Analyst Says Alnylam's New Patisiran Data Shows Disease Slowing With Early Intervention, But Survival Benefit Remains Of Interest

Alnylam Pharmaceuticals Inc ALNY released new results from an interim analysis of exploratory data from the open-label extension (OLE) period of the APOLLO-B Phase 3 study of patisiran, for the treatment of transthyretin-mediated (ATTR) amyloidosis with cardiomyopathy. 

The company previously announced that APOLLO-B achieved its primary endpoint and met its first secondary endpoint during the 12-month double-blind (DB) period. It has submitted the 18-month data to the FDA as an amendment to the supplemental New Drug Application.

The 18-month findings indicate that the favorable effects on functional capacity, health status, and quality of life observed during the DB period were sustained with continued patisiran treatment during the OLE period. 

Patients treated with patisiran through 18 months also appear to have maintained relative stability of NT-proBNP and Troponin I levels, measures of cardiac stress and injury, respectively. 

Patisiran demonstrated an encouraging safety profile.

Most adverse events (AEs) were mild or moderate in severity. The most common treatment-related AE was infusion-related reactions.

The FDA has set an action date of October 8, 2023, and noted that they plan to convene a Cardiovascular and Renal Drugs Advisory Committee meeting.

The FDA has approved Patisiran as Onpattro for polyneuropathy of hereditary ATTR amyloidosis in adults.

William Blair writes that these results maintain the clear beneficial profile of Onpattro in these patients, although the degree of improvement in the switch patients is less than that seen in the initial six months of Onpattro treatment in the double-blind period.

This illustrates that the disease-modifying treatment is unlikely to be regenerative and earlier intervention is likely to lead to improved outcomes, as is often the case with progressive pathologies, writes the analyst.

Price Action: ALNY shares closed higher by 1.22% at $193.06 on Monday.