{"id":996714,"date":"2026-08-19T14:01:05","date_gmt":"2026-08-19T18:01:05","guid":{"rendered":"https:\/\/www.marketnewsdesk.com\/index.php\/pasatru-garetosmab-grts-first-and-only-fda-approved-treatment-demonstrating-reduction-in-new-heterotopic-ossification-ho-lesions-and-clinician-assessed-flare-ups-in-a-placebo-controlled-t\/"},"modified":"2026-08-19T14:01:05","modified_gmt":"2026-08-19T18:01:05","slug":"pasatru-garetosmab-grts-first-and-only-fda-approved-treatment-demonstrating-reduction-in-new-heterotopic-ossification-ho-lesions-and-clinician-assessed-flare-ups-in-a-placebo-controlled-t","status":"publish","type":"post","link":"https:\/\/www.marketnewsdesk.com\/index.php\/pasatru-garetosmab-grts-first-and-only-fda-approved-treatment-demonstrating-reduction-in-new-heterotopic-ossification-ho-lesions-and-clinician-assessed-flare-ups-in-a-placebo-controlled-t\/","title":{"rendered":"Pasatru\u2122 (garetosmab-grts) First and Only FDA-approved Treatment Demonstrating Reduction in New Heterotopic Ossification (HO) Lesions and Clinician-Assessed Flare-ups in a Placebo-controlled Trial in Adults with Fibrodysplasia Ossificans Progressiva (FOP)"},"content":{"rendered":"
\n

\n FOP is an ultra-rare genetic disorder characterized by rogue bone formation that infiltrates muscles, tendons, ligaments and other connective tissues, resulting in significant disability\u00a0<\/strong>\n <\/p>\n

\n Approval based on results from the OPTIMA trial demonstrating a 90% or greater reduction in new HO lesions at 56 weeks with a dramatic reduction in clinician-assessed flare-ups in adults with FOP<\/strong>\n <\/p>\n

TARRYTOWN, N.Y., Aug. 19, 2026 (GLOBE NEWSWIRE) — Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) today announced the U.S. Food and Drug Administration (FDA) has granted approval for Pasatru\u2122<\/sup>\u00a0(garetosmab-grts) to reduce formation of new heterotopic ossification (HO) lesions and clinician-assessed flare-ups in adults with fibrodysplasia ossificans progressiva (FOP). Recognizing the significant mobility challenges faced by many people with FOP, Pasatru can be administered across a range of care settings, including home infusion where appropriate. The recommended starting dosage is based on weight at 10 mg\/kg and is given intravenously over 60 minutes once monthly (every four weeks) but may be decreased to a 3 mg\/kg infusion over 60 minutes once monthly if not tolerated. Pasatru is a VelocImmune<\/em>\u00ae<\/em><\/sup>-derived, fully human monoclonal antibody that blocks Activin A, a protein that Regeneron scientists discovered<\/a> to be critical in the development of HO lesions in people with FOP.<\/p>\n

FOP is an ultra-rare genetic disorder in which muscles, tendons, ligaments and other connective tissues are progressively infiltrated by rogue bone formation, a process known as HO. HO of the jaw, spine, hip and rib cage can make basic actions such as speaking, eating, walking or breathing difficult, and the dysfunction of these structures can lead to escalating loss of mobility. Worldwide, approximately 900 people are diagnosed with FOP, and most patients are wheelchair-bound by age 30 with the median age of survival being 56.<\/p>\n

\u201cFor people living with FOP, every irregular new bone formation is a step toward disability and potential loss of mobility,\u201d said Dr. Kathryn Dahir, Professor in the Department of Internal Medicine, Division of Endocrinology, Diabetes, and Metabolism at Vanderbilt University, and a primary investigator for the OPTIMA trial. \u201cWith the ability to reduce the number of new bone lesions and flare-ups, we now have a new treatment that can positively affect patients.\u201d<\/p>\n

\u201cFOP is a relentless, restrictive condition that severely impacts the lives of those diagnosed and their families,\u201d said Michelle Davis, Executive Director of the International FOP Association. \u201cThis approval is monumental for our community, providing a vital new therapy that can have a significant impact on the life of someone with FOP.”<\/p>\n

Pasatru was granted approval based on efficacy and safety data from the positive Phase 3\u00a0OPTIMA<\/a>\u00a0trial evaluating Pasatru in adults with FOP. At 56 weeks, both doses of Pasatru, 10 mg\/kg (n=23) and 3 mg\/kg (n=19), met the primary endpoint and were highly efficacious in reducing the total number of new HO lesions as compared to placebo (n=21), demonstrating a 90% (2 lesions vs. 19 lesions) and 94% (1 lesion vs. 19 lesions) reduction, respectively, as assessed by computed tomography (CT) scan. The number of clinician-assessed flare-ups during this time, a key secondary endpoint, were 9 for Pasatru 10 mg\/kg (88% reduction compared to placebo), 53 for Pasatru 3 mg\/kg (15% reduction compared to placebo), and 66 for placebo. Changes in the proportion of patients with patient-reported flare-ups through week 56 were not significantly different between placebo and Pasatru treatment groups. At 56 weeks, among all 63 people who participated in the trial, serious treatment-emergent adverse events occurred in 2 patients treated with 10 mg\/kg Pasatru, 1 patient treated with 3 mg\/kg Pasatru, and 2 patients treated with placebo. The most common adverse reactions occurring in \u226510% of adults with FOP treated with Pasatru 10 mg\/kg or 3 mg\/kg were abscess, acne, increased hair growth, madarosis (loss of eyebrows), oral ulcers, epistaxis (nosebleeds), folliculitis, paronychia (nail infection), and rash.<\/p>\n

