UTHR US Equity☆

uthr-20231231

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2023

OR

For the transition period from to

United Therapeutics Corporation

(Exact Name of Registrant as Specified in Its Charter)

(Address of Principal Executive Offices) (Zip Code)

(301)608-9292

Registrant’s Telephone Number, Including Area Code

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Trading Symbol(s) Name of each exchange on which registered

Common Stock, par value $.01 per share UTHR Nasdaq Global Select Market

Securities registered pursuant to Section 12(g) of the Act:

None

(Title of Class)

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes☒ No ☐

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐No☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer ☒ Accelerated filer ☐

Non-accelerated filer ☐ Smaller reporting company ☐

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒

The aggregate market value of the Common Stock held by non-affiliates of the registrant, based on the closing price on June 30, 2023, as reported by the Nasdaq Global Select Market was approximately $9,138,231,901.

The number of shares outstanding of the issuer’s common stock, par value $0.01 per share, as of February 14, 2024, was 47,058,545.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s definitive proxy statement for the registrant’s 2024 annual meeting of shareholders scheduled to be held on June 26, 2024, are incorporated by reference in Part III of this Form 10-K.

TABLE OF CONTENTS

PART I 3

Item 1. Business 3

Item 1A. Risk Factors 36

Item 1B. Unresolved Staff Comments 48

Item 1C. Cybersecurity 49

Item 2. Properties 50

Item 3. Legal Proceedings 51

Item 4. Mine Safety Disclosures 51

Item 6. [Reserved] 52

Item 7A. Quantitative and Qualitative Disclosures About Market Risk 64

Item 8. Financial Statements and Supplementary Data F-1

Item 9A. Controls and Procedures 65

Item 9B. Other Information 65

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections 66

PART III 66

Item 10. Directors, Executive Officers, and Corporate Governance 66

Item 11. Executive Compensation 68

Item 14. Principal Accountant Fees and Services 70

Item 15. Exhibits and Financial Statement Schedules 70

SIGNATURES 75

2 United Therapeutics, a public benefit corporation

PART I

Item 1. Business

Overview

We build on the strength of our research and development expertise and a distinctive, entrepreneurial culture that encourages diversity, innovation, creativity, sustainability, and, simply, fun. Since inception, our mission has been to find a cure for pulmonary arterial hypertension (PAH) and other life-threatening diseases. Toward this goal we have successfully obtained approval from the U.S. Food and Drug Administration (FDA) for several medicines, we are always conducting new clinical trials, and we are working to create an unlimited supply of manufactured organs for transplantation.

We are the first publicly-traded biotech or pharmaceutical company to take the form of a public benefit corporation (PBC). Our public benefit purpose is to provide a brighter future for patients through (a) the development of novel pharmaceutical therapies; and (b) technologies that expand the availability of transplantable organs. At the same time, we seek to provide our shareholders with superior financial performance and our communities with earth-sensitive energy utilization.

We market and sell the following commercial therapies in the United States to treat PAH: Tyvaso DPI® (treprostinil) Inhalation Powder (Tyvaso DPI); Tyvaso® (treprostinil) Inhalation Solution (nebulizedTyvaso), which includes the Tyvaso Inhalation System; Remodulin® (treprostinil) Injection (Remodulin); Orenitram® (treprostinil) Extended-Release Tablets (Orenitram); and Adcirca® (tadalafil) Tablets (Adcirca). Tyvaso DPI and nebulized Tyvaso are also approved to treat pulmonary hypertension associated with interstitial lung disease (PH-ILD). In the United States, we market and sell an oncology product, Unituxin® (dinutuximab) Injection (Unituxin), which is approved for the treatment of high-risk neuroblastoma, and the Remunity® Pump for Remodulin (Remunity). Outside the United States, we derive revenues from sales of nebulized Tyvaso, Remodulin, and Unituxin.

We are actively advancing a pipeline of research and development projects that includes new indications and delivery devices for our existing products, as well as new products to treat PAH and other conditions. We are also focused on a variety of manufactured organ products with the goal of addressing the chronic shortage of transplantable organs for patients with end-stage organ diseases.

Our principal executive offices are located at 1000 Spring Street, Silver Spring, Maryland 20910 and at 55 T.W. Alexander Drive, Research Triangle Park, North Carolina 27709. Unless the context requires otherwise or unless otherwise noted, all references in this Annual Report on Form 10-K (this Report) to “United Therapeutics” and to the “company”, “we”, “us” or “our” are to United Therapeutics Corporation and its subsidiaries.

Our Commercial Products

Our commercial product portfolio consists of the following:

Product Mode of Delivery Indication Current Status Our Territory

Orenitram Oral tablets PAH Commercial sales in the U.S. Worldwide

Adcirca Oral tablets PAH Commercial sales in the U.S. United States

* In Japan, nebulized Tyvaso is currently only approved to treat PAH.

** Remodulin is marketed and sold in most of the major European markets other than the United Kingdom for both intravenous and subcutaneous administration.

Products to Treat Pulmonary Hypertension

Pulmonary hypertension (PH) has been classified into five groups. PAH is designated as group 1 PH, which includes multiple etiologies such as idiopathic (meaning the cause is unknown) and heritable PAH, as well as PAH associated with connective tissue diseases. PH associated with lung disease, such as PH-ILD, has been classified as group 3 PH. In addition, patients with PAH are classified into classes based on clinical severity, ranging from functional class I (no symptoms) through functional class IV (severe symptoms). Labeled indications for PAH therapies often note that clinical studies for the drug predominantly included patients in one or more functional classes.

Our PH products were initially approved to treat only PAH. In March 2021, nebulized Tyvaso was approved to treat PH-ILD in addition to PAH. In May 2022, we also obtained FDA approval of Tyvaso DPI to treat both PAH and PH-ILD. We are engaged in further research and development of additional indications for Tyvaso DPI and nebulized Tyvaso to treat certain fibrotic lung conditions underlying PH-ILD. For further details, see Research and Development below.

PAH is a life-threatening disease that affects the blood vessels in the lungs and is characterized by increased pressure in the pulmonary arteries, which are the blood vessels leading from the heart to the lungs. The elevated pressure in the pulmonary arteries strains the right side of the heart as it pumps blood to the lungs. This eventually leads to right heart failure and, ultimately, death. PAH is characterized by structural changes in blood vessel walls, aggregation of platelets, and alteration of smooth muscle cell function. We believe that PAH affects about 500,000 individuals worldwide. We have seen increases in the number of people diagnosed with the disease, but due to the rarity of the disease and the complexity of diagnosing it, only a small fraction of patients with PAH are being treated.

Current therapies approved by the FDA for PAH focus on three distinct molecular pathways: the prostacyclin pathway, the nitric oxide pathway, and the endothelin pathway. The classes of drugs that target these three pathways are:

•Prostacyclin Analogues and IP Prostacyclin Receptor Agonists. Patients with PAH have been shown to have reduced levels of prostacyclin, a naturally occurring molecule that relaxes the pulmonary blood vessels, prevents platelet aggregation, and inhibits the proliferation of smooth muscle cells in the pulmonary vessels. Drugs that mimic the action of prostacyclin, known as prostacyclin analogues, are established PAH treatments. Another class of therapy, called IP prostacyclin receptor agonists, also addresses PAH through the prostacyclin pathway. As compared with prostacyclin analogues, which broadly mimic the effect of prostacyclin, IP prostacyclin receptor agonists bind selectively to (and activate) the IP receptor, one of several prostacyclin receptors.

•Phosphodiesterase Type 5 (PDE-5) Inhibitors and Soluble Guanylate Cyclase (sGC) Stimulators. Patients with PAH have also been shown to have reduced levels of the enzyme responsible for producing nitric oxide, a naturally occurring substance in the body that causes relaxation of the pulmonary blood vessels. Nitric oxide produces this effect by increasing intracellular levels of cyclic guanosine monophosphate GMP (cyclic GMP). Therefore, another established therapeutic approach has been to inhibit the degradation of cyclic GMP using drugs known as PDE-5 inhibitors. In addition, sGC is an enzyme found in the endothelial cells and the receptor for nitric oxide. When nitric oxide binds to sGC, the enzyme enhances production of cyclic GMP. As a result, sGC stimulators are also approved to treat PAH.

•Endothelin Receptor Antagonists. PAH patients have also been shown to have elevated levels of endothelin-1, a naturally occurring peptide in the body that causes constriction of, and structural changes to, the pulmonary blood vessels. Therefore, another established therapeutic approach has been to block the action of endothelin with drugs that are known as endothelin receptor antagonists (ERAs).

Because any or all of the three pathways may be therapeutic targets in a patient, these classes of drugs are used alone or in combination to treat patients with PAH. We currently market drugs in two of these classes. Tyvaso DPI, nebulized Tyvaso, Remodulin, and Orenitram are all formulations of treprostinil, a prostacyclin analogue, and Adcirca is a PDE-5 inhibitor.

New drugs are also in development to treat PAH via additional pathways. The most advanced among these is sotatercept, an investigational activin signaling inhibitor being developed by Merck & Co., Inc. (Merck) for the treatment of PAH through the transforming growth factor-beta (TGF-beta) signaling pathway. Merck has filed a new drug application (NDA) with the FDA for sotatercept and has announced a Prescription Drug User Fee Act (PDUFA) target action date of March 26, 2024.

PH-ILD is also a rare condition, impacting at least 30,000 patients in the United States. Tyvaso DPI and nebulized Tyvaso are the only available therapies the FDA has approved to treat PH-ILD.

Tyvaso DPI and Nebulized Tyvaso

Tyvaso was initially approved as a nebulized product by the FDA to treat PAH and was launched commercially in the United States in 2009. Following the successful INCREASE study of nebulized Tyvaso in patients with PH-ILD, including patients with underlying idiopathic pulmonary fibrosis (IPF) and combined pulmonary fibrosis and emphysema, the FDA approved our efficacy supplement to the nebulized Tyvaso NDA in March 2021. As a result, nebulized Tyvaso’s label was updated to include the PH-ILD indication. In May 2022, the FDA approved our dry powder formulation of inhaled treprostinil called Tyvaso DPI, for the treatment of both PAH and PH-ILD. We developed this product under an in-license from MannKind Corporation (MannKind) and launched this product commercially in the United States in June 2022.

4 United Therapeutics, a public benefit corporation

We sell Tyvaso DPI and nebulized Tyvaso to specialty pharmaceutical distributors in the United States. We recognized $1,233.7 million, $873.0 million, and $607.5 million in combined Tyvaso DPI and nebulized Tyvaso net product sales, representing 53 percent, 45 percent, and 36 percent of our total revenues for the years ended December 31, 2023, 2022, and 2021, respectively. Nebulized Tyvaso is approved and commercialized in the United States, Israel, and Argentina to treat PAH and PH-ILD. Nebulized Tyvaso was also approved to treat PAH in Japan in late 2022, and our Japanese distributor, Mochida Pharmaceutical Co., Ltd. (Mochida), launched commercial sales in Japan during the second quarter of 2023. In December 2023, Mochida submitted a marketing authorization application to expand the label for nebulized Tyvaso in Japan to include the treatment of PH-ILD.

Tyvaso DPI is a drug-device combination product that incorporates the dry powder formulation technology and Dreamboat® inhalation device technology used in MannKind’s Afrezza® (insulin human) Inhalation Powder product which was approved by the FDA in 2014 to treat patients with diabetes. We believe that this new inhaled treprostinil therapy provides substantial lifestyle benefits to PAH and PH-ILD patients, as compared with nebulized Tyvaso therapy, because it is: (1) less time-consuming to administer and easier to maintain, as the device is provided in pre-filled, single-use, disposable cassettes, eliminating the need for cleaning and filling; and (2) mobile and more convenient, as the compact design of the inhaler and drug cassettes used with Tyvaso DPI enables the device to easily fit into the patient’s pocket and the device does not require electricity to function.

Nebulized Tyvaso is administered four times a day using our proprietary Tyvaso Inhalation System, which consists of an ultrasonic nebulizer and related accessories. Dose titration is achieved by varying the number of breaths per treatment session typically starting at three breaths per session, and increasing the dose in three-breath increments during the titration process. A single ampule containing nebulized Tyvaso solution is emptied into the Tyvaso Inhalation System once per day, so the Tyvaso Inhalation System only needs to be cleaned once daily. Nebulized Tyvaso is regulated by the FDA as a drug-device combination product consisting of Tyvaso drug product and the Tyvaso Inhalation System. The Tyvaso Inhalation System is classified by the Centers for Medicare and Medicaid Services (CMS) as durable medical equipment.

For newly-diagnosed PAH patients, nebulized Tyvaso and Tyvaso DPI are the only FDA-approved inhaled prostacyclin analogues available in the United States. The manufacturer of another inhaled prostacyclin analogue, Ventavis® (iloprost), announced in October 2023 that its associated nebulizer had been discontinued and encouraged healthcare providers to explore alternative treatments for patients utilizing Ventavis and refrain from initiating new patients on Ventavis.

Studies establishing the effectiveness of nebulized Tyvaso to treat PAH included predominately PAH patients with functional class III symptoms (patients who may not have symptoms at rest but whose activities are greatly limited by shortness of breath, fatigue, or near fainting). Nebulized Tyvaso was generally well tolerated in these trials. The most common side effects were transient cough, headache, nausea, dizziness, and flushing. In January and June 2021, data from the INCREASE study of nebulized Tyvaso for PH-ILD were published in the New England Journal of Medicine and The Lancet Respiratory Medicine, respectively.

In August 2018, we settled patent litigation with Watson Laboratories, Inc. (Watson) related to its abbreviated new drug application (ANDA) seeking FDA approval to market a generic version of nebulized Tyvaso in the United States. Under the terms of this settlement, Watson may launch its generic version of nebulized Tyvaso in the United States beginning in January 2026, although Watson may be permitted to enter the market earlier under certain circumstances. For further detail, see the section below entitled Patents and Other Proprietary Rights, Strategic Licenses, and Market Exclusivity—Generic Competition and Challenges to our Intellectual Property Rights.

Remodulin

Remodulin was approved by the FDA for subcutaneous and intravenous administration in 2002 and 2004, respectively, and has been sold commercially in the United States since 2002. We sell Remodulin to specialty pharmaceutical distributors in the United States and to pharmaceutical distributors internationally. We recognized $494.8 million, $500.2 million, and $513.7 million in Remodulin net product sales, representing 21 percent, 26 percent, and 31 percent of our total revenues for the years ended December 31, 2023, 2022, and 2021, respectively. Remodulin is indicated to treat patients with PAH to diminish symptoms associated with exercise. Studies establishing effectiveness included patients with functional class II-IV (moderate to severe) symptoms. Outside of the United States, Remodulin is marketed and sold for the treatment of PAH throughout most of Europe, Canada, Mexico, and various countries throughout Asia, the Middle East, and South America, as noted in the table above.

