This section highlights FDA-related milestones and regulatory updates for drugs developed by United Therapeutics (UTHR).
Over the past two years, United Therapeutics has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
treprostinil, ralinepag, Tyvaso, miroliverELAP, and UKidney. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Select a button below to view the list of FDA events for that drug.
Treprostinil SMI FDA Regulatory Events
Treprostinil SMI is a drug developed by United Therapeutics for the following indication: in PH-COPD.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- treprostinil SMI
- Announced Date:
- October 19, 2026
- Indication:
- in PH-COPD.
Announcement
United Therapeutics Corporation announced that the U.S. Food and Drug Administration (FDA) has granted clearance under the company’s investigational new drug application to proceed with the SUMMIT clinical trial of treprostinil SMI in PH-COPD.
Read Announcement
Ralinepag FDA Regulatory Timeline and Events
Ralinepag is a drug developed by United Therapeutics for the following indication: For the Treatment of Pulmonary Arterial Hypertension.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- ralinepag
- Announced Date:
- October 13, 2026
- Indication:
- For the Treatment of Pulmonary Arterial Hypertension
Announcement
United Therapeutics Corporation announced that two oral and five poster presentations will be presented across its commercial and development portfolio at the CHEST 2026 Annual Meeting hosted by the American College of Chest Physicians taking place October 18-21, 2026, in Phoenix, Arizona.
Read Announcement- Drug:
- ralinepag
- Announced Date:
- August 24, 2026
- Indication:
- For the Treatment of Pulmonary Arterial Hypertension
Announcement
United Therapeutics Corporation announced that the FDA has accepted the New Drug Application (NDA) for ralinepag to treat PAH. The FDA has set a Prescription Drug User Fee Act target action date of June 24, 2027.
Read Announcement- Drug:
- ralinepag
- Announced Date:
- August 24, 2026
- Indication:
- For the Treatment of Pulmonary Arterial Hypertension
Announcement
Ralinepag has not been approved for use in any indication by the FDAand remains investigational for PAH.
Read Announcement- Drug:
- ralinepag
- Announced Date:
- July 29, 2026
- Indication:
- For the Treatment of Pulmonary Arterial Hypertension
Announcement
United Therapeutics Corporation announced that The Lancet has published full results of its ADVANCE OUTCOMES study, available here.Ralinepag has not been approved for use in any indication by the FDAand remains investigational for PAH.
AI Summary
United Therapeutics Corporation announced that The Lancet has published the full results of the long-term, pivotal Phase 3 ADVANCE OUTCOMES study of ralinepag in people with pulmonary arterial hypertension (PAH), most of whom had received previous treatment. The study met its primary endpoint and important secondary endpoints with statistical significance. Results were consistent across patient groups, including those with different disease causes, disease duration, walking distances, functional classes, biomarker levels, and background treatments.
Patients received once-daily, individualized doses of ralinepag or placebo alongside standard PAH therapy. The main measure was the time until a first clinical worsening event, such as death, hospitalization, disease progression, or added prostacyclin treatment. Reported side effects were consistent with known prostacyclin effects, most commonly headache, diarrhea, nausea, and muscle pain. Ralinepag has not been approved by the FDA for any use and remains investigational for PAH.
Read Announcement- Drug:
- ralinepag
- Announced Date:
- May 6, 2026
- Indication:
- For the Treatment of Pulmonary Arterial Hypertension
Announcement
MannKind Corporation announced that it has been developing a dry powder inhalation (DPI) formulation of ralinepag, known as ralinepag DPI (MNKD-1501), for United Therapeutics Corporation nder the companies' expanded license and collaboration agreement announcement from August 2025.
AI Summary
MannKind Corporation said it is developing a dry powder inhalation (DPI) formulation of ralinepag, called ralinepag DPI (MNKD-1501), for United Therapeutics under the companies' expanded license and collaboration agreement announced in August 2025. The work pairs MannKind’s inhalation technology with United Therapeutics’ ralinepag drug candidate.
United Therapeutics highlighted strong pivotal ADVANCE OUTCOMES results for ralinepag and described the DPI as a key part of broader treatment plans for pulmonary arterial hypertension (PAH). The DPI format aims to make the medicine easier to use outside clinics, which could help more patients start and stay on therapy over time.
