under the Minaris Agreement for Minaris 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, Minaris 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 Minaris 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. In February 2026, we notified Minaris that we intend to permit the term to expire in August 2026.

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•

Lonza Manufacturing agreement. 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. The Lonza Agreement has a term of five years and can be extended for an additional three year term upon notice to Lonza at least 18 months prior to the expiration of the Lonza Agreement. We can terminate the Lonza Agreement at will upon nine months advance written notice to Lonza subject to the terms of the Lonza Agreement. Lonza can terminate the Lonza Agreement at will upon 24 months advance written notice to us subject to the terms of the Lonza Agreement. Under the initial work order, Lonza will perform cell therapy manufacturing activities for our CAR-T cell therapy product, rese-cel, for an initial term of 12 months with the ability to extend the manufacturing period on a rolling basis subject to the terms of the Lonza Agreement.

•

Cellares Agreement. In January 2026, we entered into a Development and Clinical Manufacturing Services Agreement, or the Cellares Agreement, with Cellares to serve as one of our manufacturing partners for the clinical development of rese-cel in multiple indications, including potential late-stage clinical trials and preparations for commercial readiness. The Cellares Agreement has a term of five years. We can terminate the Cellares Agreement at will by providing a certain advance written notice to Cellares subject to the terms of the Cellares Agreement. Cellares can terminate the Cellares Agreement at will by providing a certain advance written notice to us subject to the terms of the Cellares Agreement. Under the initial work order, Cellares will perform clinical cell therapy manufacturing activities for our CAR-T cell therapy product, rese-cel.

•

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.

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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.

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.

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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 and investments of $133.6 million as of December 31, 2025. We generally hold our cash in interest-bearing money market treasury fund accounts and our investments are available-for-sale debt securities, which are invested in U.S. treasury securities. 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.

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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, 2025, 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, 2025.

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, 2025. 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, 2025, our internal control over financial reporting was effective.

Attestation Report of the Registered Public Accounting Firm

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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.

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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, 2025 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, 2025, 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.

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

Not applicable.

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PART III

Item 10. Directors, Executive Officers and Corporate Governance.

Except as set forth below, the information required by this item is incorporated by reference from our definitive Proxy Statement to be filed with the SEC in connection with our 2026 Annual Meeting of Stockholders within 120 days after the end of the fiscal year ended December 31, 2025.

We have adopted a Code of Business Conduct and Ethics that applies to all of our directors, officers and employees, including our principal executive officer and principal financial officer. The Code of Business Conduct and Ethics is posted on our website at http://investors.cabalettabio.com/corporate-governance/governance-highlights.

We intend to satisfy the disclosure requirement under Item 5.05 of Form 8-K regarding an amendment to, or waiver from, a provision of this Code of Business Conduct and Ethics by posting such information on our website, at the address and location specified above and, to the extent required by the listing standards of The Nasdaq Global Select Market, by filing a Current Report on Form 8-K with the SEC, disclosing such information.

Item 11. Executive Compensation.

The information required by this Item 11 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2026 Annual Meeting of Stockholders within 120 days after the end of the fiscal year ended December 31, 2025 and is incorporated herein by reference.

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

The information required by this Item 12 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2026 Annual Meeting of Stockholders within 120 days after the end of the fiscal year ended December 31, 2025 and is incorporated herein by reference.

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

The information required by this Item 13 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2026 Annual Meeting of Stockholders within 120 days after the end of the fiscal year ended December 31, 2025 and is incorporated herein by reference.

Item 14. Principal Accounting Fees and Services.

The information required by this Item 14 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2026 Annual Meeting of Stockholders within 120 days after the end of the fiscal year ended December 31, 2025 and is incorporated herein by reference.

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

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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

Report of Independent Registered Public Accounting Firm F-2

Consolidated Balance Sheets as of December 31, 2025 and 2024 F-5

Notes to Consolidated Financial Statements F-9

(2) Consolidated Financial Statement Schedules:

All consolidated financial statement schedules have been omitted because they are not applicable, not required or the information required is shown in the consolidated financial statements or the notes thereto.

(3) Exhibits. The exhibits required by Item 601 of Regulation S-K and Item 15(b) of this Annual Report on Form 10-K are listed in the Exhibit Index immediately preceding the signature page of this Annual Report on Form 10-K. The exhibits listed in the Exhibit Index are incorporated by reference herein.

Item 16. Form 10-K Summary

None.

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INDEX TO FINANCIAL STATEMENTS

Page

Report of Independent Registered Public Accounting Firm F-2

Consolidated Balance Sheets as of December 31, 2025 and 2024 F-5

Notes to Consolidated Financial Statements F-9

F-1

Report of Independent Registered Public Accounting Firm

To the Stockholders and the Board of Directors of Cabaletta Bio, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Cabaletta Bio, Inc. (the Company) as of December 31, 2025 and 2024, the related consolidated statements of operations and comprehensive loss, stockholders’ equity and cash flows for each of the two years in the period ended December 31, 2025, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2025, in conformity with U.S. generally accepted accounting principles.

The Company's Ability to Continue as a Going Concern

The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern. As discussed in Note 1 to the consolidated financial statements, the Company has suffered recurring losses from operations and has stated that substantial doubt exists about the Company’s ability to continue as a going concern. Management's evaluation of the events and conditions and management’s plans regarding these matters are also described in Note 1. The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

F-2

Critical Audit Matters

The critical audit matters communicated below are matters arising from the current period audit of the financial statements that were communicated or required to be communicated to the audit committee and that: (1) relate to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matters below, providing separate opinions on the critical audit matters or on the accounts or disclosures to which they relate.

Accounting for Accrued Clinical Trial Expenses

Accounting for Common Stock Warrants

F-3

/s/ Ernst & Young LLP

We have served as the Company’s auditor since 2018.

Philadelphia, Pennsylvania

March 23, 2026

F-4

CABALETTA BIO, INC.