We believe that Remodulin has many qualities that make it an appealing alternative to competitive therapies. Remodulin is stable at room temperature, so it does not need to be cooled during infusion and patients do not need to use cooling packs or refrigeration to keep it stable. Treprostinil is highly soluble under certain circumstances and highly potent, which enables us to manufacture Remodulin in concentrated solutions. This allows therapeutic concentrations of Remodulin to be delivered at low flow rates via miniaturized infusion pumps for both subcutaneous and intravenous infusion. Remodulin can be continuously infused for up to 72 hours before refilling the external infusion pump, or up to 48 hours for diluted Remodulin. This profile contrasts favorably with non-treprostinil based, continuously-infused prostacyclin therapies on the market: Flolan®; Veletri®; and generic epoprostenol.

Flolan and generic epoprostenol are not stable at room temperature (and therefore require refrigeration or the use of cooling packs), but Veletri may be stable at room temperature depending on its concentration. Flolan, generic epoprostenol, and Veletri have shorter half-lives than Remodulin, requiring mixing prior to pump refills. None of these competitive products may be administered via subcutaneous infusion, and therefore may only be delivered intravenously which, unlike subcutaneous infusion, requires intravenous infusion line placement and carries the risk of serious bloodstream infection.

We also face competition from manufacturers of generic versions of Remodulin in the United States and abroad. See the section below entitled Patents and Other Proprietary Rights, Strategic Licenses, and Market Exclusivity—Generic Competition and Challenges to our Intellectual Property Rights.

Patients must use external pumps manufactured by third parties to deliver Remodulin. Historically, Smiths Medical, Inc. (Smiths Medical, which was acquired by ICU Medical, Inc., or ICU Medical) manufactured the pumps used by most patients in the United States to administer Remodulin, including the CADD-MS®3 (MS-3) pump used to deliver subcutaneous Remodulin, and the CADD-Legacy® pump to deliver intravenous Remodulin. In 2015, Smiths Medical notified us that it was planning to discontinue the manufacture of the MS-3 pumps and associated cartridges. In response, we funded Smiths Medical’s manufacture of several thousand additional MS-3 pumps and, in parallel, pursued development of the Remunity Pump to help ensure that PAH patients would not experience a delay or disruption in their Remodulin therapy. The inventory of MS-3 pumps held by specialty pharmacy distributors (including the additional pumps we funded the manufacture of) is now exhausted. In June 2023, our third-party contract manufacturer, Gilero, LLC (Gilero), obtained FDA clearance for a cartridge to be used with the MS-3 pump for subcutaneous infusion of Remodulin. ICU Medical has also discontinued the CADD-Legacy system, and has made an alternative pump, the CADD-SolisTM, available for administration of intravenous Remodulin. In addition to the Remunity Pump, which we launched in 2021 to administer subcutaneous Remodulin, we are developing another next-generation delivery system for intravenous delivery of Remodulin.

There are serious side effects associated with Remodulin. For example, when infused subcutaneously, Remodulin causes varying degrees of infusion site pain and reaction (redness and swelling) in most patients. Patients who cannot tolerate the infusion site pain related to the use of subcutaneous Remodulin may instead use intravenous Remodulin. Intravenous Remodulin is delivered continuously through a surgically implanted central venous catheter, similar to Flolan, Veletri, and generic epoprostenol. Patients who receive therapy through implanted venous catheters have a risk of developing bloodstream infections and a serious systemic infection known as sepsis. Other common side effects associated with both subcutaneous and intravenous Remodulin include headache, diarrhea, nausea, jaw pain, vasodilation, and edema.

Remodulin may require dilution prior to administration based on factors such as patient weight, desired dose, and desired infusion rate. Dilution may be performed with multiple approved sterile diluent solutions, as specified in the full prescribing information. To provide patients with a reliable supply of diluent solution, we manufacture and distribute Sterile Diluent for Remodulin, a high-pH glycine diluent.

Remunity Pump

In February2021, we launched limited commercial sales of the Remunity Pump, which is a semi-disposable system for subcutaneous delivery of treprostinil that we developed in collaboration with DEKA Research & Development Corp. (DEKA) under an exclusive development and license agreement. The Remunity Pump consists of a small, lightweight, durable pump and controller designed to have a service life of at least three years. The Remunity Pump uses disposable cassettes filled with Remodulin, which can be connected to the pump with less patient manipulation than is typically involved in filling other currently-available subcutaneous pumps. In November 2019, we entered into a supply agreement with an affiliate of DEKA to manufacture and supply the Remunity Pump to us. Under the terms of the agreement, we reimburse all of DEKA’s and its affiliates’ costs to manufacture the Remunity Pump.

The Remunity Pump was initially made available to patients in weekly shipments of disposable cassettes that were pre-filled with Remodulin by our specialty pharmacy distributors. In September 2022, we launched a patient-filled version of the Remunity Pump, which enables patients to receive monthly shipments of empty, ready-to-fill Remunity cassettes and Remodulin. The majority of patients being treated with subcutaneous Remodulin in the United States are now using the Remunity Pump. The Remunity Pump is classified by CMS as durable medical equipment.

Orenitram

Orenitram is the only FDA-approved, orally-administered prostacyclin analogue, and is the only oral PAH prostacyclin class therapy approved in the United States that is titratable to a maximum tolerated dose without a dose ceiling. We sell Orenitram to the same specialty pharmaceutical distributors in the United States that distribute Tyvaso DPI, nebulized Tyvaso, and Remodulin. We recognized $359.4 million, $325.1 million, and $306.1 million in Orenitram net product sales, representing 15 percent, 17 percent, and 18 percent of our total revenues for the years ended December 31, 2023, 2022, and 2021, respectively. In 2013, the FDA approved Orenitram for the treatment of PAH patients to improve exercise capacity. The primary study that supported efficacy of Orenitram was a 12-week monotherapy study in which PAH patients were not on any approved background PAH therapy. In August 2018, we announced that our clinical study of Orenitram called FREEDOM-EV had met its primary endpoint of delayed time to first clinical worsening event. In particular, the preliminary results showed that Orenitram, when taken with an oral PAH background therapy, decreased the risk of a clinical worsening event versus

6 United Therapeutics, a public benefit corporation

placebo by 25 percent (p=0.0391), driven by a 61 percent decrease in the risk of disease progression for patients taking Orenitram, when compared to placebo (p=0.0002). In October 2019, the FDA approved a supplement to the Orenitram NDA to update the product’s label to reflect the FREEDOM-EV results. As a result, Orenitram is indicated to delay disease progression and improve exercise capacity.

Secondary endpoints in the FREEDOM-EV study included changes from baseline in six-minute walk distance (6MWD), Borg dyspnea score (shortness of breath test), functional class, NT-proBNP levels, and combined 6MWD and Borg dyspnea score. Secondary endpoint data, which are not included in the updated FDA-approved labeling, are summarized below:

•Change in 6MWD: The median 6MWD trended toward improvement at week 24 (Hodges-Lehmann treatment estimate: seven meters). Median 6MWD improved with Orenitram at weeks 36 (13 meters) and 48 (21 meters) compared to placebo.

•Change in Borg dyspnea score and WHO functional class:When classified categorically as “improved,” “no change,” or “deteriorated,” participants in the Orenitram group exhibited a significantly positive shift in Borg dyspnea score and WHO functional class compared to placebo at weeks 24, 36, and 48.

•Change in NT-proBNP levels:NT-proBNP levels were significantly improved with Orenitram at weeks 24 and 36. Per the study protocol, NT-proBNP was not assessed at week 48.

•Change in combined 6MWD and Borg dyspnea score: Combined 6MWD and Borg dyspnea score was significantly improved with Orenitram when assessed at week 24 compared to placebo.

Sixty-eight percent of the initial FREEDOM-EV participants enrolled in an open-label extension (OLE) study to further assess Orenitram’s tolerability, efficacy, and survival. Participants randomized to placebo in the initial FREEDOM-EV study who initiated Orenitram therapy after clinical worsening and tolerated treatment through week 48 demonstrated 6MWD improvement of 84 meters (p<0.0001), favorable shifts in functional class (p<0.0001), and a reduction in NT-proBNP of 778 pg/mL (p=0.03), compared to OLE baseline. Modest trends toward benefit were also measured at week 48 for those initially assigned placebo who did not have clinical worsening. Patients initially assigned to the active Orenitram group who did not have clinical worsening and who continued Orenitram during the OLE study were stable at week 48. Mortality rates were similar between Orenitram and placebo groups at the end of randomized treatment. However, in participants for whom data are available (89 percent), Orenitram was associated with a 36 percent decreased risk of mortality compared with placebo at study closure (p=0.013). These mortality data are not reflected in the FDA-approved labeling because they include data accrued in the OLE study.

In 2020, we published the results of a retrospective study in which a competing therapy, selexipag, was associated with 67 percent higher PAH-associated healthcare costs on average, during the first six months of therapy, compared to Orenitram. Selexipag and Orenitram are the only FDA-approved oral prostacyclin-class therapies.

The studies that established efficacy included predominately patients with functional class II-III symptoms and etiologies of idiopathic or heritable PAH (66 percent) or PAH associated with connective tissue disease (26 percent). The most common side effects observed in our clinical studies were headache, nausea, and diarrhea. Orenitram is currently only approved in the United States.

In February 2018, we settled patent litigation with Actavis Laboratories FL, Inc. (Actavis) related to its ANDA seeking FDA approval to market a generic version of Orenitram in the United States. Under the terms of this settlement, Actavis may launch its generic version of Orenitram in the United States beginning in June 2027, although Actavis may be permitted to enter the market earlier under certain circumstances. In May 2022, we settled litigation with ANI Pharmaceuticals, Inc. (ANI) regarding its ANDA seeking FDA approval to market a generic version of Orenitram. Under the settlement agreement, ANI can market its generic version of Orenitram in the United States beginning in December 2027, although it may be permitted to enter the market earlier under certain circumstances. For further detail, see the section below entitled Patents and Other Proprietary Rights, Strategic Licenses, and Market Exclusivity—Generic Competition and Challenges to our Intellectual Property Rights.

Adcirca

Adcirca is a PDE-5 inhibitor, the active pharmaceutical ingredient of which is tadalafil. Tadalafil is also the active pharmaceutical ingredient in Cialis®, which is marketed by Eli Lilly and Company (Lilly) for the treatment of erectile dysfunction. We acquired the commercial rights to Adcirca for the treatment of PAH in the United States from Lilly in 2008. We sell Adcirca at prices established by Lilly. We recognized $28.9 million, $41.3 million, and $55.9 million in Adcirca net product sales, representing one percent, two percent, and three percent of our total revenues for the years ended December 31, 2023, 2022, and 2021, respectively.

In 2009, the FDA approved Adcirca with a recommended dose of 40 mg, making it the only once-daily PDE-5 inhibitor for the treatment of PAH. Adcirca is indicated to improve exercise ability in patients with PAH. Studies establishing effectiveness included predominately patients with functional class II-III symptoms. Headaches were the most commonly reported side effect.

In August 2018, Mylan N.V. announced the launch of its generic version of Adcirca, which resulted in a material adverse impact on Adcirca net product sales. Additional companies launched generic versions of Adcirca in February 2019. The

current term of our Adcirca license agreement expires December 31, 2026. For further detail, see the section below entitled Patents and Other Proprietary Rights, Strategic Licenses, and Market Exclusivity—Generic Competition and Challenges to our Intellectual Property Rights.

Product to Treat Cancer — Unituxin

In March 2015, the FDA approved our Biologics License Application (BLA) for Unituxin, in combination with granulocyte-macrophage colony-stimulating factor, interleukin-2, and 13-cis-retinoic acid, for the treatment of patients with high-risk neuroblastoma (a rare form of pediatric cancer) who achieve at least a partial response to prior first-line multiagent, multimodality therapy. Unituxin is a chimeric monoclonal antibody composed of a combination of mouse and human DNA that induces antibody-dependent cell-mediated cytotoxicity, a mechanism of cell-mediated immunity whereby the immune system actively targets a cell that has been bound by specific antibodies. Unituxin therapy is associated with severe side effects, including infections, infusion reactions, hypokalemia, hypotension, pain, fever, and capillary leak syndrome. In November 2018, we received approval from Health Canada to market Unituxin, and we launched commercial sales of the product in Canada in late 2019. In June 2021, our Japanese distributor, Ohara Pharmaceutical Co., Ltd. (Ohara), obtained approval to market Unituxin in Japan and launched commercial sales shortly thereafter.

We recognized $198.9 million, $182.9 million, and $202.3 million in Unituxin net product sales, representing nine percent, nine percent, and 12 percent of our total revenues for the years ended December 31, 2023, 2022, and 2021, respectively.

Research and Development

We focus our research and development efforts on the following pipeline programs. We also engage in a variety of additional research and development efforts, including technologies designed to increase the supply of transplantable organs and tissues and improve outcomes for transplant recipients through xenotransplantation, regenerative medicine, bio-artificial organs, three-dimensional (3-D) organ bioprinting, and ex vivo lung perfusion.

Select Pipeline Programs

Product Mode of Administration Indication Current StatusSTUDY NAME Our Territory

Nebulized Tyvaso (treprostinil) Inhaled PPF Phase 3 TETON PPF study Worldwide

Nebulized Tyvaso — TETON studies

We are enrolling two phase 3 studies, called TETON 1 and TETON 2, of nebulized Tyvaso for the treatment of IPF. TETON 1 is being conducted in the United States and Canada, and TETON 2 is being conducted outside the United States and Canada. We are targeting enrollment of 576 patients in each study. The primary endpoint of both studies is the change in absolute forced vital capacity (FVC) from baseline to week 52. The TETON 1 study enrolled its first patient in June 2021, and the TETON 2 study enrolled its first patient in October 2022. We are also enrolling a phase 3 study of nebulized Tyvaso called TETON PPF for the treatment of progressive pulmonary fibrosis (PPF); we enrolled the first patient in TETON PPF in October 2023.

The TETON 1 and TETON 2 studies were prompted by data from the INCREASE study of nebulized Tyvaso for the treatment of PH-ILD, which demonstrated improvements in certain key parameters of lung function in pulmonary hypertension patients with fibrotic lung disease (improved absolute FVC and reduced exacerbations of underlying lung disease). Specifically, in the INCREASE study, treatment with nebulized Tyvaso resulted in significant improvements in percent predicted FVC at weeks 8 and 16, with subjects having an underlying etiology of IPF showing the greatest improvement (week 8: 2.5 percent; p=0.0380 and week 16: 3.5 percent; p=0.0147). In May 2022, data from the INCREASE OLE study were presented at a medical conference, indicating that improvements in FVC were sustained for at least 64 weeks for PH-ILD patients with underlying IPF. For those patients who received placebo during the INCREASE study, marked improvements in FVC were observed following transition to nebulized Tyvaso during the OLE study. These data points, combined with substantial preclinical evidence of antifibrotic activity of treprostinil, suggest that nebulized Tyvaso may offer a treatment option for patients with IPF. We believe there are approximately 100,000 IPF patients in the United States.