The collaboration intends to combine clinical benefits of ralinepag with the convenience of a dry powder inhaler to support longer-term real-world use and improve patient experience. Further development plans and timelines were not detailed in the announcement.
Read Announcement- Drug:
- ralinepag
- Announced Date:
- March 2, 2026
- Indication:
- For the Treatment of Pulmonary Arterial Hypertension
Announcement
United Therapeutics Corporation announced that its long-term pivotal phase 3 ADVANCE OUTCOMES study met its primary endpoint, with ralinepag reducing the risk of a clinical worsening event by 55% compared with placebo in patients with PAH (hazard ratio 0.45, 95% CI [0.33-0.62]; p<0.0001).
AI Summary
United Therapeutics announced the phase 3 ADVANCE OUTCOMES study met its primary endpoint: ralinepag reduced the risk of a clinical worsening event by 55% versus placebo (hazard ratio 0.45, 95% CI [0.33–0.62]; p<0.0001). The event‑driven trial enrolled 687 predominantly pretreated patients with pulmonary arterial hypertension (PAH).
Ralinepag also showed significant secondary benefits, increasing the odds of clinical improvement by 47% (p=0.015) and producing improvements in six‑minute walk distance and NT‑proBNP. Benefits were consistent across subgroups, and at baseline about 80% of patients were on dual background therapy while 70% were WHO/NYHA Functional Class II. Treatment was generally well tolerated, with a safety profile consistent with known prostacyclin‑related adverse events and no new safety signals.
United Therapeutics describes ralinepag as a once‑daily oral prostacyclin with potential to change PAH care and plans to present full results and submit an NDA to the FDA in the second half of 2026.
Read Announcement- Drug:
- ralinepag
- Announced Date:
- June 23, 2025
- Indication:
- For the Treatment of Pulmonary Arterial Hypertension
Announcement
United Therapeutics Corporation announced the conclusion of enrollment of the phase 3 ADVANCE OUTCOMES study evaluating the use of an extended-release formulation of ralinepag for the treatment of pulmonary arterial hypertension (PAH).
AI Summary
United Therapeutics Corporation recently announced that enrollment for its phase 3 ADVANCE OUTCOMES study has been completed. This study is evaluating an extended‐release formulation of ralinepag for the treatment of pulmonary arterial hypertension (PAH). A total of 728 participants were enrolled, and they will continue to be monitored through the end of 2025 to track the time to the first clinical worsening event. Top-line results are expected in the first half of 2026.
If successful, ralinepag could be the first once-a-day oral prostacyclin agonist for PAH patients, offering a new treatment option that may change the current treatment approach. United Therapeutics expressed gratitude to the patients and clinical investigators who contributed to this important study.
Read Announcement
Tyvaso (Treprostinil) FDA Regulatory Timeline and Events
Tyvaso (Treprostinil) is a drug developed by United Therapeutics for the following indication: Pulmonary Hypertension associated with Interstitial Lung Disease (PH-ILD).
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Tyvaso (Treprostinil)
- Announced Date:
- September 2, 2026
- Indication:
- Pulmonary Hypertension associated with Interstitial Lung Disease (PH-ILD)
Announcement
United Therapeutics Corporation announced that the FDA has accepted the supplemental New Drug Application (sNDA) for nebulized Tyvaso® (treprostinil) Inhalation Solution to treat IPF. United Therapeutics anticipates the agency's review to be complete in late April 2027.
Read Announcement- Drug:
- Tyvaso (Treprostinil)
- Announced Date:
- August 17, 2026
- Indication:
- Pulmonary Hypertension associated with Interstitial Lung Disease (PH-ILD)
Announcement
United Therapeutics Corporation announced full enrollment of its TETON-PPF study evaluating the use of Tyvaso® (treprostinil) inhalation solution (nebulized Tyvaso) for the treatment of progressive pulmonary fibrosis (PPF). The TETON-PPF study enrolled 754 patients.
