Centessa takes a step towards a new haemophila mechanism

 Haemophilia gene therapy developers look out. New competition could be on the horizon from Centessa Pharmaceuticals’ novel project SerpinPC, which today yielded promising phase 2 results. There are reasons for caution: the dataset was small, comprising just 22 patients, with no placebo control. But an 88% reduction in all bleeds with the highest dose, 1.2mg/kg, at 12 weeks versus baseline got investors’ attention, pushing Centessa shares up 16% this morning. The group hopes that SerpinPC could become a one-size-fits-all therapy, regardless of haemophilia type, severity or inhibitor status. Centessa now needs to prove the once-monthly project’s benefit in larger registrational studies, but did not give many details during a conference call today. Thrombotic events will also be closely watched given SerpinPC’s mechanism. The project is an activated protein C inhibitor designed to restore levels of prothrombinase – this in turn generates thrombin, which is needed for blood clotting. On this point, Centessa execs said they were encouraged by unchanged levels of D-dimer, a marker of excess thrombin. Even if SerpinPC succeeds it will have a hard time catching Roche’s approved haemophilia A therapy Hemlibra, which is forecast to sell around $5bn by 2026, according to Evaluate Pharma sellside consensus.

The top-five haemophilia products in 2026
Product/project	Company	Mechanism	Disease subtype	2026e sales ($m)
Hemlibra	Roche/Chugai	Anti-factor IXa & X bispecific MAb	Haemophilia A	5,590
NovoSeven	Novo Nordisk	Recombinant Factor VII	Haemophilia A & B	796
Valoctocogene roxaparvovec (valrox)	Biomarin	AAV5 factor VIII gene therapy	Haemophilia A	695
Kogenate	Bayer	Recombinant Factor VIII	Haemophilia A	663
Idelvion	CSL	Factor IX-albumin fusion protein	Haemophilia B	661
Source: Evaluate Pharma. https://www.evaluate.com/vantage/articles/news/snippets/centessa-takes-step-towards-new-haemophila-mechanism