Ipsen SA / Inspiration Biopharmaceuticals, Inc.

Hemophilia A with Inhibitors / Acquired Hemophilia A; Hemophilia B

Disease Overview

Hemophilia A is an X-linked deficiency of clotting factor VIII; ~30% of severely affected patients develop neutralizing antibodies (inhibitors) to standard FVIII replacement, causing breakthrough bleeds. Acquired hemophilia A is a rare autoimmune condition in adults. Hemophilia B is FIX deficiency. Inhibitor patients require bypassing agents (FEIBA, NovoSeven) or alternative factor sources like recombinant porcine FVIII.

Competitive Landscape

In 2010, hemophilia care was dominated by recombinant FVIII (Baxter's Advate, Bayer's Kogenate, Pfizer's Xyntha) and FIX (Pfizer's BeneFIX, Baxter's plasma-derived) products, while inhibitor patients relied on bypassing agents — Baxter's FEIBA (anti-inhibitor coagulant complex) and Novo Nordisk's NovoSeven (recombinant FVIIa). OBI-1 (recombinant porcine FVIII) was differentiated as a porcine-sequence FVIII offering measurable factor activity in inhibitor patients, addressing both congenital Hemophilia A with inhibitors and acquired hemophilia A — a niche where bypassing agents dominated. IB1001 was positioned as a next-generation recombinant FIX competitor to BeneFIX. The Ipsen-Inspiration partnership ($85M for 20% stake plus $174M milestone tranche for an additional 27%, totaling ~$259M) aimed to build a global hemophilia franchise. The deal ultimately failed: IB1001 hit a Phase 3 clinical hold in 2012, Inspiration filed Chapter 11 in October 2012, and the assets were sold separately — OBI-1 to Baxter (~$700M) and IB1001 to Cangene in 2013. OBI-1 was ultimately approved as Obizur for acquired hemophilia A in 2014.