Read Announcement- Drug:
- Tyvaso (Treprostinil)
- Announced Date:
- May 18, 2026
- Indication:
- Pulmonary Hypertension associated with Interstitial Lung Disease (PH-ILD)
Announcement
United Therapeutics Corporation announced that the New England Journal of Medicine has published the full results of its TETON-1 study, as well as combined analyses of its TETON-1 and TETON-2 studies, evaluating the use of nebulized Tyvaso for the treatment of IPF.
AI Summary
United Therapeutics said the New England Journal of Medicine published the full results of its TETON-1 study, along with combined analyses of TETON-1 and TETON-2, which tested nebulized Tyvaso for idiopathic pulmonary fibrosis (IPF). The company said the combined data showed statistically significant benefits versus placebo on the main outcome and most key secondary outcomes through 52 weeks.
In the pooled analysis, lung function declined less in the Tyvaso group than in the placebo group. The median change in forced vital capacity was -45.4 mL with Tyvaso compared with -161.7 mL with placebo, a between-group difference of 111.8 mL. TETON-1 results were also reported at the ATS meeting, and benefits were seen across patient subgroups, including those using background therapy, smokers, and patients on supplemental oxygen.
Tyvaso for IPF remains investigational and has not been approved for this use.
Read Announcement- Drug:
- Tyvaso (Treprostinil)
- Announced Date:
- March 30, 2026
- Indication:
- Pulmonary Hypertension associated with Interstitial Lung Disease (PH-ILD)
Announcement
United Therapeutics Corporation announced that its TETON-1 study evaluating the use of nebulized Tyvaso for the treatment of idiopathic pulmonary fibrosis (IPF) met its primary efficacy endpoint, demonstrating superiority over placebo for the change in absolute forced vital capacity (FVC) by 130.1 mL (Hodges-Lehmann [H-L] estimate, 95% confidence interval [CI], 82.2 to 178.1 mL; p <0.0001) from baseline to week 52.
AI Summary
United Therapeutics announced that its TETON-1 study of nebulized Tyvaso (treprostinil) met the primary endpoint, showing superiority over placebo for the change in absolute forced vital capacity (FVC) by 130.1 mL (Hodges‑Lehmann estimate; 95% CI, 82.2 to 178.1 mL; p < 0.0001) from baseline to week 52. The treatment also reduced the risk of clinical worsening in patients with idiopathic pulmonary fibrosis.
Integrated analyses of TETON-1 and TETON-2 showed statistically significant effects across the primary and most secondary endpoints, reinforcing the consistency of the results. Benefits were observed across subgroups, including patients on background antifibrotic therapy, different smoking statuses, and those using supplemental oxygen. Tyvaso was generally well tolerated, with a safety profile consistent with known prostacyclin-related adverse events and no new safety signals.
United Therapeutics plans to seek priority review of a supplemental New Drug Application to the FDA by the end of this summer.
Read Announcement- Drug:
- Tyvaso (Treprostinil)
- Announced Date:
- March 11, 2026
- Indication:
- Pulmonary Hypertension associated with Interstitial Lung Disease (PH-ILD)
Announcement
United Therapeutics Corporation announced that the New England Journal of Medicine has published full results of its phase 3 TETON-2 study evaluating the use of nebulized Tyvaso for the treatment of IPF. The publication is available online at NEJM.org.
AI Summary
United Therapeutics announced that the New England Journal of Medicine has published full results of the phase 3 TETON-2 study evaluating nebulized Tyvaso for idiopathic pulmonary fibrosis (IPF); the paper is available online at NEJM.org. Study authors reported TETON-2 is the first trial to show an inhaled therapy slowed fibrosis progression as measured by change in forced vital capacity (FVC) at week 52. Benefits were seen across subgroups, including patients using background antifibrotic drugs (nintedanib or pirfenidone), smokers, and those on supplemental oxygen.
The randomized trial enrolled 593 patients (Tyvaso n=298, placebo n=295) with a mean age of 71.7 years; baseline percent predicted FVC was 76.8% and 75.4% were on background antifibrotic therapy. Treatment was well tolerated, with mostly mild-to-moderate adverse events—cough, headache, and diarrhea—and no new safety signals. An open-label extension is ongoing to assess long-term safety. If approved, nebulized Tyvaso would be the first inhaled anti-fibrotic for IPF.