The TETON PPF study was also prompted by data from the INCREASE study. PPF is a group of ILD conditions that exhibit progressive, self-sustaining fibrosis, and a similar disease course to IPF. PPF includes idiopathic interstitial pneumonias, autoimmune ILDs, chronic fibrosing hypersensitivity pneumonitis, and fibrotic ILDs related to environmental/occupational exposure. Due to the similarities in the mechanism of fibrosis between IPF and PPF, we anticipate that anti-fibrotic therapies

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will impact disease progression similarly in patients with these conditions. Therefore, based on the FVC improvements in subjects with IPF observed in the INCREASE study, we are conducting a single pivotal study, TETON PPF, to evaluate the safety and efficacy of nebulized Tyvaso for the treatment of PPF. We are targeting enrollment of 698 patients in this study. We believe there are up to 60,000 PPF patients in the United States.

In December 2020, the FDA granted orphan designation for treprostinil to treat IPF. In March 2022, the European Medicines Agency also granted orphan designation for treprostinil to treat IPF. If the TETON studies are successful, we also plan to seek FDA approval to expand the Tyvaso DPI label to include IPF and PPF, following completion of any FDA-required bridging studies.

In September 2023, the data monitoring committee for the TETON 1 and TETON 2 studies completed a routine, unblinded safety review of data from nearly 550 patients enrolled in these studies, and unanimously recommended continuation of both trials without modification.

Ralinepag

Ralinepag is a next-generation, once-daily, oral, selective, and potent prostacyclin receptor agonist that we are developing for the treatment of PAH. A phase 2 study of ralinepag in 61 PAH patients (40 patients on active ralinepag, 21 on placebo) met its primary endpoint, showing a 29.8 percent reduction (p=0.03) in median pulmonary vascular resistance (PVR, the force or resistance that blood encounters as it flows through the blood vessels in the lungs) after 22 weeks of treatment with ralinepag compared with placebo. After participation in phase 2, 45 patients entered into an OLE study to further determine if ralinepag may be safe and effective for long-term use to treat patients with PAH. The study found that ralinepag had a manageable side effect profile, with a decrease in side effects for patients who continued taking ralinepag over time. Moreover, two years after entering the OLE study, the study showed that ralinepag improved the ability to exercise as the 6MWD significantly increased by a mean of 36.3 meters (p=0.004), and over 85 percent of patients remained stable in their functional class. Additionally, hemodynamic measures (metrics to measure how well the heart is working) taken either one or two years after entering the OLE study demonstrated significant improvements (p=0.05) in both median PVR and mean pulmonary arterial pressure (the pressure in the blood vessels connecting the heart).

We are enrolling ADVANCE OUTCOMES, which is a phase 3, event-driven study of ralinepag in PAH patients with a primary endpoint of time to first clinical worsening event. ADVANCE OUTCOMES is a global, multi-center, placebo-controlled trial that includes patients on approved oral background PAH therapies. During the first quarter of 2023, we discontinued a separate phase 3 study of ralinepag called ADVANCE CAPACITY, due to slow enrollment and a redirection of our internal resources toward the TETON PPF study. In October 2023, the data monitoring committee for the ADVANCE OUTCOMES study completed a routine, unblinded safety review of data from nearly 510 patients enrolled in the study, and unanimously recommended continuation of the trial without modification. The study is targeting enrollment of 700 to 1,000 patients, with the precise number depending on the pace of accruing clinical worsening events.

If approved and launched, we expect ralinepag’s once-daily dosing profile to position it favorably compared with Uptravi (selexipag), which is a twice-daily IP-receptor agonist marketed by Johnson & Johnson for the treatment of PAH. In 2023, Johnson & Johnson reported global sales of Uptravi of nearly $1.6 billion, including over $1.3 billion in U.S. sales, reflecting a growth rate of approximately 20% over 2022.

Organ Manufacturing

Each year, end-stage organ failure kills millions of people. A significant number of these patients could have benefited from an organ transplant. Unfortunately, the number of usable, donated organs available for transplantation has not grown significantly over the past half century, while the need has soared. Our long-term goals are aimed at addressing this shortage. With advances in technology, we believe that creating an unlimited supply of tolerable manufactured organs is now principally an engineering challenge, and we are dedicated to finding engineering solutions. We are engaged in research and development of a variety of technologies designed to increase the supply of transplantable organs and tissues and to improve outcomes for transplant recipients through xenotransplantation, regenerative medicine, 3-D organ bioprinting, bio-artificial organs, and ex vivo lung perfusion.

While we continue to develop and commercialize therapies for rare and life-threatening conditions, we view organ manufacturing as a complementary solution for a broad array of diseases, many of which (such as PAH and PH-ILD) have proven incurable to date despite the availability of pharmaceutical and biologic therapies. For this reason, we included the development of “technologies that expand the availability of transplantable organs” as part of our express public benefit purpose when we converted United Therapeutics to a PBC in 2021.

Xenotransplantation

Our xenotransplantation program includes three development-stage organ products known as “xenografts”, which are intended to be xenotransplanted from genetically modified pigs into humans.

The UHeartTM is a development-stage heart from a pig with ten genetic modifications to support organ functioning in the human body. Six human genes were added to the pig genome to facilitate immune acceptance of the organ, while four genes were removed or “knocked out”: three that contribute to porcine organ rejection in humans and one that can cause organ growth beyond what is normal for humans. The UKidneyTM is a kidney from the same pig with ten gene modifications.

The UThymoKidneyTM is a development-stage kidney from a pig with a single genetic modification, together with tissue from the pig’s thymus. The pig’s thymus tissue is intended to condition the recipient’s immune system to recognize the UThymoKidney as “self” and reduce the likelihood of rejection. The single gene that is inactivated in the pig is responsible for the synthesis of alpha-gal, a sugar on the surface of cells that can cause the immediate rejection of an organ when transplanted into the human body. Because tissues from pigs containing this modification do not contain detectable levels of the alpha-gal sugar, we refer to materials derived from this pig as GalSafe®. In December 2020, the GalSafe pig was approved by the FDA for use as human food or as a potential source for biomedical purposes. Meat from GalSafe pigs is currently being produced for individuals with alpha-gal syndrome, an allergy to meat caused by a bite from the lone star tick. This approval marked only the second FDA approval of a genetically modified animal as a source of food, and the first such approval for a mammal.

We have entered into agreements with Johns Hopkins University (JHU), New York University (NYU), the University of Alabama at Birmingham (UAB), and the University of Maryland, Baltimore (UMB) to perform preclinical testing of our porcine xenografts, with the goal of commencing human clinical trials in the near term. These collaborations have been generating data regarding our UHearts, UKidneys, and UThymoKidneys. In addition to evaluating our xenografts in animal models, our research efforts have used innovative preclinical human models to obtain insights into how xenografts function inside the human body. We continue to share knowledge learned from these experiments with the FDA in advance of beginning human clinical trials.

In February 2024, we inaugurated a clinical-scale, designated pathogen-free (DPF) facility in Virginia and are working toward populating the facility with animals during the first quarter of 2024. When fully operational, we expect this DPF to supply cGMP-compliant xenografts for human clinical trials, with a target capacity of up to 125 organs per year. This facility cost approximately $75 million to construct. We are planning to build additional cGMP DPF facilities at commercial scale, each with target capacities of approximately 1,000 organs per year. While these projects will be capital intensive, the timing and volume of these expenditures will be staggered and paced in a manner intended to balance our need to address market demand as soon as possible following launch with the need to defer the most significant capital expenditures until we achieve certain clinical trial milestones.

Key accomplishments in our xenotransplantation program include the following:

•First Successful Xenotransplants of Porcine Hearts: University of Maryland School of Medicine (UMSOM) surgeons have successfully transplanted UHearts into two living human patients. These procedures were authorized by the FDA on a single-patient, expanded access (also called “compassionate use”) basis. The FDA’s compassionate use regulations allow a physician to apply to use an unapproved product outside of a clinical trial to treat an individual patient with a serious or immediately life-threatening disease or condition when no satisfactory alternative therapy is available. The first patient, transplanted in January 2022, survived for approximately two months with the UHeart. In June 2022, data from this procedure were published in the New England Journal of Medicine. The second patient, transplanted in September 2023, survived for approximately six weeks with the UHeart. We and our collaborators continue to evaluate data from these human transplants.

•Successful UKidney and UHeart Tests in Preclinical Human Models: In 2021, surgeons at NYU and UAB tested UThymoKidneys and UKidneys from our genetically modified pigs in brain-dead organ donors maintained on artificial support, providing preclinical evidence that genetically modified pig organs could transcend the most proximate immunological barriers to xenotransplantation. These studies using a preclinical human decedent model were conducted in brain-dead organ donors whose organs were determined to be ineligible for donation, with the consent of the donor’s family. Results of the UAB experiments were published in the American Journal of Transplantation in January 2022 and the Journal of Clinical Investigation in January 2024, and results of the NYU experiments were published in the New England Journal of Medicine in May 2022.

In June and July 2022, NYU surgeons tested two UHearts from our genetically modified pigs in brain-dead organ donors maintained on artificial support. In each case, normal function was observed for our UHearts over a three-day study period, without signs of early rejection. The results were published in Nature Medicine in July 2023.

In September 2023, NYU surgeons completed a 61-day study of a UThymoKidney in a brain-dead organ donor maintained on artificial support. This experiment marked the longest documented case of a xenotransplanted organ functioning in a human body. Publications of the result of this experiment are expected in the near term.

Regenerative Medicine, Bio-Artificial Organs, and 3-D Organ Bioprinting

•ULobeTM. The ULobe is a development-stage engineered lung lobe made using a porcine lung scaffold that is decellularized and then re-cellularized with cells from a human donor other than the recipient (also called “allogeneic” cells). In 2023, our Regenerative Medicine Laboratory in Research Triangle Park, North Carolina produced 450 decellularized lung scaffolds, 220 recellularized lungs, and 1.7 trillion human cells for use in recellularization.

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•ULungTM. The ULung is a development-stage engineered lung composed of a 3-D printed lung scaffold cellularized with either allogeneic human lung cells, or the patient’s own cells (known as “autologous” cells), with the goal of reducing or eliminating the need for immunosuppression. The lung scaffold used in the ULung is printed using 3-D printers being developed in collaboration with 3D Systems, Inc. Our Organ Manufacturing Group located in Manchester, New Hampshire, has achieved recognition for developing the world’s most complex 3-D printed object. Its lung scaffold designs consist of a record 44 trillion voxels that lay out 4,000 kilometers of pulmonary capillaries and 200 million alveoli, which demonstrate gas exchange in preclinical models. Under our agreement with 3D Systems, we also have the exclusive right to develop additional human solid organs using 3D Systems’ printing technology.

•Miromatrix Medical. In December 2023, we completed the acquisition of Miromatrix Medical Inc. (Miromatrix), a company based in Minnesota, focused on the development of new technologies for generating manufactured kidneys and livers composed of human primary cells. The Miromatrix external liver assist product, called miroliverELAP®, uses a decellularized porcine liver matrix that has been seeded with human-derived cells and an extracorporeal blood circuit to maintain liver support in patients experiencing acute liver failure. Miromatrix first used its decellularization technology to successfully develop two acellular products, MiroMesh® and MiroDerm®, which received FDA 510(k) clearance for hernia repair and wound care applications, respectively, and which were later spun off by Miromatrix. In January 2024, the FDA cleared the Miromatrix IND for miroliverELAP, and we are planning to commence enrollment of a phase 1 study in patients with acute liver failure in 2024. We expect this study will be the first human clinical trial of a manufactured organ. Miromatrix is also developing miroliver®, a fully-implantable manufactured liver product, and mirokidney®, a fully implantable manufactured kidney product, both of which are based on decellularized porcine organ scaffolds that have been reseeded with human-derived cells. Initially the Miromatrix products are intended to be allogeneic, requiring the use of standard immunosuppression protocols. Future versions may be based on autologous cells, reducing or eliminating the need for immunosuppression drugs.

•IVIVA Medical. In October 2023, we completed the acquisition of IVIVA Medical, Inc. (IVIVA), a preclinical stage company based in Massachusetts, focused on bio-artificial manufactured kidney products. IVIVA’s preclinical implantable kidney product uses autologous cells to mimic important physiological functions of native kidneys in recipients to support their native kidney function. The product is designed to replace the need for external kidney dialysis, without the need for immunosuppression.

Ex Vivo Lung Perfusion

Our ex vivo lung perfusion (EVLP) program uses the first FDA-approved acellular EVLP technology on the market, the XVIVO Perfusion System (XPSTM) with Steen SolutionTM Perfusate, to offer the only commercially-available centralized EVLP service in the United States. EVLP technology increases the number of transplantable lungs by giving surgeons the ability to assess the function of marginal lungs to determine if the lungs are suitable for transplantation. This allows for the transplantation of lungs that would have otherwise not been transplanted. Centralized EVLP services make EVLP available to small and large transplant centers and remove barriers to the transplantation process to optimize organ utilization and increase the supply of transplantable lungs.

Our wholly-owned subsidiary, Lung Bioengineering Inc., provides commercial EVLP services on a fee-for-service basis to transplant centers through dedicated facilities located in Silver Spring, Maryland and Jacksonville, Florida, using the XPS System. Lung Bioengineering has also recently completed a registrational study of another centralized EVLP technology called the Centralized Lung Evaluation System (CLES) and plans to submit a PMA to the FDA during 2024 for commercial approval of CLES.

As of the end of 2023, approximately 380 patients have received lung transplants following use of our centralized EVLP service.

Sustainable Delivery of Organs

Together with therapeutic interventions, we are developing scalable technologies to efficiently deliver an unlimited supply of manufactured organs to transplant centers and waiting patients, while minimizing environmental impact. Our drone delivery research efforts are focused on the development of piloted and autonomous electric vertical take-off and landing (eVTOL) aircraft systems to quickly, reliably, and sustainably deliver organs for transplant from manufacturing facilities to transplant centers.

In October 2021, we successfully completed the first-ever drone delivery of a lung for transplant at Toronto General Hospital, demonstrating the feasibility of our goal of delivering our manufactured organs with zero carbon footprint aircraft.

Aurora-GT

Our affiliate, Northern Therapeutics, Inc. (Northern Therapeutics), is conducting a clinical study in Canada (called SAPPHIRE) of a gene therapy product called Aurora-GT, in which a PAH patient’s own endothelial progenitor cells are isolated, transfected with the gene for human endothelial nitric oxide synthase, expanded ex vivo, and then delivered back to the same patient. This therapy is intended to rebuild the blood vessels in the lungs that are compromised by PAH. Northern Therapeutics is a Canadian entity in which we have a 49.7 percent voting stake and a 71.8 percent financial stake. Northern

Therapeutics discontinued enrollment of new patients at the end of 2022 when we ceased funding the SAPPHIRE program. After reviewing the data from the SAPPHIRE study, which enrolled 12 patients and is expected to unblind in the first half of 2024, we will decide whether to pursue a BLA for Aurora-GT, and Northern Therapeutics will consider whether to initiate further studies. We have the exclusive right to pursue this technology in the United States. Under our agreement with Northern Therapeutics, we funded all of the expenses of the SAPPHIRE program through the end of 2022; thereafter, Northern Therapeutics is solely responsible for all future costs of developing Aurora-GT outside the United States.

