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December 2025: Ipsen ends FALKON clinical trial

Fidrisertib was an oral investigational medication developed as a potential treatment for FOP. In December 2025, Ipsen notified the FOP community that fidrisertib did not meet its primary endpoint of reducing new heterotopic ossification (HO) and that the FALKON trial is coming to an end.

This highly selective ALK2 inhibitor was designed to block the overactive signaling pathway that causes soft tissues to transform into bone. While the goal was to prevent the formation of extra-skeletal bone and reduce painful flare-ups, the study results indicated the medication did not meet the necessary effectiveness goals to continue development.

If you participated in this trial, we thank you for your participation, as your contribution has provided invaluable data for the future of FOP research.

To read Ipsen’s letter to the community: Letter

To read Ipsen’s press release: Ipsen

SOHONOS by Ipsen

Sohonos (palovarotene) is the first treatment developed to reduce new abnormal bone formation in FOP. It has been approved for FOP in Canada (since January 2022), the US (since August 2023) and Australia (November 2023).  In the EU/UK it is not approved for the treament of FOP, because regulators judged the evidence and safety-profile did not meet their requirements. For people in the UK with FOP, this means the drug is not yet an authorised routine treatment option.

Read the EMA’s decision on Sohonos: Overview

You can read more here: Sohonas: a summary

Visit the Sohonos website: https://www.sohonos.com/for-patients