Alnylam, Sanofi flag another promising step forward for PhIII hemophilia drug

Alnylam $ALNY and its partners at Sanofi $SNY say their hemophilia drug fitusiran has taken a promising step forward in the clinic, clearing another leg of a Phase II study with continued evidence of safety and efficacy that backs its recent move into a pivotal trial.

Fitusiran was one of the key reasons why Sanofi decided to buy into Alnylam and its RNAi approach with a $700 million equity deal three years ago. And it’s also central now to Alnylam’s case to investors that its Phase III pipeline is growing with promising new meds.

Akin Akinc

Appearing at the International Society of Thrombosis and Haemostasis Congress in Berlin today, investigators noted that the 33 patients taking fitusiran passed the 11-month median mark on dosing with an annualized bleeding rate of 1 in the full group and 0 among the 11 patients who had developed inhibitors to standard therapies. Most of the patients suffered from hemophilia A, though there were also 6 hemophilia B patients in the study.

Significantly, the median annualized bleed rate was 12 in all patients pre-study, and 38 in inhibitor patients.

“We are quite encouraged,” Alnylam’s Akin Akinc – the general manager of the program – told me in a preview of today’s data update.

There was a decline in the number of patients who remained bleed-free in the study, down to 48%. But Akinc notes that isn’t unexpected.

“We are pretty pleased with that number,” he says. You should expect to see that figure trickle down, he adds, “that number will never go up.”

As investigators have already noted, there was an issue with elevated liver enzymes in the study, though Akinc says the one discontinuation that prompted was in a patient with hep C, which could have been an issue. Another patient on the drug discontinued due to seizure and confusion in a patient with seizure disorder.

I asked him about emicizumab before Shire issued its broadside against the Roche drug. But Akinc wasn’t in a critical frame of mind. He offered a “tip of the hat” to Roche on the data so far and noted that it is hard to compare drugs without a head-to-head study. That said, he added, the hemophilia community is now seeing a variety of different therapies coming through late-stage development, including among gene therapy players. And that will benefit everyone.

Alnylam and Sanofi announced on Friday that the fitusiran Phase III was getting underway. Its importance was magnified considerably after the Cambridge, MA-based biotech had to scrap its number 2 drug due to safety concerns.

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Recursion Pharmaceuticals Salt Lake City, UT
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