RemoPro

During the second quarter of 2023, we terminated the RemoPro program, which was focused on developing a prodrug form of Remodulin.

Sales and Marketing

Our marketing strategy for our commercial PAH and PH-ILD products is to use our sales and marketing teams to reach out to the prescriber community to: (1) increase PAH and PH-ILD awareness; (2) increase understanding of the progressive nature of PAH and the importance of early treatment; (3) communicate the increased risks when ILD patients develop PH-ILD; and (4) increase awareness of our commercial products and how they fit into the various stages of disease progression and treatment.

Distribution of Commercial Products

United States Distribution of Tyvaso DPI, Nebulized Tyvaso, Remodulin, Remunity Pump, Orenitram, and Unituxin

We distribute Tyvaso DPI, nebulized Tyvaso, Remodulin, the Remunity Pump, and Orenitram throughout the United States through two contracted specialty pharmaceutical distributors: Accredo Health Group, Inc. and its affiliates (Accredo) and Caremark, L.L.C. (CVS Specialty). These distributors are required to maintain certain minimum inventory levels in order to ensure an uninterrupted supply to patients who are prescribed our therapies. We compensate Accredo and CVS Specialty on a fee-for-service basis for certain ancillary services in connection with the distribution of these products. If any of our distribution agreements expire or terminate, we may, under certain circumstances, be required to repurchase any unsold inventory held by our distributors.

These specialty pharmaceutical distributors are responsible for assisting patients with obtaining reimbursement for the cost of our treprostinil-based products and providing other support services. Under our distribution agreements, we sell each of our treprostinil-based products to these distributors at a transfer price that we establish. We have also established patient assistance programs in the United States, which provide our treprostinil-based products to eligible uninsured or under-insured patients at no charge. Accredo and CVS Specialty assist us with the administration of these programs.

We distribute Unituxin throughout the United States through an exclusive distribution agreement with ASD Specialty Healthcare, Inc. (ASD), an affiliate of Cencora, Inc. (formerly known as AmerisourceBergen Corporation). Under this agreement, we sell Unituxin to ASD at a transfer price that we establish, and we pay ASD fees for services provided in connection with the distribution and support of Unituxin.

To the extent we increase the price of any of these products, increases are typically in the single-digit percentages per year.

United States Distribution of Adcirca

Under our manufacturing and supply agreement with Lilly, Lilly manufactures and distributes Adcirca on our behalf through its wholesaler network in the same manner that it distributes its own pharmaceutical products. Under the terms of this agreement, we take title to Adcirca upon completion of its manufacture by Lilly. Adcirca is shipped to customers in accordance with purchase orders received by Lilly. Upon shipment, Lilly sends an invoice and collects the amount due from the customer subject to customary discounts and rebates, if any. Although Lilly provides these services on our behalf, we maintain the risk of loss as it pertains to inventory, product returns, and non-payment of invoices. The manufacturing and supply agreement will continue in effect until the December 31, 2026 expiration or earlier termination of our license agreement for Adcirca. Lilly retains authority under the license agreement for all regulatory activities with respect to Adcirca as well as its retail pricing. We have also established a patient assistance program in the United States, which provides Adcirca to eligible uninsured or under-insured patients at no charge.

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International Distribution of Tyvaso DPI, Nebulized Tyvaso, Remodulin, Orenitram, and Unituxin

We currently sell Remodulin outside the United States to various distributors, each of which has exclusive distribution rights in one or more countries within Europe, the Middle East, Asia, and South and Central America. Our primary distributor outside the United States is Grupo Ferrer Internacional, S.A. (Ferrer), which holds Remodulin marketing authorization rights in many of these territories. We sell nebulized Tyvaso commercially to distributors that have exclusive distribution rights in Argentina and Israel. We also sell nebulized Tyvaso exclusively through Mochida in Japan, where the product was approved in late 2022. We also distribute Remodulin and Unituxin in Canada through a specialty pharmaceutical wholesaler. In some of the markets where we are not licensed to market Remodulin, Remodulin is available, but not marketed, on a named patient basis in which therapies are approved for individual patients by a national medical review board, hospital, or health plan on a case-by-case basis. Similar named-patient programs are also available for nebulized Tyvaso in certain countries. We entered into exclusive agreements with Ferrer to distribute Orenitram and nebulized Tyvaso throughout the territories where it also has distribution rights for Remodulin. Initial feedback from the EMA has indicated that approval of either Orenitram or nebulized Tyvaso would require another large clinical trial of the applicable product. As such, the likelihood of commercially launching these products in the European Economic Area is remote. In December 2023, the U.K. Medicines and Healthcare products Regulatory Authority (MHRA) provided positive feedback to Ferrer indicating that the INCREASE study and data from its open label extension could support a marketing authorisation application (MAA) for nebulized Tyvaso to treat PH-ILD without further clinical studies. As a result, Ferrer plans to submit an MAA to the MHRA in mid-2024. We distribute Unituxin in Japan exclusively through Ohara, which obtained Japanese marketing authorization during the second quarter of 2021.

Patents and Other Proprietary Rights, Strategic Licenses, and Market Exclusivity

Our success depends in part on our ability to obtain and maintain patent protection for our products, preserve trade secrets, prevent third parties from infringing upon our proprietary rights, and operate without infringing upon the proprietary rights of others in the United States and worldwide. Many of these proprietary rights stem from licenses and other strategic relationships with third parties. In addition to intellectual property rights, U.S. and international regulatory authorities often provide periods of market exclusivity for manufacturers of biopharmaceutical products.

Patents provide the owner with a right to exclude others from practicing an invention. Patents may cover the active ingredients, uses, formulations, doses, administrations, delivery mechanisms, manufacturing processes, and other aspects of a product. The period of patent protection for any given product generally depends on the expiration date of various patents and may differ from country to country according to the type of patents, the scope of coverage, and the remedies for infringement available in a country. Most of our commercial products and investigational products are protected by patents that expire on varying dates.

Significant legal questions exist concerning the extent and scope of patent protection for biopharmaceutical products and processes in the United States and elsewhere. Accordingly, there is no certainty that patent applications owned or licensed by us will be issued as patents, or that our issued patents will afford meaningful protection against competitors. Once issued, patents are subject to challenge through both administrative and judicial proceedings in the United States and other countries. Such proceedings include re-examinations, inter partes reviews (IPR), post-grant reviews, and interference proceedings before the U.S. Patent and Trademark Office, as well as opposition proceedings before the European Patent Office. Litigation may be required to enforce, defend, or obtain our patent and other intellectual property rights. Any administrative proceeding or litigation could require a significant commitment of our resources and, depending on outcome, could adversely affect the scope, validity, or enforceability of certain of our patent or other proprietary rights.

Tyvaso DPI, Nebulized Tyvaso, Remodulin, and Orenitram Proprietary Rights

We have a number of issued patents and pending patent applications covering our treprostinil-based products, Tyvaso DPI, nebulized Tyvaso, Remodulin, and Orenitram. We have three unexpired patents related to the manufacture of treprostinil that expire in 2028 and are listed in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly known as the Orange Book (see Orange Book below), for Tyvaso DPI, nebulized Tyvaso, Remodulin, and Orenitram. One of these patents is subject to the IPR proceedings discussed below under Generic Competition and Challenges to our Intellectual Property Rights.

In addition to the treprostinil patents noted above, we have other patents specific to our individual treprostinil-based products, including the following:

•Tyvaso DPI. We have three Orange Book-listed U.S. patents that we license from MannKind directed to the composition of Tyvaso DPI drug product, which expire in 2025, 2030, and 2035, respectively. We have another two issued U.S. patents listed in the Orange Book directed to a method of treating pulmonary hypertension (expiring in 2027) and a method of improving exercise capacity in patients with PH-ILD (expiring in 2042). Additionally, our license agreement

with MannKind includes rights to a substantial portfolio of additional issued U.S. patents related to a component of the drug product and methods of making the drug product, which expire at various dates through 2035, and pending applications that, if issued, could extend protection to 2042 or beyond.

•Nebulized Tyvaso. We have been granted two U.S. patents directed to a method of treating pulmonary hypertension and a kit for treating pulmonary hypertension. These two patents expire in 2028 and are listed in the Orange Book. We have also been granted two patents on methods of treating pulmonary hypertension by administering treprostinil by inhalation, which expire in 2027. These two patents are also listed in the Orange Book. Additionally, we have been granted a patent directed to a method of improving exercise capacity in PH-ILD patients, which expires in 2042.

•Remodulin. We have been granted three U.S. patents covering an improved diluent for Remodulin, which expire in 2028 and 2029. We have another patent covering intravenous administration of Remodulin with certain diluents, which expires in 2024. We have been granted two patents covering a treprostinil formulation with a citrate buffer, which expire in 2024. We have been granted another patent covering a method of treating pulmonary hypertension by administering treprostinil at a certain rate intravenously, which expires in 2024. All seven of these patents are listed in the Orange Book.

•Orenitram. Our U.S. patents for Orenitram cover methods of use for treating PAH, orally administered formulations, controlled moisture storage and manufacturing methods, as well as those covering controlled release formulations licensed to us by Supernus Pharmaceuticals Inc. (Supernus). These patents will expire in the United States between 2024 and 2031.

We have international counterparts to many of the patents discussed above and additional pending U.S. and international patent applications related to Tyvaso DPI, nebulized Tyvaso, Remodulin, and Orenitram.

Orange Book

In seeking approval of a drug through an NDA or upon issuance of new patents following approval of an NDA, applicants are required to submit to the FDA each patent that has claims covering the applicant’s product or a method of using the product. Each of the patents submitted is then published in the Orange Book. See Governmental Regulation—Patent Term and Regulatory Exclusivity below for further details. Tyvaso DPI currently has eight unexpired Orange Book-listed patents with expiration dates ranging from 2025 to 2042. Nebulized Tyvaso currently has eight unexpired Orange Book-listed patents expiring at various dates from 2027 to 2042. Remodulin currently has ten unexpired Orange Book-listed patents with expiration dates ranging from 2024 to 2029. Orenitram currently has twelve unexpired Orange Book listed patents with expiration dates ranging from 2024 to 2031. Additional patent applications are pending, and if granted, may be eligible for listing in the Orange Book.

Regulatory Exclusivity

•Tyvaso DPI and Nebulized Tyvaso.In 2010, the FDA granted orphan drug designation for Tyvaso, which resulted in an orphan exclusivity period that expired in July 2016. In March 2021, the FDA granted Tyvaso three-year clinical trial exclusivity for PH-ILD as a result of the INCREASE study and the expansion of the Tyvaso label to include a PH-ILD indication. This exclusivity period will extend through March 2024, and also covers Tyvaso DPI for PH-ILD. In 2004, the European Commission designated Tyvaso an orphan medicinal product for the treatment of both PAH and chronic thromboembolic pulmonary hypertension, which would confer a ten-year exclusivity period commencing if and when we obtain marketing approval. In December 2020, the FDA granted orphan designation for treprostinil for the treatment of IPF. Thus, if we obtain FDA approval to update the Tyvaso DPI and/or nebulized Tyvaso labeling to include an IPF indication, then the FDA should grant seven-year orphan drug exclusivity for this new indication. The EMA has also granted orphan drug designation for treprostinil to treat IPF.

•Remodulin.Regulatory exclusivity for Remodulin in the United States and Europe has expired.

•Orenitram.In November 2019, following approval of our supplemental NDA to reflect the FREEDOM-EV results in the Orenitram label, the FDA granted orphan exclusivity for the new indication that Orenitram delays disease progression in PAH patients. This exclusivity expires in October 2026.

Supernus License

In 2006, we entered into an exclusive license agreement with Supernus to use certain of its technologies in manufacturing Orenitram. Under the agreement, we paid Supernus certain amounts upon the achievement of specified milestones based on the development and commercial launch of Orenitram for PAH, and we would be obligated to make additional milestone payments if we develop Orenitram for a second indication. In addition, the agreement provides that we will pay a single-digit percentage royalty based on net worldwide sales. The term of this royalty expires during the fourth quarter of 2026.

Manufactured Organ Proprietary Rights

We have a large portfolio of pending patent applications and issued patents that could protect our proprietary rights in our manufactured organ products. We own patents, and have licensed rights under third-party patents, covering various aspects of our organ manufacturing programs; we do not view any one patent or particular group of patents as critical to our organ

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manufacturing programs. For example, we have over 50 pending patent applications and one issued U.S. patent covering various aspects of our 3-D organ bioprinting program, and we have exclusively licensed an extensive 3-D printing patent portfolio from 3D Systems for use in the field of solid organ manufacturing. Our xenotransplantation patent portfolio includes over 150 pending applications and issued patents, including nearly one hundred issued patents in the U.S. and abroad. Our regenerative medicine patent portfolio, including our newly-acquired Miromatrix and IVIVA programs, includes over 300 pending applications and issued patents.

Our patent portfolio covers various aspects of our organ manufacturing programs, including genetic constructs, manufacturing methods, end products, and components used in the manufacture of organs. The applicability of our patent portfolio to our programs will depend on the final commercial organ manufacturing products we provide and processes we use and the timing of regulatory approvals. In addition, we may rely on trade secret protection for certain aspects of our organ manufacturing programs.

Generic Competition and Challenges to our Intellectual Property Rights

Remodulin—Generic Competition

We settled litigation with Sandoz, Inc. (Sandoz) related to its ANDA seeking FDA approval to market a generic version of Remodulin and in March 2019, Sandoz announced the availability of its generic product in the United States. We have also entered into similar settlement agreements with other generic companies, some of which have also launched sales of generic versions of Remodulin. Through December 31, 2023, we have seen limited erosion of Remodulin sales as a result of the availability of generic treprostinil injection in the United States. We are currently engaged in litigation with Sandoz and its marketing partner, RareGen (now a subsidiary of Liquidia Corporation, the parent company of Liquidia Technologies, Inc. (Liquidia)), related to the infusion devices used to administer Remodulin subcutaneously. We understand that generic treprostinil was initially launched by Sandoz/RareGen for use only by intravenous infusion. In May 2021, Sandoz/Liquidia Corporation announced that Sandoz’s generic treprostinil was made available for subcutaneous use, following FDA clearance of a cartridge that can administer the product via the Smiths Medical CADD MS-3 pump. See Note 14—Litigation, to our consolidated financial statements included in this Report.

Regulatory authorities in various European countries began approving generic versions of Remodulin in 2018, followed by pricing approvals and commercial launches in most of these countries in 2019 and 2020. As a result, our international Remodulin revenues have decreased compared to the period prior to generic launch, due to increased competition and a reduction in our contractual transfer price for Remodulin sold by certain international distributors for sales in countries in which the pricing of Remodulin is impacted by the generic competition.