Consolidated Balance Sheets

(in thousands, except share and per share amounts)

Year Ended December 31,

Assets

Current assets:

Short-term investments 50,617 —

Prepaid expenses and other current assets 5,272 2,713

Finance lease right-of-use assets 15,700 7,020

Operating lease right-of-use assets 3,431 6,315

Liabilities and stockholders’ equity

Current liabilities:

Accrued and other current liabilities 19,298 12,188

Finance lease liabilities, current portion 20,758 5,989

Operating lease liabilities, current portion 3,461 3,986

Finance lease liabilities, net of current portion 2,879 3,241

Operating lease liabilities, net of current portion — 2,384

Commitments and contingencies (see Notes 6 and 7)

Stockholders’ equity:

Accumulated other comprehensive income 25 —

Total liabilities and stockholders’ equity $ 165,083 $ 185,046

The accompanying notes are an integral part of these consolidated financial statements.

F-5

CABALETTA BIO, INC.

Consolidated Statements of Operations and Comprehensive Loss

(in thousands, except share and per share amounts)

Year Ended December 31,

Operating expenses:

Other income (expense):

Other income, net 358 —

Other comprehensive income:

The accompanying notes are an integral part of these consolidated financial statements.

F-6

CABALETTA BIO, INC.

Consolidated Statements of Stockholders’ Equity

(in thousands, except share amounts)

Common Stock

Issuance of common stock under employee stock purchase plan 58,056 — 269 — — 269

Net unrealized losses on available-for-sale securities — — — (39 ) — (39 )

Net unrealized gains on available-for-sale securities — — — 25 — 25

The accompanying notes are an integral part of these consolidated financial statements.

F-7

CABALETTA BIO, INC.

Consolidated Statements of Cash Flows

(in thousands)

Year Ended December 31,

Cash flows from operating activities:

Adjustments to reconcile net loss to net cash used in operating activities:

Non-cash operating lease expense 3,671 2,838

Accretion of operating lease liabilities 532 405

Amortization of discount on investments (1,555 ) (1,528 )

Loss on foreign currency exchange rates 225 38

Changes in operating assets and liabilities:

Prepaid expenses and other current assets (2,559 ) 528

Accrued and other current liabilities 7,432 3,947

Accrued interest payable under finance lease 291 —

Net cash used in operating activities (131,080 ) (88,222 )

Cash flows from investing activities:

Purchases of property and equipment (1,229 ) (2,211 )

Purchases of investments (99,037 ) —

Proceeds from maturities of investments 50,000 49,500

Net cash (used in) provided by investing activities (50,266 ) 47,289

Cash flows from financing activities:

Principal payments on finance leases (6,261 ) (897 )

Net cash provided by financing activities 100,347 11,677

Effect of exchange rate changes on cash and cash equivalents 19 (20 )

Net decrease in cash and cash equivalents (80,980 ) (29,276 )

Cash and cash equivalents—beginning of period 163,962 193,238

Cash and cash equivalents—end of period $ 82,982 $ 163,962

Supplemental disclosures

Cash paid for interest $ 1,713 $ 748

The accompanying notes are an integral part of these consolidated financial statements.

F-8

CABALETTA BIO, INC.

Notes to the Consolidated Financial Statements

(in thousands, except share and per share amounts)

1. Basis of Presentation

Cabaletta Bio, Inc. (the Company or Cabaletta) was incorporated in April 2017 in the State of Delaware as Tycho Therapeutics, Inc. and, in August 2018, changed its name to Cabaletta Bio, Inc. The consolidated financial statements include the accounts of Cabaletta and its wholly owned subsidiaries: Cabaletta Bio GmbH and Cabaletta Bio (Germany) GmbH.

The Company is headquartered in Philadelphia, Pennsylvania. Cabaletta is a clinical-stage biotechnology company focused on the discovery and development of engineered T cell therapies for autoimmune diseases. Principal operations commenced in April 2018.

Risks and Uncertainties

The Company does not expect to generate revenue from sales of engineered T cell therapies for autoimmune diseases or any other revenue unless and until the Company completes preclinical and clinical development and obtains regulatory approval for one or more product candidates. If the Company seeks to obtain regulatory approval for any of its product candidates, the Company expects to incur significant commercialization expenses.

The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing. As a result, the Company is unable to predict the timing or amount of increased expenses or when or if the Company will be able to achieve or maintain profitability. Further, the Company is dependent on third parties for certain research and development activities, including manufacturing services (Note 6 and Note 7). Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization. Even if the Company is able to generate revenues from the sale of its product candidates, if approved, it may not become profitable. If the Company fails to become profitable or is unable to sustain profitability on a continuing basis, then it may be unable to continue its operations at planned levels and be forced to reduce its operations.

Liquidity and Going Concern

In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern, ("ASC 205-40") the Company evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern. The Company has sustained annual operating losses since inception and expects to continue to generate operating losses for the foreseeable future. As of December 31, 2025, the Company has incurred an accumulated deficit of $516,957 and has cash, cash equivalents and investments of $133,599. The Company’s ultimate success depends on the outcome of its research and development activities. Management expects to incur additional losses in the future as it continues its research and development and will need to raise additional capital to fully implement its business plan and to fund its operations. The Company intends to raise such additional capital through a combination of equity offerings, debt financings, government funding arrangements, strategic alliances or other sources. However, if such financing is not available at adequate levels and on a timely basis, or such agreements are not available on favorable terms, or at all, as and when needed, the Company will need to reevaluate its operating plan and may be required to delay or discontinue the development of one or more of its product candidates or operational initiatives. Based on the Company’s current operating plan, there is substantial doubt about the Company’s ability to continue as a going concern for at least twelve months from the issuance date of this Annual Report on Form 10-K, and the Company will need to obtain additional funding. The Company's cash forecast contains estimates and assumptions based on success of ongoing clinical trials, and management cannot predict the amount or timing of all expenditures with certainty. Accordingly, the Company has concluded that substantial doubt exists about the Company’s ability to continue as a going concern. The accompanying financial statements have been

F-9

prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business.

2. Summary of Significant Accounting Policies

Principles of Consolidation

The accompanying consolidated financial statements have been prepared in conformity with generally accepted accounting principles in the United States (GAAP) and under the rules and regulations of the U.S. Securities and Exchange Commission (SEC). All intercompany balances and transactions have been eliminated in consolidation.

