Alnylam builds out case for patisiran, showing sharp drop in hospitalization, mortality

Alnylam has presented a fresh take on its phase 3 patisiran data as it builds out its case ahead of an anticipated landmark approval. The new angle comes from an exploratory post hoc analysis which linked the RNAi therapy to a 50% drop in all-cause hospitalization and mortality over placebo.

Cambridge, Massachusetts-based Alnylam looked at the composite rate of hospitalization and mortality among hereditary ATTR amyloidosis patients who received patisiran or placebo over 18 months. The patients had to suffer such an event within 28 days of the last dose of study drug to be included in the analysis. Alnylam saw a similarly-sharp drop when it limited the analysis to cardiac hospitalization events and all-cause mortality.

The exploratory, post hoc nature of the analyses means the findings need to be approached with a degree of caution. But they are complementary, not central, to Alnylam’s case in support of patisiran, which rests on the previously disclosed improvement in a score of neurological impairment.

That data point will take center stage when patisiran is reviewed by regulators, but the need to get the support of payers and fend off possible competition from Akcea and Ionis’ rival drug inotersen means extra evidence could come in useful down the line. 

Alnylam is presenting the post hoc mortality analysis at the American Academy of Neurology 2018 Annual Meeting alongside other looks at the data. One of the other takes presented by the biotech at the meeting is a quartile analysis of baseline scores of neurological impairment. The analysis linked patisiran to improved outcomes regardless of the baseline score, prompting Alnylam to talk up the prospect of intervening early in disease progression.

Such granular detaIls as when to start patients on patisiran will start to come into play if the drug gets approved. The FDA has penciled in Aug. 11 as the PDUFA action date and stated it does not plan to hold an advisory committee meeting covering the application.