Nebulized Tyvaso and Orenitram—Potential Future Generic Competition

We settled litigation with Watson and Actavis related to their ANDAs seeking FDA approval to market generic versions of nebulized Tyvaso and Orenitram, respectively, before the expiration of certain of our U.S. patents. Under the settlement agreements, Watson and Actavis can market their generic versions of nebulized Tyvaso and Orenitram in the United States beginning in January 2026 and June 2027, respectively, although they may be permitted to enter the market earlier under certain circumstances. In May 2022, we settled litigation with ANI regarding its ANDA seeking FDA approval to market a generic version of Orenitram. Under the settlement agreement, ANI can market its generic version of Orenitram in the United States beginning in December 2027, although it may be permitted to enter the market earlier under certain circumstances. Competition from these generic companies could reduce our net product sales and profits. See Note 14—Litigation, to our consolidated financial statements included in this Report.

Liquidia—Yutrepia

We are engaged in patent litigation with Liquidia concerning four patents related to Tyvaso DPI and nebulized Tyvaso. The litigation is proceeding in parallel in two fora: (1) federal court; and (2) the Patent Trial and Appeal Board (PTAB) of the U.S. Patent and Trademark Office (USPTO).

In January 2020 Liquidia submitted an NDA to the FDA for approval of YutrepiaTM, a dry powder formulation of treprostinil for inhalation, to treat PAH. The Yutrepia NDA was submitted under the 505(b)(2) regulatory pathway with nebulized Tyvaso as the reference listed drug and received tentative approval from the FDA in November 2021. If and when Liquidia launches commercial sales of Yutrepia, it would compete directly with Tyvaso DPI, nebulized Tyvaso, and our other treprostinil-based products.

Following the initial submission of the Yutrepia NDA, we filed a lawsuit in federal district court against Liquidia for infringement of three of our patents: U.S. Patent Nos. 9,604,901 (the ’901 patent), 9,593,066 (the ’066 patent), and 10,716,793 (the ’793 patent). In December 2021, we filed a stipulation that the ’901 patent would not be infringed by Liquidia based on the court’s claim construction ruling. In August 2022, the court found that Liquidia’s product would infringe the ’793 patent and that Liquidia had not proved that any claim of that patent is invalid. The court also determined that Liquidia had proved that certain claims of the ’066 patent were invalid and that we had not proved Liquidia’s infringement of another ’066 patent claim. Accordingly, the court issued a final judgment that bars the FDA from approving Liquidia’s approved product until expiration of the ’793 patent in May 2027. The parties each appealed portions of the decision adverse to them, and in July 2023, the appellate court issued its decision affirming the district court decision in its entirety. The court subsequently

denied the parties’ requests for rehearing, and the appellate court decision is now final. On January 23, 2024, Liquidia filed a petition for writ of certiorari with the U.S. Supreme Court seeking review of the appellate decision. That petition was denied on February 20, 2024.

Separately, Liquidia has been attempting to invalidate these patents by filing petitions for IPR with the PTAB. Challengers in IPR proceedings have a lower burden of proof (preponderance of the evidence) relative to district court litigation (clear and convincing evidence) to successfully challenge the validity of patent claims.

•’066 patent: In October 2020, the PTAB declined to institute IPR proceedings relating to this patent because Liquidia failed to establish a reasonable likelihood of prevailing on any claim of this patent.

•’901 patent: In October 2021, the PTAB issued a final written decision on Liquidia’s IPR relating to this patent. The PTAB upheld the patentability of two of the claims of this patent, one of which was being asserted against Liquidia in the district court litigation, and found that seven other claims of this patent were unpatentable. We have appealed the PTAB’s decision, and the appeal is pending. All claims of this patent remain valid until any IPR appeals are exhausted. In December 2021, we filed a stipulation in the district court litigation that the ’901 patent would not be infringed by Liquidia based on the court’s claim construction ruling.

•’793 patent: In August 2021, the PTAB instituted IPR proceedings related to this patent. In July 2022, the PTAB issued a final written decision finding all claims of this patent to be unpatentable. We appealed this decision, and the appellate court affirmed the PTAB’s decision. On January 19, 2024, we filed a petition for rehearing with the appellate court, and that petition is pending. All claims of this patent remain valid until any IPR appeals are exhausted.

Liquidia could obtain final FDA approval for its proposed product prior to May 2027 in two circumstances: (1) Liquidia could prevail on appeal, either from the district court judgment or IPR proceedings, such that its product is not found to infringe any valid claims of our patents; or (2) the district court could modify the district court order barring FDA approval of its product. Liquidia has filed a motion with the district court to modify the final judgment such that it can obtain final FDA approval immediately, and that motion is fully briefed and pending.

On September 5, 2023, we filed a lawsuit in federal district court against Liquidia for infringement of the ’793 patent based on Liquidia’s efforts to obtain approval from the FDA for a PH-ILD indication for Yutrepia. On November 30, 2023, we filed an amended complaint to assert a new patent: U.S. Patent No. 11,826,327 (the ’327 patent). The claims of the ’327 patent generally cover improving exercise capacity in patients suffering from PH-ILD by inhaling treprostinil at specific dosages. On January 22, 2024, we filed a stipulation withdrawing the ’793 patent from the case. As a result, the ’327 patent is the only patent at issue in the case. Liquidia answered the complaint asserting a variety of defenses. The case is pending, and the court has not yet set a schedule for the case.

The FDA granted nebulized Tyvaso three-year clinical trial exclusivity for the treatment of PH-ILD, expiring in March 2024, as a result of the INCREASE study of nebulized Tyvaso for the treatment of PH-ILD, and the expansion of the nebulized Tyvaso label to include a PH-ILD indication. This exclusivity covers both Tyvaso DPI and nebulized Tyvaso for the treatment of PH-ILD and precludes the FDA from approving a PH-ILD indication for Yutrepia prior to the expiration of clinical trial exclusivity. On July 24, 2023, we received a Paragraph IV Certification Notice Letter from Liquidia notifying us that they had submitted an amendment to the Yutrepia NDA to include a PH-ILD indication to the FDA. In September 2023, Liquidia announced that the FDA had accepted this amendment for review, and set a PDUFA target action date of January 24, 2024. On January 25, 2024, Liquidia announced that the FDA had not yet completed its review of the NDA and did not provide an updated timeline. On January 25, 2024, Liquidia announced that the FDA had not yet completed its review of the NDA and did not provide an updated timeline.

On February 20, 2024, we filed a lawsuit against the FDA in federal district court regarding its review of Liquidia’s PH-ILD amendment. We allege that Liquidia’s amendment to its NDA to add PH-ILD to the Yutrepia labeling was improper under FDA rules, precedents, and procedures, and instead Liquidia should have submitted an entirely new NDA. In our lawsuit, we have requested that FDA require Liquidia to submit a new NDA in lieu of its NDA amendment. In the event a new NDA is submitted, we believe Liquidia will be required to follow the Hatch-Waxman Paragraph IV notification process, and as a result our lawsuit asserting infringement of the ‘327 patent would result in a 30-month stay preventing the FDA from approving the new NDA until the earlier of resolution of the litigation or 30 months following receipt of a Paragraph IV notice from Liquidia.

For further details, see Note 14—Litigation, to our consolidated financial statements.

Adcirca—Generic Competition

A U.S. patent for Adcirca for the treatment of pulmonary hypertension expired in November 2017 and FDA-conferred regulatory exclusivity expired in May 2018, leading to the launch of a generic version of Adcirca by Mylan N.V. in August 2018, and by additional companies in February 2019. Generic competition for Adcirca has had a material adverse impact on Adcirca net product sales.

General

We intend to vigorously enforce our intellectual property rights related to our products. However, we may not prevail in defending our patent rights, and additional challenges from other ANDA filers or other challengers may surface with respect to our products. Our patents could be invalidated, found unenforceable, or found not to cover one or more generic forms of our products. If any ANDA filer or filer of a 505(b)(2) NDA for a branded treprostinil product were to receive approval to sell

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its treprostinil product and/or prevail in any patent litigation, our affected product(s) would become subject to increased competition. Patent expiration, patent litigation, and competition from generic or other branded treprostinil manufacturers could have a significant, adverse impact on our treprostinil-based product revenues (including the anticipated revenues from new products such as Tyvaso DPI), our profits, and our stock price. These potential effects are inherently difficult to predict. For additional discussion, see the risk factor entitled, Our intellectual property rights may not effectively deter competitors from developing competing products that, if successful, could have a material adverse effect on our revenues and profits, contained in Part I, Item 1A—Risk Factors included in this Report.

Adcirca License Agreement

In 2008, Lilly granted us an exclusive license to develop, market, promote, and commercialize Adcirca for the treatment of pulmonary hypertension in the United States. We agreed to pay Lilly royalties based on our net product sales of Adcirca. Lilly retained the exclusive rights to develop, manufacture, and commercialize pharmaceutical products containing tadalafil, the active pharmaceutical ingredient in Adcirca, for the treatment of pulmonary hypertension outside of the United States and for the treatment of other diseases worldwide. Lilly retained authority for all regulatory activities with respect to Adcirca and for setting the wholesale price of Adcirca. In May 2017, we amended our Adcirca license agreement with Lilly in order to clarify and extend the term of the agreement and to amend the economic terms of the agreement following a patent expiry in November 2017. As a result, we are required to make milestone payments to Lilly equal to $325,000 for each $1.0 million in net product sales, plus a royalty equal to ten percent of our net product sales. The current term of our Adcirca license agreement expires December 31, 2026. Following expiration of the agreement, we will remain obligated to refund the purchase price of any Adcirca that we previously sold to distributors that expires unsold. For additional discussion, see our Adcirca product description included in Part I, Item 1—Business Overview—Products to Treat Pulmonary Arterial Hypertension.

We also agreed to purchase Adcirca at a fixed manufacturing cost. The agreement provides a mechanism, generally related to the increase in the national cost of pharmaceutical manufacturing, pursuant to which Lilly may raise the manufacturing cost of Adcirca.

Unituxin Proprietary Rights and Regulatory Exclusivity

Approval of our BLA for Unituxin conferred a 12-year data exclusivity period through March 2027, during which the FDA may not approve a biosimilar for Unituxin. Our orphan drug exclusivity in the United States for Unituxin expired in March 2022. Under a non-exclusive license agreement with The Scripps Research Institute, we pay a royalty of one percent of Unituxin net product sales. We have no patents covering Unituxin.

DEKA Agreements

In December 2014, we entered into an exclusive agreement with DEKA to develop a semi-disposable system for subcutaneous delivery of Remodulin, which we refer to as the Remunity Pump. Our agreement with DEKA expires on the last to occur of 25 years from the first product launch under the agreement, or upon the expiration of the last valid claim of a patent licensed from DEKA under the agreement that covers the Remunity Pump. Under the terms of the agreement, we funded the development costs related to the Remunity Pump, and will continue to fund further development costs associated with new versions of the pump. We pay product fees and a single-digit royalty to DEKA based on commercial sales of the Remunity Pump and the Remodulin drug product sold for use with the system. Either party may terminate the agreement immediately upon a material breach by the other party that is uncured following the relevant cure period, or in the event of the other party’s bankruptcy or insolvency. In November 2019, we entered into a supply agreement with an affiliate of DEKA to manufacture and supply the Remunity Pump. Under this supply agreement, we are responsible for all costs associated with manufacturing the Remunity Pump. The Remunity Pump is covered by issued patents and pending patent applications both in the U.S. and other countries. The expiration dates of currently issued U.S. patents range from 2027 through 2033.

Tyvaso DPI and the MannKind Agreement

In September 2018, we entered into a worldwide, exclusive license and collaboration agreement with MannKind for the development and commercialization of Tyvaso DPI for the treatment of PAH. The agreement became effective on October 15, 2018.

Under our agreement with MannKind, we are responsible for global development, regulatory, and commercial activities related to Tyvaso DPI, and we share manufacturing responsibilities with MannKind. Under the terms of the agreement, we paid MannKind $45.0 million following the effectiveness of the agreement in October 2018, and we paid $25.0 million in each of 2019 and 2020 following the achievement of specific development targets. The agreement also requires us to pay MannKind a ten percent royalty on our net sales of Tyvaso DPI, subject to certain reductions. In addition, we have the option, in our sole discretion, to expand the license to include other active ingredients for the treatment of pulmonary hypertension. We will pay MannKind up to $40.0 million in additional option exercise and development milestone payments

for each product (if any) added to the license pursuant to this option, as well as a low double-digit royalty on our net sales of any such product.

In December 2023, MannKind entered into a royalty purchase agreement with Sagard Healthcare Funding Partners Borrowers 2 SPE, LP, with our consent, to sell ten percent of the royalties payable under the license agreement (i.e., one percentage point of the ten percent royalty) in exchange for $150.0 million up-front, plus up to an additional $50.0 million if net sales of Tyvaso DPI meet certain thresholds. Based on the up-front purchase price alone, the implied net present value of future Tyvaso DPI net revenues is $15.0 billion.

Under our license agreement with MannKind, we have an exclusive license to a variety of granted and pending patents and patent applications related to treprostinil inhalation powder and the Dreamboat device, including multiple patent families covering the U.S. and other major market countries. These patents cover drug formulation, devices and device components, and manufacturing processes and intermediates. For additional detail concerning these patents, see Tyvaso DPI, Nebulized Tyvaso, Remodulin, and Orenitram Proprietary Rights above.

In August 2021 we entered into a commercial supply agreement with MannKind (as amended, the Supply Agreement). Pursuant to the Supply Agreement, MannKind is responsible for manufacturing and supplying Tyvaso DPI to us on a cost-plus basis. Unless earlier terminated, the initial term of the Supply Agreement continues until December 31, 2031 and will thereafter be renewed automatically for additional, successive two-year terms unless we give 24 months’ written notice of non-renewal, or MannKind gives 48 months’ written notice of non-renewal, prior to the end of the initial term or any additional renewal term. In addition, each party has customary termination rights, including termination for the other party’s material breach that is not cured within a specific timeframe or in the event of liquidation, bankruptcy, or insolvency of the other party.