Use of Estimates

The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions made in the accompanying consolidated financial statements include but are not limited to advance payments and accruals related to the Company’s research and development expenses. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could differ from those estimates.

Off-Balance Sheet Risk and Concentrations of Credit Risk

Financial instruments, which potentially subject the Company to significant concentrations of credit risk, consist of cash and cash equivalents, which are invested in U.S. treasury-based money market funds, and available-for-sale debt securities, which are invested in U.S. treasury securities. A portion of the Company’s cash is maintained at federally insured financial institutions, and account balances may at times exceed federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk. The Company has no off‐balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements.

The Company considers all highly liquid investments purchased with original maturities of three months or less from the purchase date to be cash equivalents. Cash equivalents consist primarily of amounts invested in money market accounts and U.S. treasury securities.

Investments

Investments are available-for-sale and carried at estimated fair value. The Company’s valuations of available-for-sale debt securities are generally derived from independent pricing services based upon quoted prices in active markets for similar securities, with prices adjusted for yield and number of days to maturity, or based on industry models using data inputs, such as interest rates and prices that can be directly observed or corroborated in active markets. Management determines the appropriate classification of its investments in debt securities at the time of purchase and at the end of each reporting period. Investments with original maturities beyond three months at the date of purchase and which mature at, or less than, twelve months from the balance sheet date are classified as current.

Unrealized gains and losses are excluded from earnings and are reported as a component of comprehensive income. The Company periodically evaluates whether declines in fair values of its available-for-sale securities below their book value are other-than-temporary. This evaluation consists of several qualitative and quantitative factors including the severity and duration of the unrealized loss as well as the Company’s ability and intent to hold the available-for-sale security until a forecasted recovery occurs. Additionally, the Company assesses whether it has plans to sell the security or if more likely than not it will be required to sell any available-for-sale securities before recovery of its amortized cost basis. Realized gains and losses and declines in fair value judged to be other-than-temporary, if any, on available-for-sale securities are included in interest and other income, net. The cost of investments sold is based on the specific-identification method. Interest income on investments as well as amortization of discount or premium is included in interest income.

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Property, Plant and Equipment

Property, plant and equipment are recorded at cost less accumulated depreciation. Cost includes the acquisition costs and all costs necessary to bring the asset to the location and working condition necessary for its intended use. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the accompanying statements of operations. Expenditures for normal, recurring or periodic repairs and maintenance related to property and equipment are charged to expense as incurred. The cost for planned major maintenance activities, including the related acquisition or construction of assets, is capitalized if it will result in future economic benefits.

Estimated useful lives for property and equipment are as follows:

Property and equipment Estimated useful life

Laboratory equipment Three years

Furniture and fixtures Three years

Computer equipment Three years

Leasehold improvements Lesser of estimated useful life or remaining lease term

Fair Value Measurement

Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows:

Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2—Inputs (other than quoted prices included in Level 1) that are either directly or indirectly observable for the asset or liability. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active.

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Leases

The Company has leases related to its facilities used for offices and laboratory space, which are classified as operating leases as well as leases related to its manufacturing arrangements, which are classified as finance leases.

At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease and its classification based on the unique facts and circumstances present in the arrangement. Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and current and non-current lease liabilities, as applicable.

Lease liabilities and their corresponding right-of-use assets are initially recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the right-of-use asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate to discount lease payments. Subsequent to the initial measurement, the Company will continue to account for:

•

the lease liability at the net present value using the incremental borrowing rate that was in effect as of the lease commencement, lease modification, or transition date, and;

•

the finance lease and operating lease expense on a straight line basis.

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Leases with terms of 12 months or less are considered short-term leases and right-of-use assets and lease obligations are not recognized. Payments associated with short-term leases are expensed on a straight-line basis over the lease term.

In accordance with ASC 842, components of a lease should be split into three categories: lease components, non-lease components and non-components. The fixed and in-substance fixed contract consideration (including any consideration related to non-components) must be allocated based on the respective relative fair values to the lease components and non-lease components. Entities may elect not to separate lease and non-lease components. Rather, entities would account for each lease component and related non-lease component together as a single lease component. The Company has elected to aggregate all lease and non-lease components for each class of underlying assets into a single lease component for real-estate leases and embedded manufacturing arrangements.

ASC 842 allows for the use of judgment in determining whether the assumed lease term is for a major part of the remaining economic life of the underlying asset and whether the present value of lease payments represents substantially all of the fair value of the underlying asset. The Company applies the guidance in ASC 842-10-55-2 to assist in determining lease classification across its leases.

Research and Development Expenses

Research and development costs include costs incurred for internal and external research and development activities and are expensed as incurred in the accompanying statements of operations. Research and development costs consist of salaries and benefits, including associated stock-based compensation, and laboratory supplies and facility costs, as well as fees paid to entities that conduct certain research and development and clinical trial activities on the Company’s behalf.

The Company records accrued liabilities for estimated costs of research and development activities conducted by service providers, which include preclinical studies, contract manufacturing activities and clinical trial activities. The Company records the estimated costs of research and development activities based upon the estimated amount of services provided and in accordance with agreements established with service providers and includes these costs in accrued and other current liabilities in the accompanying balance sheets and within research and development expense in the accompanying 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. The Company makes significant judgments and estimates in determining the accrued liabilities and prepaid expenses in each reporting period. As actual costs become known, the Company adjusts its accrued liabilities and prepaid expenses. The Company has not experienced any material differences between accrued costs and actual costs incurred since its inception.

Stock-based Compensation

The Company measures its stock-based awards granted to employees and non-employees based on the estimated fair values of the awards on the respective grant dates. The Company uses the Black-Scholes option-pricing model (Black-Scholes) to estimate the fair value of its stock-based awards. The Company recognizes compensation expense for time-based awards on a straight-line basis over the requisite service period, which is generally the vesting period of the award. The Company accounts for forfeitures of stock option awards as they occur.

Income Taxes

The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to temporary differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax base, as well as for net operating loss carryforwards and research and development credits, and are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled.

