Alnylam - Regeneron Partnered Alzheimer's Candidate's Initial Data Sounds Promising, Analyst Says

Alnylam Pharmaceuticals Inc ALNY and its partner Regeneron Pharmaceuticals Inc REGN announced preliminary data from their Phase I study of their experimental drug dubbed ALN-APP. 

ALN-APP is an investigational RNAi therapeutic targeting amyloid precursor protein (APP, a brain protein) in development for Alzheimer's disease and cerebral amyloid angiopathy (CAA).

Patients treated with single-dose ALN-APP experienced dose-dependent, rapid and sustained reduction in cerebrospinal fluid of both soluble APPα (sAPPα) and APPβ (sAPPβ), biomarkers of target engagement, with a maximum reduction of 84% and 90%, respectively.

Further exploration of single-doses of ALN-APP is ongoing in Part A of the Phase 1 study (Canada, Netherlands, U.K., and U.S.) to evaluate longer-term safety and duration of action and to identify the multi-dose regimen for Part B

Alnylam and Regeneron are already moving into the second half of the Phase I study in Canada. But the FDA has placed a partial clinical hold on the next step of the study in the U.S. due to "chronic toxicology findings from non-clinical studies." 

Adverse events in the human study were "mild to moderate" and "quite similar to placebo," the company said.

William Blair writes that though the partial hold is undoubtedly disappointing, the update is highly encouraging for the Alnylam siRNA platform in CNS disorders if the partial clinical hold can be navigated.

The analyst notes that the data is early, and the clinical hold will likely cause volatility for Alnylam. Overall, it sees the topline data as promising to build a CNS pipeline, reiterating Outperform rating.

Price Action: ALNY shares are down 1.39% at $194.78, and REGN shares are up 0.58% at $782.55 on the last check Thursday.

Photo by Gerd Altmann from Pixabay