Ralinepag and the Arena Agreement

On November 15, 2018, we entered into an exclusive license agreement with Arena Pharmaceuticals, Inc. (Arena) related to ralinepag. On January 24, 2019, in connection with the closing of the transactions contemplated by the license agreement: (1) Arena granted to us perpetual, irrevocable, and exclusive rights throughout the universe to develop, manufacture, and commercialize ralinepag; (2) Arena transferred to us certain other assets related to ralinepag, including, among others, related domain names and trademarks, permits, certain contracts, inventory, regulatory documentation, Investigational New Drug (IND) Application No. 109021 (related to ralinepag), and non-clinical, preclinical, and clinical trial data; (3) we assumed certain limited liabilities from Arena, including, among others, all obligations arising after the closing under the assumed contracts and the IND described above; and (4) we paid Arena $800.0 million, which we expensed as acquired in-process research and development and included within research and development expenses in our consolidated statements of operations for the year ended December 31, 2019. We will also pay Arena: (1) a one-time payment of $250.0 million for the first, if any, marketing approval we receive in the United States for an inhaled version of ralinepag to treat PAH; (2) a one-time payment of $150.0 million for the first, if any, marketing approval we receive in any of Japan, France, Italy, the United Kingdom, Spain, or Germany for an oral version of ralinepag to treat any indication; and (3) low double-digit, tiered royalties on net sales of any pharmaceutical product containing ralinepag as an active ingredient, subject to certain adjustments for third-party license payments. Under our license agreement with Arena, we have an exclusive license to a variety of granted and pending patents and applications related to ralinepag covering drug formulation, manufacturing, and dosage, among others. Many of these patents and patent applications would be eligible for listing in the Orange Book. In March 2022, Arena was acquired by Pfizer Inc. Based on potential patent term extensions and additional patent filings, we believe that U.S. patent protection for ralinepag will likely last through at least the mid-2030s.

Other

We are party to various other license agreements related to therapies and technologies under development. These license agreements require us to make payments based on a percentage of sales if we are successful in commercially developing these therapies, and may require other payments upon the achievement of certain milestones.

Manufacturing and Supply

We synthesize treprostinil, the active ingredient in Tyvaso DPI, nebulized Tyvaso, and Remodulin, and treprostinil diolamine, the active ingredient in Orenitram, at our facilities in Silver Spring, Maryland. We produce dinutuximab, the active ingredient in Unituxin, at our Silver Spring facility. We manufacture drug product for nebulized Tyvaso, Remodulin, and Unituxin at our Silver Spring facility. We manufacture Orenitram drug product and we package, warehouse, and distribute nebulized Tyvaso, Remodulin, Orenitram, and Unituxin at our facilities in Research Triangle Park, North Carolina.

We maintain, at a minimum, a two-year inventory of nebulized Tyvaso, Remodulin, and Orenitram based on expected demand, and we contract with third-party contract manufacturers to supplement our capacity for some products, in order to mitigate the risk that we might not be able to manufacture internally sufficient quantities to meet patient demand. For example, Simtra BioPharma Solutions (formerly known as Baxter Pharmaceutical Solutions, LLC) is approved by the FDA, the EMA, and various other international regulatory agencies to manufacture Remodulin for us. We rely on Woodstock Sterile

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Solutions to serve as an additional manufacturer of nebulized Tyvaso drug product. We have no plans to develop a redundant manufacturing source for dinutuximab, the active ingredient in Unituxin, or for finished Unituxin or Orenitram drug product.

MannKind warehouses and distributes Tyvaso DPI on our behalf at its Danbury, Connecticut facility. We plan to commence warehousing and distribution of Tyvaso DPI at our Research Triangle Park facilities during the first quarter of 2024, to supplement MannKind’s warehousing and distribution activities. We currently rely entirely on MannKind to manufacture Tyvaso DPI finished drug product and inhalers, and we are constructing a facility in Research Triangle Park to manufacture our own supply of Tyvaso DPI finished drug product.

We rely on Minnetronix Inc. and Phillips-Medisize Corp. to manufacture the nebulizer used in our Tyvaso Inhalation System and various third parties to manufacture the monthly disposable device accessories for the Tyvaso Inhalation System. We rely entirely on Lilly to manufacture Adcirca. We currently rely on third-party contract manufacturers to produce ralinepag.

We rely entirely on third parties to supply pumps and other supplies necessary to administer Remodulin. ICU Medical discontinued manufacturing the MS-3 system used to administer subcutaneous Remodulin, and specialty pharmacy distributors have informed us that supplies of MS-3 pumps are exhausted. ICU Medical has also discontinued manufacturing and distribution of the CADD-Legacy system used to administer intravenous Remodulin. Historically, these were the pumps primarily used to administer Remodulin to patients in the United States. In 2021, we launched the Remunity Pump to administer subcutaneous Remodulin, and in 2022 ICU Medical made an alternative pump, the CADD-Solis, available for intravenous Remodulin. We rely entirely on DEKA and its affiliates to manufacture the Remunity Pump for us. In June 2023, our third-party contract manufacturer, Gilero, obtained FDA clearance for a cartridge to be used with the MS-3 pump for subcutaneous infusion of Remodulin. This clearance will enable us to help ensure continuity of cartridge supplies to existing patients using the MS-3 pump. We are also engaged in further efforts to develop alternative pumps to administer Remodulin.

Although we believe that additional third parties could provide similar products, services, and materials, there are few companies that could replace our existing third-party manufacturers and suppliers. A change in supplier or manufacturer could cause a delay in the manufacturing, distribution, and research efforts associated with our respective products or result in increased costs. See also Item 1A—Risk Factors included in this Report.

Competition

Many drug companies engage in research, development, and commercialization of products to treat cardiopulmonary diseases and cancer. For the treatment of PAH, we compete with many approved products in the United States and the rest of the world. In the U.S., these competitive therapies include oral ERAs (Letairis® (ambrisentan), Opsumit® (macitentan), Tracleer® (bosentan), generic bosentan, and generic ambrisentan); prostacyclin-class therapies (Flolan (intravenous epoprostenol), Uptravi® (oral selexipag), Veletri® (intravenous epoprostenol), Ventavis® (inhaled epoprostenol), generic epoprostenol, and generic treprostinil injection); PDE-5 inhibitors (Revatio® (sildenafil), generic sildenafil, and generic tadalafil); and Adempas® (riociguat), an sGC stimulator that targets a similar vasodilatory pathway as PDE-5 inhibitors. These therapies are manufactured and marketed by large pharmaceutical companies such as Johnson & Johnson, Gilead Sciences, Inc., and Bayer Schering Pharma AG, as well as a variety of large generic drug manufacturers.

There are also a wide variety of investigational PAH therapies in development. Therapies in registration-phase studies, or which have completed registration-phase studies, include the following:

•Yutrepia, a dry powder formulation of treprostinil developed by Liquidia, which is designed for pulmonary delivery using a disposable inhaler. In November 2021, Liquidia announced the FDA granted tentative approval for its NDA for Yutrepia to treat PAH, with final approval pending resolution of the regulatory stay triggered by the litigation described above under Patent and Other Property Rights, Strategic Licenses, and Market Exclusivity—Generic Competition and Challenges to our Intellectual Property Rights. In late 2020, Liquidia completed a business combination with RareGen, LLC, which markets a generic version of Remodulin manufactured by Sandoz. Liquidia has submitted an amendment to the Yutrepia NDA to include a PH-ILD indication. In September 2023, Liquidia announced that the FDA had accepted this amendment for review, and set a PDUFA target action date of January 24, 2024. On January 25, 2024, Liquidia announced that the FDA had not yet completed its review of the NDA and did not provide an updated timeline. The regulatory process concerning Liquidia’s NDA is subject to the litigation described in Note 14—Litigation, to our consolidated financial statements.

•Sotatercept, an injected activin signaling inhibitor being developed by Acceleron Pharma, Inc. (Acceleron), which was acquired by Merck, to treat PAH thorough the TGF-beta signaling pathway. Merck announced positive top-line results of a phase 3, registration trial in PAH called STELLAR in October 2022, and submitted an NDA to the FDA with a PDUFA target action date of March 26, 2024. Acceleron indicated it may also study sotatercept in PH-ILD patients.

•Imatinib, a drug currently used to treat cancer under the trade name Gleevec®, is being developed separately for the treatment of PAH by three companies. Tenax Therapeutics, Inc. announced plans to initiate a phase 3 study of an oral formulation. Aerovate Therapeutics, Inc. is conducting a phase 2/3 clinical study of an inhaled, dry powder formulation of imatinib. Aerami Therapeutics Holdings, Inc. completed a phase 1 trial of an inhaled formulation of imatinib in 2023, and has announced plans for a phase 2 study in PAH and PH-ILD patients.

•MK-5475, an inhaled soluble guanylate cyclase stimulator being developed by Merck for PAH in a phase 2/3 trial and in a phase 2 trial for PH-COPD patients.

•L606, an inhaled, liposomal form of treprostinil being developed by Pharmosa Biopharm Inc. (Pharmosa) for PAH and PH-ILD, which completed a phase 1 study in healthy volunteers. In June 2023, Liquidia announced it had entered into an exclusive licensing agreement for development and commercialization of L606 in North America, and that the product is the subject of a phase 3 clinical trial in patients with PH-ILD, with the intent of obtaining approval for the treatment of both PAH and PH-ILD via the 505(b)(2) regulatory pathway, with nebulized Tyvaso as the reference listed drug.

Additional therapies being studied for PAH include Insmed Incorporated’s TPIP (INS1009, an inhaled version of treprostinil) (phase 2); Keros Therapeutics’ KER-012 (phase 2); Novartis’ LTP001 (phase 2); Gossamer Bio, Inc.’s seralutinib (GB002) (phase 3); SoniVie’s TIVUSTM (pivotal trial); Respira Therapeutics’ vardenafil (RT234) (phase 2b); and Cereno Scientific’s valproic acid (CS1) (phase 2).

Oral non-prostacyclin therapies (such as PDE-5 inhibitors and ERAs) are commonly prescribed as first-line treatments for less severely ill PAH patients. As patients progress in their disease severity, additional advanced approved therapies, such as inhaled prostacyclin analogues (including Tyvaso DPI and nebulized Tyvaso) or infused prostacyclin analogues (including Remodulin) are then commonly added. Orenitram was the first approved oral prostacyclin-class therapy for PAH in the United States, and offers a more convenient alternative therapy to Remodulin, Tyvaso DPI, and nebulized Tyvaso. The use of available oral therapies could delay many patients’ need for inhaled or infused prostacyclin therapy. As a result, the availability of oral therapies affects demand for our inhaled and infused products. In addition, sotatercept presents a potential new way of treating PAH, and if approved, could provide added competition for our treprostinil-based therapies. A majority of patients enrolled in the STELLAR clinical trials of sotatercept were on background prostacyclin-class therapies such as treprostinil. We believe sotatercept may offer a complementary treatment in combination with our treprostinil-based therapies, although some physicians could choose to prescribe sotatercept prior to initiating prostacyclin therapy.

Orenitram faces direct competition from Uptravi, which is indicated to delay disease progression and reduce the risk of hospitalization for PAH. Orenitram’s initial indication was limited to the improvement of exercise capacity, which may have led physicians to prescribe Uptravi instead of Orenitram. However, Uptravi is an oral IP prostacyclin receptor agonist. While prostacyclin analogues such as Orenitram broadly mimic the effect of prostacyclin, IP prostacyclin receptor agonists bind selectively to the IP receptor, one of several prostacyclin receptors. In addition, Orenitram’s label allows physicians flexibility to titrate each patient’s dosing up to a level according to tolerability, without any stated maximum. By contrast, Uptravi’s label specifies a specific maximum dose. Given the progressive nature of PAH, many patients initiate Orenitram or another one of our treprostinil-based therapies after their disease progresses while taking Uptravi. In August 2018, we announced the results of our FREEDOM-EV clinical study, which demonstrated that Orenitram delays time to clinical worsening, demonstrated improvement across key clinical measures, and, at study closure, indicated a positive impact on survival rates. In October 2019, the FDA approved a supplement to our Orenitram NDA expanding the Orenitram label to indicate that it also delays disease progression, in addition to improving exercise capacity. We believe that these clinical results and updated labeling have resulted in increased use of Orenitram.

We have faced generic competition for Adcirca since the launch of generic tadalafil in the United States in August 2018, which has significantly reduced our Adcirca revenues. We have also faced generic competition for Remodulin in the United States and certain European countries since 2019. Finally, we have entered into settlement agreements with Actavis and ANI permitting them to launch generic versions of Orenitram in June 2027 and December 2027, respectively, and with Watson permitting it to launch a generic version of nebulized Tyvaso in January 2026, or in each case earlier under certain circumstances. For details regarding these and other potential generic competitors, see the section above entitled Patents and Other Proprietary Rights, Strategic Licenses, and Market Exclusivity—Generic Competition and Challenges to our Intellectual Property Rights.

Tyvaso DPI, nebulized Tyvaso, and our other treprostinil-based products may face competition from Liquidia if it obtains final FDA approval of Yutrepia, a dry powder inhaled version of treprostinil.

Aside from Tyvaso DPI and nebulized Tyvaso, there are currently no approved therapies to treat PH-ILD. Several PAH drug candidates are also being developed for PH-ILD (e.g., Yutrepia, L606, sotatercept, imatinib, and TPIP). Other companies are now developing, or may in the future develop, other therapies to treat PH-ILD. In addition, the use of antifibrotic therapies to treat underlying lung disease (such as the IPF therapies discussed below) could delay the onset of group 3 pulmonary hypertension.

Following the results of the INCREASE study, we expanded our investigational efforts with inhaled treprostinil to examine its use to treat the lung diseases underlying PH-ILD, including our TETON 1 and TETON 2 studies of nebulized Tyvaso in IPF patients and the TETON PPF study of nebulized Tyvaso in PPF patients. If the TETON program is successful, we anticipate seeking IPF and PPF indications for nebulized Tyvaso and, following completion of any FDA-required bridging studies, Tyvaso DPI. There are currently two therapies that are approved by the FDA to treat IPF: Ofev® (nintedanib), which is marketed by Boehringer Ingelheim International GmbH, and Esbriet® (pirfenidone), which is marketed by F. Hoffman-La Roche Ltd. (Roche). In addition, Ofev is the only therapy approved to treat PPF. However, clinical studies have indicated that these therapies only slow lung function decline in IPF (and in the case of Ofev, PPF) patients, resulting in a significant unmet need for therapies that halt or reverse lung function decline in IPF and PPF. There are a number of potentially competing therapies in advanced clinical development for IPF. These therapies include, but are not limited to: Boehringer Ingelheim’s BI -015550 (phase 3), Bridge Biotherapeutics’ BBT-877(phase 2), Blade Therapeutics’ BLD-0409 (cudeaxestat) (phase 2), CSL Behring’s CSL312 (garadacimab) (phase2), MediciNova, Inc.’s tipelukast (MN-001) (phase 2), Nitto Biopharma’s ND-L02-s0201 (phase

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2), Bristol Myers Squibb Company’s Orencia® (abatacept) (phase 2), BMS-986278 (phase 3), and CC-90001 (phase 2), Endeavor Biosciences’ ENV-101 (phase 2), Pliant Therapeutics’ PLN-74809 (bexotegrast) (Phase 2), Avavlyn Pharma’s AP01 (phase 2), and Horizon Therapeutics plc’s HZN-825 (phase 2). Some or all of these therapies may also be developed as treatments for PPF.