Valuation allowances are established when necessary to reduce deferred tax assets where, based upon the available evidence, the Company concludes that it is more-likely-than-not that the deferred tax assets will not be realized. In evaluating its ability to recover deferred tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a

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jurisdiction-by-jurisdiction basis. Because of the uncertainty of the realization of deferred tax assets, the Company has recorded a full valuation allowance against its deferred tax assets.

Reserves are provided for tax benefits for which realization is uncertain. Such benefits are only recognized when the underlying tax position is considered more-likely-than-not to be sustained on examination by a taxing authority, assuming they possess full knowledge of the position and facts. Interest and penalties related to uncertain tax positions are recognized in the provision of income taxes; however, the Company currently has no interest or penalties related to uncertain income tax benefits.

Net Loss Per Share

The Company calculates basic and diluted net loss per share in conformity with the two-class method required for participating securities because the Company had both voting and non-voting common stock outstanding for a portion of 2024. The rights, including the liquidation and dividend rights, of the holders of the voting and non-voting common stock are identical, except with respect to voting. Each share of non-voting common stock may be converted at any time into one share of voting common stock at the option of its holder by providing written notice to the Company, subject to the limitations provided for in the amended and restated certificate of incorporation. As of December 31, 2024, no shares of non-voting common stock remain outstanding.

Basic net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted average number of shares of common stock, including any pre-funded warrants to purchase shares of common stock that may be outstanding. The undistributed loss for each year is allocated to common stockholders based on the contractual participation rights of the voting and non-voting common stock as if the losses for the year had been distributed. As the liquidation and dividend rights are identical, the undistributed losses are allocated on a proportionate basis. Diluted net loss per share attributable to common stockholders is computed under the if-converted method and assumes that all non-voting common stock has been converted to common stock. Since the Company was in a loss position for all periods presented, the effects of the other potentially dilutive securities are antidilutive.

Segments

Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the Chief Operating Decision Maker (CODM) in deciding how to allocate resources to an individual segment and in assessing performance. The Company’s CODM is its Chief Executive Officer (CEO). The Company has determined it operates in a single operating segment and has one reportable segment. Refer to Note 8 – Segment Reporting for further information related to our segment.

Deferred Offering Costs

The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated.

After consummation of the equity financing, these costs are recorded as a reduction to the carrying value of stockholders’ equity as a reduction of additional paid-in capital or equity generated as a result of such offering. Should an in-process equity financing be abandoned, the deferred offering costs will be expensed immediately as a charge to operating expenses in the statements of operations and comprehensive loss.

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Recently Adopted Accounting Pronouncements

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures. ASU 2023-09 enhances the transparency about income tax information through improvements to income tax disclosures primarily related to the rate reconciliation and income taxes paid information. The Company adopted this ASU for the annual period ended December 31, 2025 and the amendments have been applied retrospectively to all prior periods presented in the financial statements. Refer to Note 11 – Income Taxes for further information.

Recently Issued Accounting Pronouncements

In November 2024, the FASB issued ASU 2024-03, Income Statement (Subtopic 220-40): Reporting Comprehensive Income-Expense Disaggregation Disclosures. ASU 2024-03 requires enhanced disclosures about components of expense captions on the face of the income statement. This standard will be effective for fiscal years beginning after December 15, 2026. Early adoption is permitted. ASU 2024-03 applies on a prospective basis for periods beginning after the effective date. However, retrospective application to any or all prior periods presented is permitted. The Company is currently planning to adopt this guidance when effective and is assessing the impact of the adoption on the Company’s consolidated financial statements and accompanying footnotes.

There have been no other new accounting pronouncements or changes to accounting pronouncements that, if adopted, would have or may have a material impact on the Company’s consolidated statements or disclosures.

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3. Fair Value Measurements

As of December 31, 2025 and 2024, the Company’s financial instruments included cash and cash equivalents, available-for-sale debt securities, accounts payable and accrued expenses. The carrying amounts for cash and cash equivalents, accounts payable and accrued expenses reported in the Company’s consolidated financial statements for these instruments approximate their respective fair values because of the short-term nature of these instruments.

The following tables present information about the Company’s financial assets measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values:

Financial assets

Cash equivalents:

Short-term investments:

Financial assets

Cash equivalents:

Money market funds are measured at fair value on a recurring basis using quoted prices and are classified as Level 1 inputs. Investments are measured at fair value based on inputs other than quoted prices that are derived from observable market data and are classified as Level 2 inputs.

For debt securities classified as available-for-sale investments, the Company records unrealized gains or losses resulting from changes in fair value between measurement dates as a component of other comprehensive income. The Company did not hold any available-for-sale securities as of December 31, 2024.

Amortized Cost Gross Unrealized Gains Fair value

Financial assets

Included in cash and cash equivalents 82,982 — 82,982

U.S. Treasury securities - due in one year or less

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4. Property, Plant and Equipment

Property, plant and equipment consists of the following:

December 31,

Total property, plant and equipment 9,074 8,249

Less: accumulated depreciation (7,152 ) (5,506 )

Property, plant and equipment, net $ 1,922 $ 2,743

Depreciation expense was $1,646 and $1,711 for the years ended December 31, 2025 and 2024, respectively.

5. Accrued and Other Current Liabilities

Accrued and other current liabilities consist of the following:

December 31,

Clinical trial research and development services 5,335 1,236

Manufacturing and other research and development services 3,774 2,255

General and administrative services 393 342

6. Collaborations, Licensing Agreements and Other Agreements

Amended and Restated License Agreement with the Trustees of the University of Pennsylvania and Children’s Hospital of Philadelphia

