# Regeneron Reports Zero New Abnormal Bone Lesions in Extended Pasatru Trial

- URL: https://stocks.freetheai.org/news/regeneron-reports-zero-new-abnormal-bone-lesions-in-extended-pasatru-trial-2bf447
- Published: 2026-10-12T16:06:00Z
- Category: company_news; sentiment: bullish; impact: medium
- Symbols: [NASDAQ:REGN](https://stocks.freetheai.org/symbols/NASDAQ-REGN)
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Regeneron Pharmaceuticals, Inc. (NASDAQ:REGN) announced long-term 84-week results from its Phase 3 OPTIMA trial for Pasatru, a treatment for adults with fibrodysplasia ossificans progressiva. The study showed zero new abnormal bone lesions formed between weeks 56 and 84 in patients receiving the drug, compared to nine new lesions in the placebo group. Flare-ups of the disease were also lower among patients treated with Pasatru.

Fibrodysplasia ossificans progressiva is an extremely rare genetic disorder where bone grows abnormally in muscles and connective tissue, causing severe loss of mobility and deformity. The U.S. Food and Drug Administration previously approved Pasatru based on 56-week study data. The new 84-week findings demonstrate that the treatment can provide sustained, long-term disease control while maintaining a consistent safety profile, which is critical for managing this lifelong condition.

Regeneron plans to start the Phase 3 OPTIMA 2 trial in children and adolescents with the condition later this year. In addition, European regulators are currently reviewing a submission for the drug, with additional filing plans underway in other countries, including Japan. Regeneron shares traded up 2.52% at $765.40 following the news.

## Key points

- Pasatru demonstrated zero new abnormal bone lesions between weeks 56 and 84 in adults with FOP, compared to 9 in the placebo group.
- Disease flare-ups were lower in patients treated with Pasatru compared to those receiving placebo over the 84-week trial.
- The medication maintained a well-tolerated safety profile consistent with earlier 56-week findings.
- Regeneron plans to begin a Phase 3 study in pediatric and adolescent FOP patients later this year.

## Questions and answers

### What is Pasatru used to treat?

Pasatru is approved to treat adults with fibrodysplasia ossificans progressiva, a rare genetic condition causing abnormal bone formation in soft tissues.

### What were the key results from the 84-week OPTIMA trial extension?

Patients treated with Pasatru had zero new abnormal bone lesions between weeks 56 and 84, compared to nine new lesions in the placebo group.

### What is Regeneron planning next for Pasatru?

Regeneron plans to launch a Phase 3 trial in children and adolescents later this year and is pursuing global regulatory approvals.