Unituxin may face competition from Qarziba® (dinutuximab beta), an antibody product developed by Apeiron Biologics AG that is approved in Europe to treat high-risk neuroblastoma, but is not approved in the United States. In October 2016, EUSA Pharma (UK) Ltd. (which was acquired by Recordati Group in 2022) announced it had acquired global commercialization rights to Qarziba. In addition, Y-mAbs Therapeutics, Inc. (Y-mAbs), is developing several GD-2 targeting drug candidates, and in November 2020 obtained FDA approval for Danyelza® (naxitamab-gqgk) to treat pediatric and adult patients with relapsed and refractory (second line) high-risk neuroblastoma in bone or bone marrow. Y-mAbs launched commercial sales of Danyelza in 2021. Y-mAbs is also conducting studies of naxitamab for frontline high-risk neuroblastoma.

We compete with the developers, manufacturers, and distributors of all of the products noted above for customers, funding, access to licenses, personnel, third-party collaborators, product development, and commercialization. Some of these companies have substantially greater financial, marketing, sales, distribution and technical resources, and more experience in research and development, product development, manufacturing and marketing, clinical trials, and regulatory matters, than we have.

Governmental Regulation

Pharmaceutical Product Approval Process

The research, development, testing, manufacture, promotion, marketing, distribution, sampling, storage, approval, labeling, record keeping, post-approval monitoring and reporting, and import and export of pharmaceutical products are extensively regulated by governmental agencies in the United States and in other countries. In the United States, failure to comply with requirements under the Federal Food, Drug, and Cosmetic Act (FDC Act), the Public Health Service Act (PHSA), and other federal statutes and regulations, may subject a company to a variety of administrative or judicial sanctions, such as FDA refusal to approve pending NDAs or BLAs, warning letters, product recalls, product seizures, total or partial suspension of manufacturing or distribution, injunctions, fines, civil penalties, and criminal prosecution.

Satisfaction of FDA pre-market approval requirements is extremely costly and typically takes many years. The actual cost and time required may vary substantially based upon the type, complexity, and novelty of the product or disease. Drugs are subject to rigorous regulation and requirements by the FDA in the United States, the EMA in the European Union (EU), and similar regulatory authorities in other countries. The steps ordinarily required before a new drug may be marketed in the United States, which are similar to steps required in most other countries, include: (1) preclinical testing; (2) submission to the FDA of an IND; (3) clinical studies, including well-controlled clinical trials, in healthy volunteers and patients to establish safety, efficacy, and dose-response characteristics for each drug indication; (4) submission of an NDA or BLA to the FDA; and (5) FDA acceptance, review, and approval of the NDA or BLA.

Preclinical Testing

Preclinical tests include laboratory evaluation of product chemistry and formulation, as well as animal studies to explore toxicity and for proof-of-concept. The conduct of the preclinical tests must comply with federal regulations and requirements including good laboratory practices.

Submission of IND

The results of preclinical testing are submitted to the FDA as part of an IND, along with other information including information about product chemistry, manufacturing, and controls, and a proposed clinical trial protocol. Absent FDA objection within 30 days after submission of an IND, the IND becomes effective and the clinical trial proposed in the IND may begin.

Clinical Studies

Clinical trials involve the administration of the investigational new drug to healthy volunteers or patients under the supervision of a qualified investigator. Clinical trials must be conducted: (1) in compliance with federal regulations; (2) in compliance with good clinical practices (GCP), an international standard meant to protect the rights and health of patients and to define the roles of clinical trial sponsors, administrators, and monitors; and (3) under protocols detailing the objectives of the trial, the parameters to be used in monitoring safety and the criteria to be evaluated. Each protocol involving testing on U.S. patients and subsequent protocol amendments must be submitted to the FDA as part of the IND.

The FDA may order the temporary or permanent discontinuation of a clinical trial at any time or impose other sanctions if it believes that the clinical trial is not being conducted in accordance with FDA requirements or presents an unacceptable risk to the clinical trial patients. The study protocol and informed consent information for patients in clinical trials must also be

approved by an institutional review board (IRB). An IRB may also require the clinical trial at a site to be halted temporarily or permanently for failure to comply with the IRB’s requirements, or may impose other conditions.

Clinical trials in support of an NDA typically are conducted in sequential phases, but the phases may overlap.

•Phase 1 involves the initial introduction of the drug into healthy human subjects or patients to assess metabolism, pharmacokinetics, pharmacological actions, side effects associated with increasing doses, and, if possible, early evidence on effectiveness.

•Phase 2 usually involves studies in a limited patient population to assess the efficacy of the drug in specific, targeted indications, explore tolerance and optimal dosage, and identify possible adverse effects and safety risks.

•Phase 3 trials, also called pivotal studies, major studies or advanced clinical trials, demonstrate clinical efficacy and safety in a larger number of patients, typically at geographically diverse clinical study sites, and permit the FDA to evaluate the overall benefit-risk relationship of the drug and provide adequate information for drug labeling.

•Phase 4 studies are often conducted following marketing approval, in order to meet regulatory requirements or to provide additional data related to drug use.

FDA Approval Process

After successful completion of the required clinical testing, an NDA is typically submitted to the FDA in the United States, and a marketing authorization application is typically submitted to the EMA in the EU. FDA approval of the NDA is required before the product may be marketed in the United States. The NDA must include the results of all preclinical, clinical, and other testing and a compilation of data related to the product’s pharmacology, chemistry, manufacture, and controls.

The FDA has 60 days from its receipt of an NDA to determine whether the application will be accepted for filing. If the FDA determines that the application is not sufficiently complete to permit substantive review, it may request additional information and decline to accept the application for filing until the information is provided. Once the submission is accepted for filing, the FDA begins an in-depth review. The FDA has agreed to certain performance goals in the review of NDAs. Most applications for non-priority drugs are reviewed within ten to twelve months. Special expedited pathways, including “accelerated approval,” “fast track” status, “breakthrough therapy” status, and “priority review” status are granted for certain drugs that offer major advances in treatment, or provide a treatment where no adequate therapy exists. These special pathways can significantly reduce the time it takes for the FDA to review an NDA, but do not guarantee that a product will receive FDA approval. In May 2018, the Right to Try Act established a new regulatory pathway to increase access to unapproved, investigational treatments for patients diagnosed with life-threatening diseases or conditions who have exhausted approved treatment options and who are unable to participate in a clinical trial. The Food and Drug Omnibus Reform Act (FDORA), which was passed as part of the Consolidated Appropriations Act, 2023, expands the FDA’s authority in regulating accelerated approval requirements for drugs and biologics, including allowing the FDA to require initiation of a post-approval study before granting accelerated approval and to expedite withdrawal of approval if the conditions for granting accelerated approval are not satisfied.

The FDA may refer applications for novel pharmaceutical products or pharmaceutical products that present difficult questions of safety or efficacy to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation, and a recommendation as to whether the application should be approved. The FDA is not bound by the recommendation of an advisory committee, but it generally follows such recommendations. During the review process, the FDA also reviews the drug’s product labeling to ensure that appropriate information is communicated to health care professionals and consumers. In addition, before approving an NDA, the FDA will typically inspect one or more clinical sites to assure compliance with GCP and the facility or the facilities at which the drug is manufactured to ensure they are in compliance with the FDA’s current Good Manufacturing Practices (cGMP).

After the FDA evaluates the NDA and the manufacturing facilities, the FDA may issue either an approval letter or a complete response letter, which generally outlines the deficiencies in the submission and may require substantial additional testing or information in order for the FDA to reconsider the application. If and when those conditions have been addressed to the FDA’s satisfaction in a resubmission of the NDA, the FDA will issue an approval letter. The FDA has committed to reviewing such resubmissions in two or six months depending on the type of information included. Even after a resubmission, the FDA may decide that the application does not satisfy the regulatory criteria for approval.

Post-Approval Regulatory Requirements

Once an NDA is approved, the product is subject to continuing regulation. For instance, pharmaceutical products may be marketed only for their approved indications and in accordance with the provisions of their approved labeling. The FDA closely regulates the post-approval marketing, labeling, and advertising of prescription drugs, including direct-to-consumer advertising, off-label promotion, industry-sponsored scientific and educational activities, and promotional activities involving the Internet.

Adverse event reporting and submission of periodic reports continue to be required following FDA approval of an NDA. In addition, as a condition of NDA approval, the FDA may require post-marketing testing, including phase 4 clinical studies, and/or a risk evaluation and mitigation strategy (REMS) to help ensure that the benefits of the drug outweigh the potential risks. A REMS can include medication guides, communication plans for healthcare professionals, special training or

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certification for prescribing or dispensing, dispensing only under certain circumstances, special monitoring, and the use of patient registries. Additionally, quality control as well as drug manufacture, packaging, and labeling procedures must continue to conform to cGMP requirements. Manufacturing facilities are subject to continual review and periodic inspections by the FDA and certain state agencies.

Regulatory authorities may withdraw product approvals or request product recalls if a company fails to comply with regulatory standards or if previously unrecognized problems are subsequently discovered. Discovery of previously unknown problems with a product, including adverse events or problems with manufacturing processes of unanticipated severity or frequency, or failure to comply with regulatory requirements, may also result in (1) revisions to the approved labeling; (2) imposition of post-market studies or clinical trials to assess new safety risks; or (3) imposition of distribution or other restrictions under a REMS program. Other potential consequences include: (1) restrictions on the marketing or manufacturing of the product; (2) fines, warning letters, or holds on post-approval clinical trials; (3) refusal of the FDA to approve pending NDAs or supplements to approved NDAs, or suspension or revocation of product license approvals; (4) product seizure or detention, or refusal to permit the import or export of products; or (5) injunctions or the imposition of civil or criminal penalties.

Approval of Changes to an Approved Product

Certain changes to the conditions established in an approved application, including changes in indications, labeling, equipment, or manufacturing processes or facilities, require submission and FDA approval of an NDA or NDA supplement before the change can be implemented. An NDA supplement for a new indication typically requires clinical data similar to that in the original application, and the FDA uses the same procedures and actions in reviewing supplements as it does in reviewing NDAs.

Orphan Drugs

Under the Orphan Drug Act, an applicant can request the FDA to designate a product as an “orphan drug” in the United States if the drug is intended to treat a rare disease or condition affecting fewer than 200,000 people in the United States, or for which there is no reasonable expectation that U.S. sales will be sufficient to recoup the development and production costs. Orphan drug designation must be requested before submitting an NDA or BLA. Orphan drug designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process. The first NDA or BLA applicant to receive orphan drug designation and FDA approval for a particular active ingredient to treat a particular disease via a particular delivery method is entitled to a seven-year exclusive marketing period in the United States. During the seven-year period, the FDA may not approve any other application to market the same drug for the same disease, except in limited circumstances such as a showing of clinical superiority to the product with orphan drug exclusivity, meaning that it has greater effectiveness or safety, or provides a major contribution to patient care (such as a change in delivery system). The FDA’s interpretation of the scope of orphan drug exclusivity remains the subject of scrutiny. Historically, exclusivity was specific to the orphan indication for which the drug was actually approved. As a result, the scope of exclusivity was interpreted as preventing approval of a competing product. However, in September 2021, the federal court in Catalyst Pharmaceuticals, Inc. v. Becerra, suggested that orphan drug exclusivity covers the full scope of the orphan-designated “disease or condition” regardless of whether a drug obtained approval for a narrower use. In January 2023, the FDA clarified in a Federal Register notice that it intends to continue limiting exclusivity to the specific orphan indication. The reach and impact of this decision beyond the Eleventh Circuit is not yet known. Orphan drug exclusivity does not prevent the FDA from approving a different drug for the same disease or condition, or the same drug for a different disease or condition. Orphan drug designation also may qualify an applicant for federal tax credits related to research and development costs.

Patent Term and Regulatory Exclusivity

In 1984, the Hatch-Waxman Act created a faster approval process for generic drugs, called the ANDA. Generally, an ANDA provides for marketing of a drug product that has the same active ingredients in the same strength(s), route of administration, and dosage form as an approved drug and has been shown through bioequivalence testing to be therapeutically equivalent to the approved drug, which is known as the reference listed drug (RLD). ANDA applicants are not required to conduct or submit results of preclinical or clinical tests to prove the safety or effectiveness of their drug product, other than the requirement for bioequivalence testing. Drugs approved in this way are commonly referred to as “generic equivalents” to the approved drug, and can often be substituted by pharmacists under prescriptions written for the original approved drug. In 2018, the FDA advanced policies aimed at promoting drug competition and patient access to generic drugs, such as issuing guidance about making complex generic drugs and the circumstances in which approval of a generic product application may be delayed.

NDA applicants are required to identify each patent with claims that cover the drug (drug substance or drug product) or FDA-approved method of using the drug. Upon product approval, these patents are listed in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly known as the Orange Book. Every ANDA applicant must make one of several certifications to the FDA with regard to each Orange Book listed patent for the RLD. A Paragraph III certification states that the ANDA applicant seeks approval after the patent expires. A Paragraph IV certification asserts that the patent does not block approval of the ANDA, either because the patent is invalid or unenforceable or because the patent, even if valid, is not infringed by the new product. If the applicant does not challenge the listed patents, the ANDA will not be approved until all

the listed patents claiming the referenced product have expired. Alternatively, for a method of use patent covering an approved indication, an ANDA applicant may submit a statement to the FDA that the company is not seeking approval for the covered indication. As a practical matter, this is available only if the RLD is approved for multiple indications, at least one of which is not patent protected.

If the ANDA applicant has submitted a Paragraph IV certification to the FDA, the applicant must also send notice of the Paragraph IV certification to the NDA and patent holders once the ANDA has been accepted for filing by the FDA. The NDA and patent holders may then initiate a patent infringement lawsuit in response to the notice of the Paragraph IV certification. The filing of a patent infringement lawsuit within 45 days of the receipt of a Paragraph IV certification automatically prevents the FDA from approving the ANDA until the earlier of 30 months, expiration of the patent, settlement of the lawsuit, or a decision in the infringement case that is favorable to the ANDA applicant.

The Hatch-Waxman Act also provides that patent terms may be extended to compensate for some of the patent life that is lost during the FDA regulatory review period for a product. This extension period is generally one-half of the time between the effective date of an IND and the submission date of an NDA, plus all of the time between the submission date of an NDA and its approval, subject to a maximum extension of five years, and the limitation that the patent term cannot be extended more than 14 years after approval. Generally, patent term extension is available if the product represents the first permitted commercial marketing of a drug containing the active ingredient. Similar patent term extensions are available under European laws.

An ANDA also will not be approved until any non-patent exclusivity, such as exclusivity for obtaining approval of an NDA for a new chemical entity, has expired. Federal law provides a period of five years following approval of a drug containing no previously approved active ingredient, during which ANDAs for generic versions of those drugs cannot be submitted unless the submission contains a Paragraph IV certification, in which case the submission may be made four years following the original product approval. Following approval of an application to market a drug that contains previously approved active ingredients in a new dosage form, route of administration or combination, or for a new condition of use that was required to be supported by new clinical trials conducted by or for the sponsor, the FDC Act provides three years of exclusivity during which the FDA cannot grant effective approval of an ANDA for such new condition of use, dosage form, or strength that meets certain statutory requirements.