In August 2018, the Company entered into a license agreement with the University of Pennsylvania (Penn), as amended and restated in July 2019 to include the Children’s Hospital of Philadelphia (CHOP) as a party, and as amended in May 2020 and October 2021 (the License Agreement) pursuant to which the Company obtained (a) a non-exclusive, non-sublicensable worldwide license to certain of Penn’s intellectual property to conduct research, product development, clinical trials, cell manufacturing and other activities, and (b) an exclusive, worldwide, royalty-bearing right and license, with a right to sublicense, on a target-by-target basis, under certain of Penn’s intellectual property to make, use, sell, offer for sale, import, and otherwise commercialize products for the treatment of autoimmune and alloimmune diseases. Unless earlier terminated, the License Agreement expires on the expiration or abandonment or other termination of the last valid claim in Penn’s intellectual property licensed by the Company. The Company may terminate the License Agreement at any time for convenience upon 60 days' written notice. In the event of an uncured, material breach, Penn may terminate the License Agreement upon 60 days' written notice. Under the terms of the License Agreement, the Company was obligated to pay $2,000 annually for three years beginning August 2018 for funding to the laboratories of each of Drs. Milone and Payne. This was satisfied through completed sponsored research agreements with a total cost of $12,560. During the term of the License Agreement until the first commercial sale of the first product, the Company is obligated to pay Penn a non-refundable, non-creditable annual license maintenance fee of $10. In May 2020, the Company paid Penn an additional, non-refundable, non-creditable license fee of $33 under the amended License Agreement.

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The Company is 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 the Company is able to successfully develop and launch multiple products under the License Agreement, total milestone payments could be approximately $21,000. 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 the Company or its sublicensees that contain or incorporate, or are covered by, the intellectual property licensed by the Company. To the extent the Company sublicenses its 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. There were no amounts due under the License Agreement as of December 31, 2025.

Master Translational Research Services Agreements

In October 2018 and February 2023, the Company entered into services agreements (the CAART and CARTA Services Agreements) with Penn for research, development and manufacturing services from various laboratories within Penn. The activities are detailed in separately executed Penn organization-specific addenda. In May 2020, the Company amended its Addendum with the Center for Advanced Retinal and Ocular Therapeutics (CAROT) to expand access to vector manufacturing.

Research and development expense recognized under executed addenda to the master translational research services agreements with Penn was $5,062 and $3,250 for the years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, the Company had no remaining commitments under the CARTA Services Agreement.

Exclusive License Agreement with IASO Biotherapeutics

On October 7, 2022, the Company entered into an Exclusive License Agreement (the IASO Agreement) with Nanjing IASO Biotherapeutics Co., Ltd. (IASO). Pursuant to the IASO Agreement, the Company received an exclusive, worldwide license under certain IASO intellectual property to use a novel clinical-stage anti-CD19 binder to develop, manufacture, commercialize and otherwise exploit T cell products directed to CD19 for the purpose of diagnosis, prevention or treatment of any autoimmune or alloimmune indications in humans. As partial consideration for the exclusive license, IASO received an upfront payment of $2,500. 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 $162,000, along with tiered mid-single digit royalties on future net sales for licensed products that may result from the IASO Agreement. Upon the U.S. Food and Drug Association’s clearance of the rese-cel Investigational New Drug application for the treatment of systemic lupus erythematosus in March 2023, a milestone payment of $1,000 was recognized in the accompanying statements of operations. A milestone payment of $1,500 was paid to IASO in the first quarter of 2024 after the first patient in a rese-cel trial was dosed.

IASO has the right of first negotiation if the Company desires to grant a third party an exclusive license to develop, manufacture, commercialize or otherwise exploit the licensed products in the Greater China region. Pursuant to the IASO Agreement, each of IASO and the Company have agreed, subject to certain exceptions, to refrain from engaging in certain competitive activities with respect to certain programs. The Company also may sublicense through multiple tiers the rights granted to it by IASO under the IASO Agreement at any time, however, it 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. Each of the Company and IASO may terminate the Agreement for a material, uncured breach or insolvency of the other party. The Company may also terminate the Agreement at will upon advance written notice and in the event IASO rejects the Agreement due to bankruptcy-related matters. IASO may also terminate the Agreement if the Company fails to achieve certain specified diligence milestones in a timely manner and/or if the Company commences any patent challenges with respect to the patents and patent applications relating to the licensed sequence, in each case upon advance written notice.

Licence and Supply Agreement with Oxford Biomedica

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In December 2021, the Company entered into a Licence and Supply agreement (LSA) with Oxford Biomedica (UK) Limited (Oxford), wherein the LSA grants the Company a non-exclusive license to Oxford’s LentiVector® platform for its application in the Company’s DSG3-CAART program and put in place a multi-year vector supply agreement. Oxford is eligible to receive regulatory and sales milestones in the low tens of millions and royalties in the low single digits on net sales of products that incorporate the Oxford technology. In May 2023, the Company amended the LSA with Oxford to expand the license to include the Company's rese-cel program for an upfront fee of $500. In August 2023, the Company and Oxford entered into a vector supply agreement for rese-cel, and a related second amendment to the LSA, with a total cost under the vector supply agreement of up to approximately $5,000, which has been fully expensed as of December 31, 2024. In February 2024, the Company and Oxford entered into a third amendment to the LSA to update the patent schedule. In June 2024, the Company and Oxford entered into a fourth amendment to the LSA eliminating royalties on net sales of products that incorporate the Oxford technology if Oxford manufactures the vector. Starting in December 2024, the Company and Oxford entered into work orders with a cost of approximately $23,000 for certain process characterization and process performance qualification activities as part of commercial readiness activities. As of December 31, 2025, the Company has recognized project to date expense of $8,673 related to these activities. The Company can terminate the LSA or any work order under the LSA at will upon advance written notice and subject to certain cancellation fees.

Option and License Agreement with Autolus

In January 2023, the Company entered into an Option and License Agreement (Autolus Agreement) with Autolus Holdings (UK) Limited (Autolus), wherein the Autolus Agreement granted the Company a non-exclusive license to access Autolus' RQR8 technology in its 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, the Company was required to pay Autolus an upfront license fee of $1,200 that was recognized as expense in the first quarter of 2023 in the accompanying statements of operations, of which $1,100 was paid in 2023 and $100 was paid in January 2024. Autolus is also eligible to receive regulatory milestones of up to $12,000 for each licensed target, sales milestones of up to a total of $15,000 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. The Company can terminate the Autolus Agreement at will upon advance written notice. Each of the Company and Autolus may terminate the Agreement for a material, uncured breach or insolvency of the other party.

