Alnylam Says Single Injection Of RNAi Therapy Cuts Alzheimer's-Linked Proteins By 65%, Stock Soars

Alnylam Pharmaceuticals Inc ALNY announced updated interim results for the ongoing single ascending dose portion of the Phase 1 study of ALN-APP for Alzheimer's disease and cerebral amyloid angiopathy (CAA). 

ALN-APP is an investigational RNAi therapeutic to demonstrate gene silencing in the human brain under development in collaboration with Regeneron Pharmaceuticals Inc REGN.

In this study to date, single doses of ALN-APP have been well tolerated. All adverse events were mild or moderate in severity. 

Cerebrospinal fluid (CSF) white blood cell count and total protein levels showed no remarkable elevations from baseline. 

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

Routine laboratory assessments (hematology, serum chemistry, liver function, urinalysis, coagulation) and preliminary data for the exploratory biomarker neurofilament light chain (NfL) did not reveal any significant abnormalities. 

Patients treated with a single dose of 75mg ALN-APP experienced a rapid and sustained reduction in cerebrospinal fluid of both soluble APPα (sAPPα) and soluble APPβ (sAPPβ), biomarkers of target engagement, with maximum reductions of 84% and 90%, respectively. 

Mean reductions in sAPPα of greater than 55% and sAPPβ greater than 65% were sustained at six months after a single dose. 

Further exploration of single doses of ALN-APP is ongoing in Part A. In addition, the safety review committee has recommended initiating Part B, the multiple-dose part of the study. 

Part B will enroll patients from Part A and has already received regulatory approval to proceed in Canada, where most of the Part A clinical trial patients were enrolled. 

The multiple dose part of the study remains on partial clinical hold in the U.S. due to findings observed in prior non-clinical chronic toxicology studies.

Price Action: ALNY shares are up 9.62% at $216.07 on the last check Monday.