Section 505(b)(2) New Drug Applications

Most drug products (other than biological products) obtain FDA marketing approval pursuant to an NDA submitted under Section 505(b)(1) of the FDC Act, or an ANDA. A third alternative is a special type of NDA submitted under Section 505(b)(2) of the FDC Act, commonly referred to as a Section 505(b)(2) NDA, which enables the applicant to rely, in part, on the FDA’s finding of safety and efficacy data for an existing product, or published literature, in support of its application.

Section 505(b)(2) NDAs may provide an alternate path to FDA approval for new or improved formulations or new uses of previously approved products. Section 505(b)(2) permits the filing of an NDA in which the applicant relies, at least in part, on information from studies made to show whether a drug is safe or effective that were not conducted by or for the applicant and for which the applicant has not obtained a right of reference or use. A Section 505(b)(2) applicant may eliminate the need to conduct certain preclinical or clinical studies, if it can establish that reliance on studies conducted for a previously-approved product is scientifically appropriate. The FDA may also require companies to perform additional studies or measurements to support the change from the approved product. The FDA may then approve the new product candidate for all or some of the labeled indications for which the referenced product has been approved, as well as for any new indication for which the Section 505(b)(2) NDA applicant has submitted data.

To the extent that the Section 505(b)(2) applicant relies on prior FDA findings of safety and efficacy, the applicant is required to certify to the FDA concerning any patents listed for the previously approved product in the Orange Book to the same extent that an ANDA applicant would. Thus, approval of a Section 505(b)(2) NDA can be delayed until all the listed patents claiming the referenced product have expired, until any non-patent exclusivity, such as exclusivity for obtaining approval of a new active ingredient, listed in the Orange Book for the referenced product has expired, and, in the case of a Paragraph IV certification and subsequent patent infringement suit, until the earlier of 30 months, settlement of the lawsuit or a decision in the infringement case that is favorable to the Section 505(b)(2) applicant.

Marketing Pharmaceutical Products Outside the United States

Outside of the United States, our ability to market our products is also contingent upon receiving marketing authorizations from regulatory authorities. The foreign regulatory approval process may include some or all of the risks associated with the FDA review and approval process set forth above, and the requirements governing the conduct of clinical trials and marketing authorization may vary widely from country to country.

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Biologics

Biological products used for the prevention, treatment, or cure of a disease, or condition, of a human being are subject to regulation under the FDC Act and the PHSA. Biological products are approved for marketing via a BLA that follows an application process and carries approval requirements that are very similar to those for NDAs. To help reduce the increased risk of the introduction of adventitious agents, the PHSA emphasizes the importance of manufacturing control for products whose attributes cannot be precisely defined. The PHSA also provides authority to the FDA to immediately suspend licenses in situations where there is a danger to public health, to prepare or procure products in the event of shortages and critical public health needs, and to authorize the creation and enforcement of regulations to prevent the introduction, or spread, of communicable diseases in the United States.

After a BLA is approved, the product may also be subject to official lot release, meaning the manufacturer must submit samples of each lot of product to the FDA together with a release protocol showing a summary of the history of manufacture of the lot and the results of all of the manufacturer’s tests performed on the lot. The FDA may also perform certain confirmatory tests on lots of some products, such as viral vaccines, before releasing the lots for distribution by the manufacturer. As with small-molecule drugs, after approval of biologics, manufacturers must address any safety issues that arise, are subject to recalls or a halt in manufacturing, and are subject to periodic inspection after approval.

The Biologics Price Competition and Innovation Act of 2009 (BPCI Act) created an abbreviated approval pathway for biological products shown to be “biosimilar” to an FDA-licensed reference biological product to minimize duplicative testing. Biosimilarity requires the absence of clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency, which, absent a waiver, must be shown through analytical studies, animal studies, and at least one clinical study. Intricacies associated with the larger, and often more complex, structures of biological products, as well as the processes by which such products are manufactured, pose significant hurdles to implementation that are still being addressed by the FDA. In July 2018, the FDA announced an action plan to encourage the development and efficient review of biosimilars, including the establishment of a new office within the agency that will focus on therapeutic biologics and biosimilars. On December 20, 2020, Congress amended the Public Health Services Act as part of the COVID-19 relief bill to further simplify the biosimilar review process by making it optional to show that conditions of use proposed in labelling have been previously approved for the reference product, which used to be a requirement of the application. In September 2021, the FDA issued two guidance documents, one final and one draft, intended to inform prospective applicants and facilitate the development of proposed biosimilars and interchangeable biosimilars, as well as to describe the FDA’s interpretation of certain statutory requirements added by the BPCIA. In September 2023, the FDA issued additional draft guidance on the same topic.

A reference biologic is granted 12 years of exclusivity from the time of first licensure of the reference product. The first biologic product submitted under the abbreviated approval pathway that is approved as a biosimilar and also meets additional standards for interchangeability with the reference product, has exclusivity against other biologics submitted under the abbreviated approval pathway for a set period. Effective March 2020, certain products that were approved as drugs under the FDC Act, such as insulin and human growth hormone, are now deemed to be biologics under the PHSA, which means they may face competition through the biosimilars pathway and they may not be eligible for the twelve-year period of exclusivity granted to new BLAs. Because biologically sourced raw materials are subject to unique contamination risks, their use may be restricted in some countries. FDORA now provides for multiple first interchangeable biosimilars to qualify for exclusivity if they are approved on the same day.

Cell-Based and Tissue-Based Products

Manufacturers of cell- and tissue-based products must comply with the FDA’s current good tissue practices (cGTP), which are FDA regulations that govern the methods used in, and the facilities and controls used for, the manufacture of such products. The primary intent of the cGTP requirements is to ensure that cell- and tissue-based products are manufactured in a manner designed to prevent the introduction, transmission, and spread of communicable diseases. Cell and tissue-based products may also be subject to the same approval standards, including demonstration of safety and efficacy, as other biologic and drug products, if they meet certain criteria such as if the cells or tissues are more than minimally manipulated or if they are intended for a non-homologous use (a use different from the cell’s origin).

The 21st Century Cures Act established a new FDA Office of Tissues and Advanced Therapies and Regenerative Medicine Advanced Therapy (RMAT) designation, which makes a product eligible for FDA priority review and accelerated approval. Therapies that are eligible for RMAT designation include cell therapies, therapeutic tissue engineering products, human cell and tissue products, or any combination product using these therapies, with certain exceptions. For RMAT designation, the product also must be intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition, and the preliminary clinical evidence must indicate that the product has the potential to address unmet medical needs for the disease or condition.

Regulation of Medical Devices

We currently do not hold any stand-alone medical device authorizations, but we do hold FDA authorization for the Dreamboat inhaler and the Tyvaso Inhalation System as part of the drug-device combination NDAs for Tyvaso DPI and nebulized Tyvaso, respectively. In addition, our business partners have the medical device clearances required to deliver our drugs, including, for example, the Remunity Pump. Medical devices may also be subject to FDA approval and extensive regulation under the FDC Act. Medical devices are classified into one of three classes: Class I, Class II, or Class III. A higher class indicates a greater degree of risk associated with the device and a greater amount of control needed to ensure safety and effectiveness.

All devices, unless exempt by FDA regulation, must adhere to a set of general controls, including compliance with the applicable portions of the FDA’s Quality System Regulation (QSR), which sets forth good manufacturing practice requirements; facility registration and product listing; reporting of adverse medical events; truthful and non-misleading labeling; and promotion of the device consistent with its cleared or approved intended uses. Class II and III devices are subject to additional special controls and may require FDA clearance of a premarket notification (510(k)) or approval of a premarket approval application (PMA).

Most Class I devices are exempt from FDA premarket review or approval. Class II devices, with some exceptions, must be “cleared” by the FDA through the 510(k) process, which requires a company to show that the device is “substantially equivalent” to certain “predicate” devices already on the market. To be substantially equivalent, the proposed device must have the same intended use as the predicate device, and either have the same technological characteristics as the predicate device or have different technological characteristics and not raise different questions of safety or effectiveness than the predicate device. Once a 510(k) is cleared, any change that could significantly affect the safety or effectiveness of the device requires the submission and clearance of a new 510(k) before the change can be implemented. In November 2018, the FDA announced plans to significantly revise the 510(k) program to encourage reliance on modern predicates (e.g., predicates that are less than 10 years old). In January 2019, the FDA also finalized guidance on the alternative 510(k) pathway for well-known device types, the “Safety and Performance Based Pathway,” which relies on modern performance-based criteria and current technological principles to demonstrate substantial equivalence.

Devices deemed by the FDA to pose the greatest risks, such as life-sustaining, life-supporting, or some implantable devices, or devices that have a new intended use, or use advanced technology that is not substantially equivalent to that of a legally-marketed device, are placed in Class III, requiring approval of a PMA application. A PMA generally requires data from clinical trials that establish the safety and effectiveness of the device. Once approved, certain changes, such as changes to manufacturing facilities, methods, or quality control procedures, or changes in the design specifications, which affect the safety or effectiveness of the device, require the submission of a PMA Supplement. Some “pre-amendment” devices (devices that were legally marketed prior to May 28, 1976) are unclassified, but are subject to the FDA’s premarket notification and clearance process in order to be commercially distributed. A 510(k) application also sometimes requires clinical data.

The FDA also allows the submission of a direct de novo petition. This procedure allows a manufacturer whose novel device is automatically classified into Class III to request down-classification of its medical device into Class I or Class II on the basis that the device presents low or moderate risk, rather than requiring the submission and approval of a PMA. Prior to the enactment of the Food and Drug Administration Safety and Innovation Act of 2012 (FDASIA), a medical device could only be eligible for de novo classification if the manufacturer first submitted a 510(k) premarket notification and received a determination from the FDA that the device was not substantially equivalent. FDASIA streamlined the de novo classification pathway by permitting manufacturers to request de novo classification directly without first submitting a 510(k) premarket notification to the FDA and receiving a not substantially equivalent determination.

The 510(k), de novo, and PMA processes can be expensive, lengthy, and unpredictable. The FDA’s 510(k) clearance process usually takes from three to 12 months, but can last longer. The process of obtaining a PMA approval is much more costly and uncertain than the 510(k) clearance process and generally takes from one to three years, or even longer, from the time the application is filed with the FDA. In addition, a PMA approval generally requires the performance of one or more clinical trials. Despite the time, effort, and cost invested by a sponsor, a device may not be approved or cleared by the FDA. The 21st Century Cures Act requires the FDA to establish a program that would expedite access to devices that provide more effective treatment or diagnosis of life-threatening or irreversibly debilitating diseases or conditions, for which no approved or cleared treatment exists or which offer significant advantages over existing approved or cleared alternatives. In December 2018, the FDA published final guidance on this “breakthrough” devices pathway which allows for sponsors to interact directly with the FDA during the development process and to receive prioritized review of their submission. In January 2021, the FDA released final guidance on the Safer Technologies Program (STeP), to encourage the innovation and market entry of device technologies that are safer than current alternatives but that do not otherwise satisfy the breakthrough device criteria, including device technologies to treat non-life-threatening or reasonably reversible conditions. STeP is modeled after the breakthrough device program and is intended to provide similar benefits, including increased communication with the FDA and prioritized review. In September 2023, the FDA updated its guidance entitled “Breakthrough Devices Program Guidance.” The guidance clarifies how the Breakthrough Device Program may apply to certain medical devices that provide more effective treatment or diagnosis methods for life-threatening or irreversibly debilitating diseases or conditions in groups with health or health care disparities.

Clinical trials for medical devices are subject to similar requirements as clinical trials with respect to drugs or biologics. Clinical trials involving significant risk devices (e.g., devices that present a potential for serious risk to the health, safety, or

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welfare of human subjects) are required to obtain both FDA approval of an investigational device exemption (IDE) application and IRB approval before study initiation. Clinical trials involving non-significant risk devices are not required to submit an IDE for FDA approval but must obtain IRB approval before study initiation. During a study, the sponsor is required to comply with the applicable FDA requirements, including, for example, trial monitoring, selecting clinical investigators and providing them with the investigational plan, ensuring IRB review, adverse event reporting, record keeping requirements, and prohibitions on the promotion of investigational devices or on making safety or effectiveness claims about them. The clinical investigators in the clinical study are also subject to FDA regulations and must obtain patient informed consent, rigorously follow the investigational plan and study protocol, control the disposition of the investigational device, and comply with all reporting and recordkeeping requirements. Additionally, after a trial begins, the sponsor, the FDA, or the IRB could suspend or terminate a clinical trial at any time for various reasons, including a belief that the risks to study subjects outweigh the anticipated benefits.

After a device is cleared or approved for marketing, numerous and pervasive regulatory requirements continue to apply. These include:

•establishment registration and device listing with the FDA;

•QSR requirements, which require manufacturers, including third-party manufacturers, to follow stringent design, testing, control, documentation, and other quality assurance procedures during all aspects of the design and manufacturing process;

•labeling regulations and FDA prohibitions against the promotion of investigational products, or the promotion of ‘‘off-label’’ uses of cleared or approved products;

•requirements related to promotional activities;

•clearance or approval of product modifications to 510(k)-cleared devices that could significantly affect safety or effectiveness or that could constitute a major change in intended use of one of our cleared devices, or approval of certain modifications to PMA-approved devices;

•medical device reporting regulations, which require that a manufacturer report to the FDA if a device it markets may have caused or contributed to a death or serious injury, or has malfunctioned and the device or a similar device that it markets would be likely to cause or contribute to a death or serious injury, if the malfunction were to recur;

•correction, removal, and recall reporting regulations, which require that manufacturers report to the FDA field corrections and product recalls or removals if undertaken to reduce a risk to health posed by the device or to remedy a violation of the FDCA that may present a risk to health;

•the FDA’s recall authority, whereby the agency can order device manufacturers to recall from the market a product that is in violation of governing laws and regulations; and

•post-market surveillance activities and regulations, which apply when deemed by the FDA to be necessary to protect the public health or to provide additional safety and effectiveness data for the device.

The FDA has broad regulatory and enforcement powers with respect to medical devices, similar to those for drugs and biologics. The regulations are complex and have tended to become more stringent over time. Regulatory changes could result in additional restrictions or requirements. The FDA enforces these regulatory requirements through, among other means, periodic unannounced inspections. FDORA gives the FDA authority to request medical device facility records in advance of, or in lieu of, inspections. Any failure to comply with applicable regulatory requirements could result in enforcement action by the FDA, which may include any of the following sanctions:

•adverse publicity, warning letters, untitled letters, it has come to our attention letters, fines, injunctions, consent decrees, and civil penalties;

•repair, replacement, refunds, recall, or seizure of products;

•operating restrictions, partial suspension, or total shutdown of production;

•denial of requests for regulatory clearance or PMA approval of new products or services, new intended uses, or modifications to existing products or services;

•withdrawal of regulatory clearance or PMA approvals that have already been granted; or

•criminal prosecution.