7. Commitments and Contingencies

Manufacturing Agreements

In January 2021, the Company entered into a Development and Manufacturing Services Agreement (Minaris Agreement) with Minaris Advanced Therapies, LLC, or Minaris (f/k/a WuXi Advanced Therapies, Inc.) to serve as an additional cell processing manufacturing partner for the MuSK-CAART Phase 1 clinical trial, or MusCAARTesTM trial. The Minaris Agreement is scheduled to expire upon completion of Minaris' services related to MuSK-CAART and rese-cel. In August 2023, and as extended in August 2024, the Company entered into an agreement with Minaris to serve as one of the Company's 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, Minaris converted the Company’s non-dedicated suite to a dedicated suite for GMP manufacturing for the Company’s rese-cel and MuSK-CAART programs, or the Dedicated Suite, for an initial term of 18 months with two 18-month extensions at the Company’s sole option on six months' notice prior to the end of the term. In August 2024, the Company sent a notice to Minaris to extend the initial term of the Minaris Agreement by 18 months through August 2026. In addition, the Company agreed to certain monthly minimum runs. In August 2024, the 2023 work order related to GMP manufacturing was amended to reduce the minimum monthly runs through the end of 2024. In lieu of the original $1,500 termination fee under the terms of the Minaris Agreement, the Company would incur up to a $1,080 termination fee if it terminates both the rese-cel and MuSK-CAART work orders for any reason. The Company may terminate for convenience the Minaris Agreement or any work order with six months' prior written notice. However, the Company may not terminate the Dedicated Suite without terminating

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both the MuSK-CAART and rese-cel GMP run work orders. Minaris may terminate for convenience the Minaris Agreement or any work order on 18 months' prior written notice, but such notice may not be effective prior to February 2028. In February 2026, the Company notified Minaris that it intended to permit the term to expire in August 2026.

In December 2024, the Company entered into a Development and Manufacturing Services Agreement (the Lonza Agreement) with Lonza Houston Inc. (Lonza) to serve as one of the Company's manufacturing partners for the global clinical development of rese-cel in multiple indications, including potential late-stage clinical trials and preparations for commercial readiness. The Lonza Agreement has a term of five years and can be extended for an additional three year term upon notice to Lonza at least 18 months prior to the expiration of the Lonza Agreement. The Company can terminate the Lonza Agreement at will upon nine months advance written notice to Lonza subject to the terms of the Lonza Agreement. Lonza can terminate the Lonza Agreement at will upon 24 months advance written notice to Cabaletta subject to the terms of the Lonza Agreement. Under the initial work order, Lonza will perform cell therapy manufacturing activities for Cabaletta’s CAR-T cell therapy product, rese-cel, for an initial term of 12 months with the ability to extend the manufacturing period on a rolling basis subject to the terms of the Lonza Agreement.

Other Purchase Commitments

In the normal course of business, the Company enters into various purchase commitments with third-party contract manufacturers for the manufacture and processing of its 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.

Indemnification

The Company enters into certain types of contracts that contingently require the Company to indemnify various parties against claims from third parties. These contracts primarily relate to (i) the Company’s Amended and Restated Bylaws, as amended, (bylaws) under which the Company must indemnify directors and executive officers, and may indemnify other officers and employees, for liabilities arising out of their relationship, (ii) contracts under which the Company must indemnify directors and certain officers and consultants for liabilities arising out of their relationship, (iii) contracts under which the Company may be required to indemnify partners against certain claims, including claims from third parties asserting, among other things, infringement of their intellectual property rights, and (iv) procurement, consulting, or license agreements under which the Company may be required to indemnify vendors, consultants or licensors for certain claims, including claims that may be brought against them arising from the Company’s acts or omissions with respect to the supplied products, technology or services. From time to time, the Company may receive indemnification claims under these contracts in the normal course of business. In addition, under these contracts, the Company may have to modify the accused infringing intellectual property and/or refund amounts received.

In the event that one or more of these matters were to result in a claim against the Company, an adverse outcome, including a judgment or settlement, may have a material adverse effect on the Company’s future business, operating results or financial condition. It is not possible to determine the maximum potential amount under these contracts due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each particular agreement.

Litigation

From time to time, the Company may become involved in litigation or legal proceedings. While the outcome of any such proceedings cannot be predicted with certainty, as of December 31, 2025, the Company is not involved in any material litigation or legal proceedings that it would expect to have a material adverse impact on its financial position, results of operations, or cash flows.

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8. Segment Information

Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the CODM in deciding how to allocate resources to an individual segment and in assessing performance. The Company’s CODM is the CEO. The Company has determined it operates in a single operating segment and has one reportable segment. The segment consists of the development of clinical and preclinical product candidates for the discovery and development of innovative engineered T cell therapies and related administrative activities. The CODM assesses performance and allocates resources based on the Company’s consolidated statement of operations, which is reported on the income statement as consolidated net loss and considers forecast-to-actuals variances on a quarterly basis for expenses that are deemed significant. Further, the CODM reviews the segment’s assets based on the consolidated balance sheet to assess liquidity and funding capacity. The majority of the Company's assets are located in the United States.

The Company’s CODM views specific categories within expenses as significant given the direct correlation between cash burn and profitability as a pre-revenue company. Significant segment expenses, as provided to the CODM, are presented below. For additional information on the year over year change of segment expenses refer to Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

Year Ended December 31,

(in thousands)

Research and development expenses:

Manufacturing of preclinical and clinical supplies 38,240 15,523

License of intellectual property — 1,523

Other research and development costs (1) 2,569 2,215

Other income, net (358 ) —

(1) Other research and development costs includes costs associated with information technology, travel, medical and scientific symposiums and conferences.

9. Leases

The Company leases office and laboratory space and has two manufacturing agreements that have been determined to include embedded leases.

Operating lease commitments

The Company leases office and laboratory space which include rent escalations and are subject to additional variable charges, including common area maintenance, property taxes and property insurance. Given the variable nature of such costs, they are recognized as expense as incurred. Additionally, some of the Company’s leases are subject to certain fixed fees which the Company has determined to be non-lease components. The Company has elected the practical expedient to account for lease and non-lease components as a single-lease component and has included fixed payments related to non-lease components in calculating the operating lease liability. The lease term

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for our laboratory space was extended in October 2025 through November 2026 resulting in an increase of the right-of-use asset and lease liability of $787.

