Sanofi Cancels JAK2 Development

Sanofi has halted all clinical trials and has canceled plans for regulatory filings for  its investigational JAK2 inhibitor, fedratinib (SAR302503). The move follows a thorough risk-benefit analysis, including consultation with the FDA, study investigators, independent expert neurologists and neuro-radiologists.

There have been recent reports of cases consistent with Wernicke’s encephalopathy in patients participating in fedratinib clinical trials, which led the FDA to direct Sanofi to put all fedratinib trials on clinical hold while the company thoroughly investigated these cases to ensure patient safety. Sanofi took immediate action, requesting that study investigators discontinue fedratinib treatment for patients in the trials. The company has subsequently determined that the risk to patient safety outweighed the benefit that fedratinib would bring to patients.

“We are deeply disappointed to have to discontinue development of fedratinib, especially given the needs of this difficult-to-treat patient population and the earlier promise shown for this therapy, but patient safety is our top priority and drove this decision,” said Tal Zaks, MD, Ph.D., vice president, head of Development and Interim Head of Sanofi Oncology.
 
Sanofi has notified investigators of all ongoing fedratinib trials, as well as health authorities, of its decision to halt the trials. Patients currently in fedratinib trials should consult with their treating physician to determine the best alternative course of therapy for their myelofibrosis.

Fedratinib is a novel, investigational JAK2 inhibitor that was under development by Sanofi Oncology for the treatment of the three main types of myeloproliferative neoplasms: primary myelofibrosis, including those previously treated with ruxolitinib; polycythemia vera; and essential thrombocythemia.