In its race to be the first to submit a gene therapy for review in hemophilia, BioMarin Pharmaceutical is dropping development of a lower dose of its valrox treatment amid plans to get its applications into the hands of regulators before the end of the year.
Through its second-quarter financial update, the company said it would move forward with bleeding control data spanning three years from a phase 1/2 study as well as a recently completed phase 3 interim analysis in patients with hemophilia A.
Under its full name, valoctocogene roxaparvovec, BioMarin plans to present its accelerated approval requests to the FDA and European Medicines Agency in the fourth quarter of 2019—making it the first gene therapy product to be reviewed in any hemophilia indication.
It opted to cease work on valrox’s lower, 4e13 vector genomes per kilogram dose “given the overwhelming preference by patients to be treated with the 6e13 vg/kg dose,” the company said in a statement.
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The program’s next update should be the completion of enrollment in its phase 3 study early in the fourth quarter of 2019, with one-year data from 130 patients coming by the end of 2020 or in early 2021, BioMarin’s R&D president Henry Fuchs said on a conference call with investors.
However, that gap between the phase 3 study and the FDA and EMA’s review timelines means BioMarin could see its primary bleeding data read out during or shortly after valrox’s initial launch. Valrox represents the largest market the company has entered to date, according to CEO J.J. Bienaimé.
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Its main competition could come from Pfizer and Sangamo Therapeutics’ hemophilia A gene therapy SB-525. Though slightly behind, the companies recently offered a look at early data from the first patients to receive the highest dose of the therapy, which is designed to deliver a copy of the factor VIII gene to liver cells.
One of the two patients demonstrated normal FVIII activity after seven weeks, while the other had yet to reach the data cutoff but received the treatment more recently. None of the high-dose patients have suffered bleeding events, though longer-term follow up and safety data are needed.