Read Announcement- Drug:
- Tyvaso (Treprostinil)
- Announced Date:
- September 19, 2025
- Indication:
- Pulmonary Hypertension associated with Interstitial Lung Disease (PH-ILD)
Announcement
United Therapeutics Corporation announced today that it will host a webcast to review data from the successful TETON-2 pivotal study evaluating the use of nebulized Tyvaso® (treprostinil) Inhalation Solution for the treatment of idiopathic pulmonary fibrosis (IPF) on Sunday, September 28, 2025, at 12:30 p.m. Eastern Time.
AI Summary
United Therapeutics Corporation will host a live webcast on Sunday, September 28, 2025, at 12:30 p.m. Eastern Time to review results from its pivotal TETON-2 study of nebulized Tyvaso® (treprostinil) Inhalation Solution for idiopathic pulmonary fibrosis (IPF). The webcast follows presentation of the data at the European Respiratory Society Congress.
During the event, Dr. Steven D. Nathan, Chair of the TETON Steering Committee, will discuss how TETON-2 met its main goal by showing significant improvement in absolute forced vital capacity (FVC) versus placebo. He will be joined by Leigh Peterson, Ph.D., Peter Smith, Pharm.D., and CQ Deng, Ph.D., M.D., who will highlight secondary endpoints, safety findings, and next steps for the global TETON program.
Investors, clinicians, and patients can access the live webcast and a rebroadcast (available for one year) on United Therapeutics’ website at https://ir.unither.com/events-and-presentations.
Read Announcement- Drug:
- Tyvaso (Treprostinil)
- Announced Date:
- February 4, 2025
- Indication:
- Pulmonary Hypertension associated with Interstitial Lung Disease (PH-ILD)
Announcement
United Therapeutics Corporation announced full enrollment of the TETON 1 study evaluating the use of Tyvaso® (treprostinil) inhalation solution (nebulized Tyvaso) for the treatment of idiopathic pulmonary fibrosis (IPF).
AI Summary
United Therapeutics Corporation announced that enrollment for the TETON 1 study is now complete. This important Phase 3 trial is evaluating nebulized Tyvaso® (treprostinil) for treating idiopathic pulmonary fibrosis (IPF) in the United States and Canada. A total of 598 patients have been enrolled in this randomized, double-blind, placebo-controlled study, which will run over a 52-week period. The trial aims to assess the safety and effectiveness of nebulized Tyvaso in improving lung function and quality of life for IPF patients, a group with limited treatment options. Top-line data from TETON 1 are expected in the first half of 2026. If the data prove successful, United Therapeutics intends to use the study results to support an FDA filing to add IPF to the approved indications for nebulized Tyvaso, potentially offering a transformative treatment option.
Read Announcement
MiroliverELAP FDA Regulatory Events
MiroliverELAP is a drug developed by United Therapeutics for the following indication: Patients with Acute Liver Failure.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- miroliverELAP
- Announced Date:
- April 8, 2026
- Indication:
- Patients with Acute Liver Failure
Announcement
United Therapeutics Corporation has granted Regenerative Medicine Advanced Therapy (RMAT) designation to the company's investigational miroliverELAP®, an external liver assist product.
AI Summary
United Therapeutics announced that its investigational external liver assist product, miroliverELAP®, was granted Regenerative Medicine Advanced Therapy (RMAT) designation. RMAT status is given to promising regenerative therapies and is intended to speed development and review by increasing FDA support, offering earlier and more frequent interactions, and enabling pathways that can lead to faster patient access if clinical evidence supports safety and effectiveness.
MiroliverELAP is designed to support liver function and address needs created by the shortage of transplantable organs. The company says this program is part of its broader efforts in organ and organ-alternative manufacturing, which include xenotransplantation and regenerative medicine approaches for hearts, kidneys, livers, and lungs. RMAT designation could help United Therapeutics advance clinical development of miroliverELAP more efficiently toward potential use in patients with severe liver disease.
