Inspiration receives FDA clinical hold order for IB1001 phase III studies on hemophilia B

Ipsen (Paris:IPN) (Euronext: IPN; ADR: IPSEY) announced today that its partner Inspiration Biopharmaceuticals Inc. (Inspiration) was notified by the Food and Drug Administration (FDA) that both clinical trials evaluating the safety and efficacy of IB1001, an investigational intravenous recombinant factor IX (rFIX) therapy for the treatment and prevention of bleeding episodes in people with hemophilia B, were placed on clinical hold.

The clinical hold impacts two ongoing IB1001 clinical trials - a phase III study evaluating the safety and efficacy of IB1001 to treat and prevent bleeding episodes in adults with hemophilia B, and a phase III study evaluating the safety and efficacy of IB1001 to treat and prevent bleeding episodes in previously treated pediatric subjects with hemophilia B. The adult study has completed its primary analysis period. Following the FDA's request, Inspiration has notified clinical sites in the U.S. to hold treatment of patients with IB1001. Inspiration is also sharing the FDA directive with regulators in countries outside of the U.S. where the studies are being conducted.

During the course of routine laboratory evaluations conducted as part of the ongoing phase III clinical trials, Inspiration observed, and reported to the FDA, a trend towards a higher proportion of IB1001 treated individuals developing a positive response to testing of antibodies to Chinese Hamster Ovary (CHO) protein, the product's host cell protein (HCP).

Small amounts of host cell protein are expected and documented in recombinant therapeutic products of all types. Nevertheless, the higher than expected rate of anti-CHO antibody development in people treated with IB1001 has led Inspiration to initiate a thorough investigation.

A total of 86 people with hemophilia B have received IB1001 in clinical studies and, to date, no adverse events (anaphylaxis or other serious allergic type reaction and nephrotic syndrome) related to the development of antibodies to CHO protein have been reported. Furthermore, no relationship has been demonstrated between the development of antibodies to CHO protein and the development of any antibodies to factor IX. Inspiration continues to follow subjects enrolled in clinical trials of IB1001 to collect safety-related information and will share this information with regulators.

While this finding may be a potential safety concern, no evidence suggests a change in the current overall clinical benefit and risk profile of IB 1001.