\u201cThe approval of Pasatru is the culmination of decades of pioneering research that Regeneron has pursued alongside the FOP community, rooted in our discovery of the role that Activin A plays in driving this disease,\u201d said George D. Yancopoulos, M.D., Ph.D., Board co-Chair, President and Chief Scientific Officer at Regeneron. \u201cPeople living with FOP have needed a new treatment option for this devastating condition far too long, much like many others living with a rare disease. This unprecedented milestone embodies our broader mission to continue delivering new options for those who have long faced limited treatment options and our relentless commitment to bringing scientific breakthroughs to families, no matter the prevalence of the condition they manage.\u201d<\/p>\n

Regeneron is committed to supporting people living with rare diseases. Regeneron\u2019s myRARE\u2122 program offers resources to help patients and healthcare providers, including product information, insurance benefit verification, and information about potential financial support. To learn about myRARE, visit myRARE.com<\/a> or call 1-833-4my-RARE (1-833-469-7273).<\/p>\n

In the European Union, a regulatory submission for Pasatru is currently under review by the European Medicines Agency. Additional regulatory submissions are planned in countries around the world, including Japan. Pasatru previously received Fast Track designation and Orphan Drug Designation from the FDA, as well as Orphan Designation by the European Medicines Agency in the European Union and the\u00a0Ministry of Health, Labour and Welfare\u00a0in Japan.<\/p>\n

\n About the OPTIMA Clinical Trial<\/strong>\u00a0
OPTIMA is a Phase 3, multi-center, multinational trial to assess the efficacy of\u00a0Pasatru on the reduction of heterotopic bone formation and flares, as well as its safety, tolerability, and pharmacokinetics, in patients with active FOP.\u00a0<\/p>\n

The trial enrolled 63 participants\u00a0aged 18 years and older who have any FOP-causing variant of type I Activin A receptor (ACVR1),\u00a0exhibited\u00a0FOP disease activity or progression of\u00a0HO\u00a0lesions, and had a cumulative analogue joint involvement scale (CAJIS) score at screening of \u226419. CAJIS is a scoring tool used by clinicians to assess the degree of joint involvement, with higher scores\u00a0representing\u00a0a greater degree of disease severity (scale: 0 to 30). Eligible participants were randomized to receive intravenously administered Pasatru 10 mg\/kg,\u00a0Pasatru 3 mg\/kg, or placebo once every four weeks for\u00a056 weeks. Following this, participants could\u00a0elect\u00a0to then continue their originally assigned treatment in a double-blind extension phase for at least\u00a084 weeks\u00a0or\u00a0discontinue\u00a0treatment and enter an observation-only arm.\u00a0<\/p>\n

During the treatment period, efficacy was evaluated through whole body CT scans for HO lesions, physician and patient assessment of flare-ups,\u00a0utilization\u00a0of CAJIS\u202fto rate joint functionality, and observances of change in disease severity.\u00a0Safety assessment includes reports of adverse events, measurement of vital signs, physical examination, and coagulation testing.\u00a0<\/p>\n

A Phase 3 trial of\u00a0Pasatru in adolescents and children with FOP, OPTIMA 2, is planned to begin\u00a0later this year. For more information, visit the\u202fRegeneron\u202fclinical trials website<\/a>, contact clinicaltrials@regeneron.com<\/a> or call +1 844-734-6643.\u00a0<\/p>\n

\n About Pasatru<\/strong>
\n
Regeneron has been engaged in FOP research for decades and helped to\u00a0provide\u00a0fundamental insights into\u00a0the biology and natural history of the disease.\u00a0Regeneron scientists discovered that\u202fActivin A plays a key\u00a0role in FOP<\/a>\u202fby driving HO, the\u00a0main pathology of FOP<\/a>.\u00a0Pasatru is a\u202fVelocImmune<\/em>-derived,\u00a0fully human\u00a0monoclonal antibody that binds and neutralizes Activin A, which is involved in the development of heterotopic bone in people with FOP.\u00a0<\/p>\n

\n IMPORTANT SAFETY INFORMATION<\/strong>\n <\/p>\n

\n What is the most important information I should know about PASATRU?<\/strong>\n <\/p>\n

\n PASATRU can cause serious side effects, including:<\/strong>\n <\/p>\n