Trust favourite Alnylam approaches key FDA decision
Biotech trust stock favourite Alnylam Pharmaceuticals (Nasdaq:ALNY) should find out later this week whether the FDA will grant approval to its first product, Onpattro (patisiran), for hereditary transthyretin-mediated amyloidosis (or hATTR). In this case, unusually, there is relatively little concern that Onpattro may not receive US approval and the key question is more of what will be the breadth of approval it receives. Specifically, this is whether the label will include hATTR-cardiomyopathy, now that Alnylam is likely to have to face competition from other products in this rare indication.
Alnylam is held by a number of the sector’s specialist investment trusts including Biotech Growth Trust (BIOG, 3.6% of NAV) and BB Biotech (BBB, 3.6% of NAV). It is also the third largest single holding (3.7% of NAV) for Edinburgh Worldwide Investment Trust (EWI), a diversified non-biotech specialist albeit with significant exposure to healthcare stocks.
The FDA has set itself a deadline of 11 August to render a decision on the company’s submission. A few weeks ago, the European Medicines Agency’s CHMP issued a positive opinion on the company’s EU application, which precedes formal approval that is likely in September. The UK’s MHRA subsequently issued the product a positive opinion under its Early Access to Medicines Scheme, allowing UK patients access to the drug ahead of its formal approval. Notably, this covers hATTR amyloidosis patients presenting with symptoms of polyneuropathy and/or cardiomyopathy.
Another important on the horizon is likely to be the presentation of clinical trial data on one of the competing products, Pfizer’s Vyndaqel (tafamidis) for transthyretin cardiomyopathy. Earlier this year, Pfizer reported a positive top-line result in its Phase III Attract trial, but reserved full data for presentation at a scientific meeting: this is now expected at the European Society of Cardiology (ESC) Congress on 27 August.
Pfizer has previously reported that its Phase III ATTR-ACT study showed a statistically significant reduction in the combination of all-cause mortality and frequency of cardiovascular-related hospitalisations, the primary endpoint, compared with placebo at 30 months. The ATTR-ACT study included both the hereditary and the wild-type forms of the disease, whereas Alnylam’s Onpattro studies only included hereditary ATTR. Analysts believe that Onpattro will have a superior competitive profile to Vyndaqel in hATTR-FAP, as its competitor showed only modest efficacy in delaying peripheral neurologic impairment in hATTR-FAP, based on results from a trial (Fx-005) and an open-label, 12-month extension study (Fx-006). Notably, it did not reverse disease progression, as was seen with Onpattro in the Apollo Phase III study in a similar patient group.
Alnylam is also planning for a regulatory submission for Onpattro in Japan in September, followed by additional filings in other key countries by the year end.
Alnylam also expects to report the outcome of an interim analysis of the Phase III Envision study of givosiran in acute hepatic porphyrias by the end of September, which if positive, may allow for a filing for accelerated approval. Full study results are expected in early 2019.