Finance lease commitments - Embedded leases

As described further in Note 7, in August 2023, the Company entered into new work orders under the Minaris Agreement for Minaris to serve as one of the Company’s cell processing manufacturing partners for the global clinical development of rese-cel. Minaris converted the Company’s non-dedicated suite to a Dedicated Suite for GMP manufacturing for the Company’s rese-cel and MuSK-CAART programs, for an initial term of 18 months. The terms of the August 2023 work orders included both fixed costs and contingent variable costs. The lease commenced October 1, 2023. In 2024, the Company remeasured the lease following the resolution of the contingency related to variable costs and an amendment to the 2023 work order, which extended the term of the agreement by an additional 18 months through August 2026. The Company may terminate the Dedicated Suite lease for convenience with six months’ prior written notice and up to a $1,080 termination fee if both the rese-cel and MuSK-CAART work orders are terminated. In February 2026, the Company notified Minaris that it intended to permit the term to expire in August 2026.

As described further in Note 7, in December 2024, the Company entered into the Lonza Agreement with Lonza to serve as one of the Company's cell processing manufacturing partners. Under the initial work order, Lonza will perform cell therapy manufacturing activities for the CAR-T cell therapy product rese-cel for a term of 12 months with the ability to extend the manufacturing period subject to the terms of the Lonza Agreement. The Lonza Agreement was evaluated under ASC 842 and determined to contain an embedded finance lease commencing in March 2025, resulting in the recognition of a right-of-use asset and lease liability of $14,934. As of December 31, 2025, the Company extended the lease term in accordance with the Lonza Agreement resulting in an increase of the right-of-use asset and lease liability of $6,137.

Summary of leases under ASC 842

The following table contains information pertaining to the Company’s operating and finance leases for the years ended December 31, 2025 and 2024.

Year Ended December 31,

Finance leases

Total fixed finance lease cost $ 14,395 $ 3,850

Operating leases

Total fixed operating lease cost $ 4,211 $ 3,247

Short-term lease cost 34 750

Total operating lease cost $ 4,416 $ 4,293

Cash paid in the measurement of lease liabilities

Operating cash flows used for operating leases $ 4,227 $ 3,291

Operating cash flows used for finance leases 1,713 748

Financing cash flows for finance leases 6,261 897

Other information

Weighted average remaining lease term - finance leases (in years) 1.1 1.7

Weighted average discount rate - finance leases 10.7 % 11.5 %

Weighted average remaining lease term - operating leases (in years) 0.9 1.7

Weighted average discount rate - operating leases 10.3 % 11.0 %

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For finance leases embedded in CDMO arrangements, interest expense is recognized using the effective interest method, applying the Company's incremental borrowing rate as required by ASC 842, and amortization expense is recognized on a straight-line basis over the shorter of the life of the asset or the term of the lease.

Future lease payments under the non-cancelable leases as of December 31, 2025 are as follows:

Finance Leases Operating Leases

Total undiscounted lease payments 25,194 3,633

Less imputed interest (1,557 ) (172 )

10. Common Stock

Common Stock

Pursuant to the Company’s Third Amended and Restated Certificate of Incorporation, as amended, the Company is authorized to issue 293,590,481 shares of voting common stock and 6,409,519 shares of non-voting common stock. In May 2024, the remaining 1,444,295 shares of non-voting common stock were converted to voting common stock and no shares of non-voting common stock are outstanding as of December 31, 2025.

June 2025 Financing

In June 2025, the Company issued (i) 39,200,000 shares of its common stock and accompanying warrants to purchase an aggregate of 39,200,000 shares of common stock (or pre-funded warrants in lieu thereof) and (ii) in lieu of common stock, to certain investors, pre-funded warrants to purchase an aggregate of up to 10,800,000 shares of its common stock and accompanying warrants to purchase an aggregate of 10,800,000 shares of common stock (or pre-funded warrants in lieu thereof), at an exercise price of $0.00001 per pre-funded warrant. An additional 3,090,190 common stock warrants were issued in the financing for shares purchased by the underwriters in the market to cover overallotment demand. The combined offering price of each share of common stock and accompanying common stock warrant was $2.00. The combined offering price of each pre-funded warrant and accompanying common stock warrant was $1.99999. The pre-funded warrants are exercisable immediately. The common stock and pre-funded warrants were sold in combination with an accompanying common stock warrant to purchase one share of common stock (or a pre-funded warrant in lieu thereof) for each share of common stock or pre-funded warrant sold. Each common stock warrant has an exercise price per share of $2.50. The common stock warrants are immediately exercisable from the date of issuance and will expire on September 12, 2026, fifteen months from the date of issuance. Aggregate net proceeds were $93,558 after deducting underwriting discounts and commissions and offering expenses. As of December 31, 2025, 4,800,000 pre-funded warrants had been exercised and 6,000,000 remain outstanding. As of December 31, 2025, no common stock warrants had been exercised and 53,090,190 remain outstanding. Subsequent to December 31, 2025, 2,775,100 common stock warrants were exercised for proceeds of $6,938.

The pre-funded warrants and common stock warrants were classified as a component of permanent stockholders’ equity within additional paid-in capital and were recorded at the issuance date using a relative fair value allocation method. The pre-funded warrants and common stock warrants are equity classified because they (i) are freestanding financial instruments that are legally detachable and separately exercisable from the equity instruments, (ii) are immediately exercisable, (iii) do not embody an obligation for the Company to repurchase its shares, (iv) permit the holders to receive a fixed number of shares of common stock upon exercise, (v) are indexed to the Company’s common stock and (vi) meet the equity classification criteria. In addition, such pre-funded warrants and common stock warrants do not provide any guarantee of value or return.

