- Genentech has in hand new clinical results which further underscore the effectiveness of its drug tailored for the roughly one-third of severe hemophilia patients who have developed immunities to other treatments.
- In the late-stage HAVEN 1 study, 62.9% of patients taking the drug — dubbed ACE910 or emicizumab — as a preventative medication had no bleeds across a median observation time of 31 weeks. Conversely, 5.6% of participants who received bypassing agents (BPAs) as prophylaxis didn't experience any treated bleeds.
- Five serious adverse events, comprised of three cases of thrombotic microangiopathy (TMA) and two cases of thromboembolic events (TE), occurred in the experimental arm of the trial. In a June 25 statement, Genentech said those side effects were tied to repeated, high doses of a BPA. Nevertheless, emicizumab's safety profile has been a growing concern, particularly after a patient taking the drug died earlier this year.
As if treating a rare disorder like hemophilia wasn't tricky enough, about 30% of patients with more severe forms of the disease develop what are called inhibitors — antibodies that degrade infused blood clotting proteins.
It's that population Genentech is hoping to tap into with emicizumab, and the return on investment could be extensive should it get a green light from regulators.
Investment bank Jefferies, for instance, expects the drug to reach $5 billion in peak annual sales, and that's a risk-adjusted estimate accounting for a "protracted launch trajectory due to multiple clinical trial read outs needed to build out the label as well as conservative adoption of this therapy," according to a June 26 note.
These new trial results are helping to bolster the drug's path to market as well.
HAVEN 1 is a randomized, open-label study treating 109 hemophilia patients ages 12 and up. Results showed participants who received the Roche subsidiary's drug had an 87% reduction in their bleed rate, the primary outcome, versus those who received on-demand BPAs.
Additionally, emicizumab met several secondary endpoints. Compared to the BPA-only group, patients in the experimental arm showed an 80% reduction in all bleeds, a 92% reduction in treated spontaneous bleeds, an 89% reduction in treated jointed bleeds and a 95% reduction in treated target joint bleeds.
Genentech on Sunday also reported interim results from another late-stage trial, HAVEN 2, that tested the drug in patients under 12 years of age and said they were "consistent" with the outcomes seen in HAVEN 1. One of the 19 children had a treated bleed during the median 12 week observation window. What's more, the data showed that those younger children can receive the same dose of emicizumab as adolescents and adults.