encouraged by what Alnylam has seen so far. He says given that untreated patients typically worsen by about 18 points on the mNIS+7 scale over a year, anything less than a 9-point increase for patisiran patients would have been a “pretty powerful” takeaway from the small Phase 2 extension study it’s reporting on today. Patisiran performed better than that.
“The fact that we saw a decrease really points to a halting of [disease] progression here,” he says. “It bodes incredibly well for the powering of Apollo [Alnylam’s Phase 3 trial].”
For example, Greene says, natural history data and other scientific literature suggests that placebo patients’ mNIS+7 scores would jump by 27 points in 18 months; if patisiran patients had even a 16 to 17 point increase over the course of treatment, Alnylam would hit statistical significance, though Greene adds—“obviously by looking at these data, we, the investigators—and, you can bet, the physicians—sure hope it’s better than that.”
FAP is a form of transthyretin amyloidosis, an inherited condition in which amyloid proteins build up in tissues of the body and cause damage to the nerves, heart, and other organs. About 10,000 people have the nerve-damaging form, FAP, and they tend to live another 5 to 15 years after symptoms crop up (another form, affecting the heart, is more prevalent).
The only treatment options for FAP patients are a liver transplant, or Pfizer’s tafamidis (Vyndaqel), which is approved in Europe but not in the U.S. Alnylam is also in a race with another maker of RNA-based drugs, Isis Pharmaceuticals (NASDAQ: [[ticker:ISIS]]), which is co-developing a treatment with GlaxoSmithKline called ISIS-TTRrx that’s also in late-stage testing. Data from that trial are also expected in 2017. (Isis hasn’t disclosed any data from the therapy in actual FAP patients as of yet.)
Patisiran’s progress is a touchstone for the RNAi field, which now appears as close as it’s ever been to producing an approved drug. The concept is essentially to silence disease-causing genes before they make the proteins that trigger diseases by introducing short, synthetic strands of RNA into cells. RNAi’s history has been a roller coaster, largely due to solving the technical challenge of getting large RNAi molecules to their targets—and Alnylam knows that better than anyone. Its shares were worth just $6 apiece a few years ago, when several pharmaceutical companies backed out of the field. Now, indicative of the field’s resurgence, shares are worth more than $118.
Sanofi’s Genzyme unit has commercial rights to patisiran everywhere except North America and Western Europe.
Alnylam is hosting a conference call later this morning to discuss the data.
