Ipsen receives Complete Response Letter for palovarotene, an investigational treatment for fibrodysplasia ossificans progressiva

Ipsen receives Complete Response Letter for palovarotene, an investigational treatment for fibrodysplasia ossificans progressiva

  • The CRL is related to the U.S. FDA’s previous request for additional information on palovarotene clinical trial data
  • Ipsen anticipates responding to the request in the first quarter of 2023

PARIS, FRANCE, 23 December 2022 – The U.S. Food and Drug Administration (FDA) issued a Complete Response Letter (CRL) regarding the New Drug Application for palovarotene, an investigational treatment for the reduction of new abnormal bone formation (heterotopic ossification) in people living with fibrodysplasia ossificans progressiva (FOP). The CRL is related to the regulatory agency’s previous request for additional information on palovarotene clinical trial data communicated to Ipsen in October 2022, which is not a request for additional efficacy or safety data beyond existing studies. Ipsen anticipates responding to the request in the first quarter of 2023 with an expected six-month FDA review cycle. The FDA has not announced a rescheduled date for the Endocrinologic and Metabolic Drugs Advisory Committee meeting for investigational palovarotene.

“Although this extends the review timeline for palovarotene, we continue to work with the FDA to provide the requested information and believe that investigational palovarotene has the potential to be an innovative treatment to reduce new abnormal bone formation to slow the progression of FOP,” said Howard Mayer, Executive Vice President and Head of Research and Development for Ipsen. “Currently, people living with FOP in the U.S. have no approved treatment option to slow the progression of the disease and this remains our reason for being steadfast in our pursuit of bringing this potential treatment option for FOP.”

FOP is an ultra-rare disease that causes permanent and continuous bone formation in soft and connective tissues like muscles, tendons and ligaments, also known as heterotopic ossification or HO.1 As bone continuously accumulates over time in joints and other areas of the body with flare-up episodes causing rapid bone formation, FOP severely restricts mobility and function.2 FOP impacts the lives of fewer than an estimated 400 people in the U.S. and 900 people globally.3 Due to abnormal bone formation, in childhood and early adulthood people living with FOP may lose the permanent ability to move their neck, back, shoulders, chest, legs and arm joints.Without disease-modifying treatment, palliative care is the only treatment option and the median life expectancy is 56 years with untimely death caused by bone formation around the ribcage leading to breathing problems and cardiorespiratory failure.2

About palovarotene  

Palovarotene is authorized for use in appropriate patients in Canada and United Arab Emirates where it is marketed as SohonosTM (palovarotene capsules).4 Investigational palovarotene is under review with a number of regulatory authorities.

About Ipsen 

Ipsen is a global, mid-sized biopharmaceutical company focused on transformative medicines in Oncology, Rare Disease and Neuroscience. With Specialty Care sales of €2.6bn in FY 2021, Ipsen sells medicines in over 100 countries. Alongside its external-innovation strategy, the Company’s research and development efforts are focused on its innovative and differentiated technological platforms located in the heart of leading biotechnological and life-science hubs: Paris-Saclay, France; Oxford, U.K.; Cambridge, U.S.; Shanghai, China. Ipsen has around 5,000 colleagues worldwide and is listed in Paris (Euronext: IPN) and in the U.S. through a Sponsored Level I American Depositary Receipt program (ADR: IPSEY). For more information, visit ipsen.com

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  1. Kaplan FS, et al. The medical management of fibrodysplasia ossificans progressiva: current treatment considerations. Proc Intl Clin Council FOP 1:1-111, 2019.
  2. Pignolo, RJ et al. Bone. 2020; 134:115274.
  3. Liljesthröm M, Pignolo RJ, Kaplan FS. Epidemiology of the Global Fibrodysplasia Ossificans Progressiva (FOP) Community. J Rare Dis Res Treat. (2020) 5(2): 31-36
  4. Ipsen Press Release 24 January 2022. Available at https://www.ipsen.com/press-releases/health-canada-approves-ipsens-sohonos-palovarotene-capsules-as-the-first-approved-treatment-for-fibrodysplasia-ossificans-progressiva/


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