Ipsen’s Fidrisertib Fails Primary Endpoint in Pivotal Phase II FALKON Trial for Rare Bone Disease FOP

Ipsen's Phase II FALKON trial for fidrisertib did not meet its primary endpoint of reducing new heterotopic ossification (HO) in adults and children with fibrodysplasia ossificans progressiva (FOP) compared to placebo, leading to study closure1234.

Fidrisertib was generally well tolerated with no safety concerns reported12345.

The trial enrolled 113 patients globally over five years; FOP is an ultra-rare genetic disease affecting ~900 patients worldwide, causing progressive bone formation in soft tissues1.

Ipsen stock fell about 2% following the announcement on December 19, 202518.

Company expressed disappointment but plans to use data for ongoing FOP research12.

Sources:

1. https://www.investing.com/news/stock-market-news/ipsen-stock-falls-after-phase-ii-fop-trial-misses-primary-endpoint-93CH-4416565

2. https://www.marketscreener.com/news/phase-ii-trial-failure-for-ipsen-in-fop-ce7d50ddd88af726

3. https://financialpost.com/globe-newswire/ipsen-update-on-phase-ii-falkon-trial-in-patients-with-ultra-rare-bone-disease-fibrodysplasia-ossificans-progressiva-fop

4. https://www.ipsen.com/press-release/ipsen-update-on-phase-ii-falkon-trial-in-patients-with-ultra-rare-bone-disease-fibrodysplasia-ossificans-progressiva-fop-3208286/

5. https://www.marketscreener.com/news/ipsen-s-experimental-drug-for-fop-fails-to-meet-phase-ii-falkon-endpoint-ce7d50ddd980f123

8. https://www.tradingview.com/news/reuters.com,2025:newsml_L8N3XP0E2:0-ipsen-shares-fall-after-failed-trial-on-experimental-fop-drug/