Read Announcement- Drug:
- miroliverELAP
- Announced Date:
- January 26, 2026
- Indication:
- Patients with Acute Liver Failure
Announcement
United Therapeutics Corporation announced positive results from its phase 1 study of miroliverELAP®, an external liver assist product, in patients with acute forms of liver failure, acute-on-chronic liver failure, and severe acute alcoholic hepatitis, collectively called acute liver failure (ALF).2
AI Summary
United Therapeutics announced positive phase 1 results for miroliverELAP, an external liver assist developed by its Miromatrix unit. MiroliverELAP uses an external blood circuit and a bioengineered liver made by seeding a decellularized pig scaffold with human endothelial and liver cells from donated livers not suitable for transplant.
Five ALF patients who were not transplant candidates were treated continuously for at least 44 hours. The trial met its main goal of survival during treatment, with no unexpected serious adverse events during a 32-day follow-up. Full results will be published in 2026, and United Therapeutics plans a phase 2 study. About 30% of ALF patients die because they are ineligible for transplant or a donor liver isn't available; an effective external liver support could give crucial time for recovery or bridge patients to transplant.
Read Announcement
UKidney FDA Regulatory Events
UKidney is a drug developed by United Therapeutics for the following indication: Xenotransplantation.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- UKidney
- Announced Date:
- November 3, 2025
- Indication:
- Xenotransplantation
Announcement
United Therapeutics Corporation nnounced the first clinical xenotransplantation in its EXPAND study of the UKidney™ in patients with end-stage renal disease (ESRD). The successful transplant operation was performed at NYU Langone Health.
AI Summary
United Therapeutics announced the first clinical xenotransplantation in its EXPAND study of the UKidney™ in patients with end-stage renal disease (ESRD). The successful operation took place at NYU Langone Health, offering a potential new option beyond lifelong dialysis for patients who may not receive a human donor kidney.
The UKidney is a pig kidney modified with 10 gene edits: six human genes promote immune acceptance and compatibility, while four porcine genes are knocked out to lower rejection risk and control organ growth. This investigational approach could address the critical shortage of transplantable organs and bring new hope to those on waiting lists.
EXPAND (NCT06878560) is a multicenter, open-label safety and efficacy study designed as a seamless phase 1/2/3 trial to support a Biologics License Application. Initial cohorts include six transplants at two centers, with ongoing follow-up for survival, kidney function, and safety over 24 weeks and throughout participants’ lives.
Read Announcement- Drug:
- UKidney
- Announced Date:
- February 3, 2025
- Target Action Date:
- H1 2025
- Estimated Target Date Range:
- January 1, 2025 - June 30, 2025
- Indication:
- Xenotransplantation
Announcement
United Therapeutics Corporation announced that First xenotransplant is expected to occur around mid-year 2025
AI Summary
United Therapeutics Corporation has received clearance from the U.S. FDA to begin a first-in-human clinical trial using its investigational xenokidney, called UKidney™, derived from a genetically modified pig. This study targets patients with end-stage renal disease who have limited transplant options and may not be eligible for a conventional kidney transplant. The trial intends to enroll up to 50 participants, starting with an initial cohort of six individuals. A significant milestone in this initiative is that the first xenotransplant is expected to take place around mid-year 2025. The study will assess both the safety and efficacy of the UKidney transplant, with participants receiving post-transplant follow-up that includes regular monitoring of kidney function and checks for infections. United Therapeutics hopes that this innovative approach will provide a promising alternative to lifelong dialysis for many patients.
Read Announcement- Drug:
- UKidney
- Announced Date:
- February 3, 2025
- Indication:
- Xenotransplantation
Announcement
United Therapeutics Corporation announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug application (IND) to initiate a clinical study of the company's investigational UKidney™ derived from a 10 gene-edited source pig.
AI Summary
United Therapeutics Corporation announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application to begin a clinical study of its investigational UKidney™, an organ derived from a 10 gene-edited source pig. This study is designed to evaluate the safety and effectiveness of the UKidney in patients with end-stage renal disease (ESRD) who are not eligible for a conventional kidney transplant. Initially, six patients will receive the xenotransplant, with the potential to expand the trial to 50 participants. The aim is to gather data that will support a future Biologics License Application (BLA) submission to the FDA. The first xenotransplant under this trial is expected to be performed around mid-year 2025, offering a promising therapeutic alternative for patients reliant on dialysis.
Read Announcement