At-the-Market Offering

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On March 31, 2025, the Company converted the Form S-3ASR to a Form S-3 (File No. 333-278126) by post-effective amendments. This Form S-3 was declared effective on March 31, 2025. The Company had a Sales Agreement with TD Securities (USA) LLC (as successor to Cowen and Company, LLC) (TD Cowen) to provide for the offering, issuance and sale of up to an aggregate amount of $200.0 million of common stock from time to time in “at-the-market” offerings (2024 ATM Program) pursuant to its S-3, and subject to the limitations thereof. On June 11, 2025, the 2024 ATM Program with TD Cowen was terminated. Prior to termination, the Company sold an aggregate of 2,609,865 shares pursuant to the 2024 ATM Program for total net proceeds of $7,724, consisting of $5,129 in 2024 and $2,595 in 2025.

On August 7, 2025, the Company filed a Registration Statement (File No. 333-289339) with the Securities and Exchange Commission (SEC), which was declared effective on August 15, 2025 (2025 Shelf Registration Statement), 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, the Company’s common stock, debt securities or other equity securities in one or more offerings. The Company also simultaneously entered into a Sales Agreement with TD Cowen to provide for the offering, issuance and sale of up to an aggregate amount of $150.0 million of the Company's common stock from time to time in “at-the-market” offerings (the 2025 ATM Program) under the 2025 Shelf Registration Statement and subject to the limitations thereof (the 2025 Sales Agreement). During the year ended December 31, 2025, the Company sold 4,160,176 shares pursuant to the 2025 ATM Program for net proceeds of $10,151. Subsequent to December 31, 2025, the Company sold 8,055,260 additional shares, for net proceeds of $22,568.

2018 Stock Option and Grant Plan

In September 2018, the Company adopted the 2018 Stock Option and Grant Plan (the 2018 Plan), which provided for the Company to sell or issue common stock, or other stock-based awards, to employees, members of the board of directors and consultants of the Company. The Company generally granted stock-based awards with service conditions only (service-based awards), although there was one grant with performance conditions. As of December 31, 2020, there were no unvested options with performance conditions. Stock options granted under the 2018 Plan generally vest over three to four years. A total of 1,959,411 options were granted under the 2018 Plan prior to the Company’s IPO in October 2019. No further grants may be made under the 2018 Plan subsequent to the IPO.

2019 Stock Option and Incentive Plan

The 2019 Stock Option and Incentive Plan (2019 Plan) was approved by the Company’s board of directors on October 14, 2019, and became effective on October 23, 2019. The 2019 Plan provides for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock units, restricted stock awards, unrestricted stock awards, cash-based awards and dividend equivalent rights to the Company’s officers, employees, directors and consultants. The number of shares initially reserved for issuance under the 2019 Plan was 2,342,288, which will be increased each January 1 thereafter by 4% of the number of shares of the Company’s common stock outstanding on the immediately preceding December 31 or such lesser number of shares determined by the Company’s board of directors or compensation committee of the board of directors. On June 1, 2023, at the 2023 Annual Meeting of Stockholders of the Company, the stockholders of the Company approved Amendment No. 1 to the 2019 Plan, increasing the number of shares of common stock reserved for issuance under the 2019 Plan by 3,000,000 shares. On January 1, 2026, the total number of shares under the 2019 Plan was increased by 4,019,172 shares pursuant to the 2019 Plan Evergreen Provision. As of December 31, 2025, there were 1,066,471 shares remaining available for issuance under the 2019 Plan.

2025 Inducement Plan

In October 2025, the Company adopted the 2025 Inducement Plan (Inducement Plan). The Inducement Plan was adopted by the Compensation Committee of the Company’s board of directors without stockholder approval pursuant to Nasdaq Listing Rule 5635(c)(4). In accordance with Rule 5635(c)(4), awards made under the Inducement Plan, including stock options and restricted stock units, may only be granted to newly hired employees as a material inducement to accept employment with the Company. Stock options granted under the Inducement Plan expire no

F-23

later than ten years from the date of grant. The number of shares reserved for issuance under the Inducement Plan was 275,000 shares. As of December 31, 2025, there were no shares available for issuance under the Inducement Plan.

Stock Option Repricing

On May 19, 2025, the Company’s Board of Directors approved the repricing of certain outstanding vested and unvested stock options. Pursuant to the repricing, all options granted under the 2018 Plan and 2019 Plan held by current employees, non-employee directors and certain consultants were repriced to $1.92, the closing price of the Company’s common stock on May 19, 2025, to the extent such options had an exercise price in excess of 1.5x the $1.92 closing price per share. To exercise the repriced options at the reduced exercise price, eligible participants must remain employed with the Company through a retention period of 12 months that begins on May 19, 2025.

As a result of the repricing, 9,900,096 vested and unvested stock options outstanding as of May 19, 2025, with original exercise prices ranging from $2.88 to $23.97, were repriced. The repricing resulted in incremental stock-based compensation expense of $3,021, of which $1,813 related to vested stock option awards and is being amortized over the retention period, and $1,208 related to unvested stock option awards and is being amortized on a straight-line basis over the remaining vesting period of those awards.

Stock Option Activity

A summary of stock option activity is presented below:

(1) The weighted average exercise prices and aggregate intrinsic values in this table will not reflect the impact of the May 2025 repricing until the retention period is complete in May 2026.

The aggregate intrinsic value of options is calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock. The weighted average grant-date fair value of stock options granted during the years ended December 31, 2025 and 2024 was $1.52 and $13.44, respectively.

The fair value of each award is estimated using Black-Scholes based on the following assumptions:

Year Ended December 31,

Expected term 5.5 years—6.1 years 5.5 years—6.2 years

Expected dividend yield 0% 0%

Black-Scholes requires the use of subjective assumptions which determine the fair value of stock-based awards. These assumptions include:

Expected term—The expected term represents the period that stock-based awards are expected to be outstanding. The expected term for option grants is determined using the simplified method, which is the midpoint between the vesting period and the contractual term of the option.

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Expected volatility—Expected volatility is estimated using the Company's stock price since its IPO in October 2019.

Risk-free interest rate—The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of a stock-based award.

Expected dividend—The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero.

Stock-based Compensation

The Company has recorded stock-based compensation in the accompanying statements of operations as follows: