a gene therapy to have real impact on patients with hemophilia A. Xconomy detailed the first human data for BioMarin’s gene therapy, BMN270, in April, but the company revealed updated, better results this week. Six of seven patients on a high dose of BMN-270 are producing more than 50 percent of normal Factor VIII anywhere from 12 to 28 weeks after treatment, with a corresponding reduction in the number of bleeding events and Factor VIII infusions needed. BioMarin also hasn’t seen any “clinically relevant sustained rises” in liver enzyme levels—such increases could indicate that patients’ immune systems were attacking their liver cells, which are the ones that take up the therapeutic gene and churn out the new clotting protein. The company aims to start a Phase 2b trial in mid-2017 that chief medical officer Hank Fuchs said in a statement “could support an accelerated approval.” BioMarin shares surged more than 6 percent on the data; Forbes has more here.
—Spark presented the latest data from four patients on a low dose of its hemophilia B gene therapy, SPK-9001. Those four patients had Factor 9 levels as of July 12 of 28 percent, 42 percent, 21 percent, and 35 percent, compared to 28 percent, 41 percent, 26 percent, and 33 percent presented at a medical meeting in June. These data come anywhere from 12 to 31 weeks after treatment, and three of the four haven’t required any infusions since that time. (The fourth patient was treated for a suspected ankle bleed two weeks after getting Spark’s gene therapy.) Spark hasn’t seen any sustained rise in liver enzymes as of yet, and no patients have needed a course of immunosuppressive steroids to counteract an immune reaction.
—UniQure offered data from five patients on a low dose of its hemophilia B gene therapy, AMT-060, nine months after treatment. As of July 22, those five patients had factor IX levels of 7.2 percent, 4.7 percent, less than 2 percent, 6.6 percent, and 2.9 percent (compared to 6.3 percent, 5.4 percent, less than 2 percent, 6.2 percent, and 2.9 percent a month ago). Four patients have stopped using prophylactic treatments. One patient required steroids to curb a rise in liver enzymes. Shares of UniQure have been cut in half since last month as Spark’s program has been seen as superior. But as Leerink Partners’ Michael Schmidt wrote in a note this morning, “multiple gene therapy products may be needed to capture the hemophilia market” given that certain patients have pre-existing antibodies that effectively neutralize specific gene therapies.
—Among the new crop of hemophilia gene therapies, Baxalta’s hemophilia B treatment BAX335 was the first into clinical testing. Shire, which now owns Baxalta, didn’t provide an update on BAX335 just yet—early data presented last year were mixed—but it did tout preclinical work it’s been doing on a hemophilia A program called BAX 888. Sangamo Biosciences also offered a glimpse at a hemophilia A gene editing product. It’ll file papers with the FDA this year to begin clinical trials. Sangamo has already begun a Phase 1 study of a hemophilia B gene editing treatment.
