Trust favourite Alnylam sees shares tank on competitor success
US RNAi therapeutic specialist Alnylam Pharmaceuticals (Nasdaq:ALNY) has seen its shares fall by 22% over the long Easter weekend, principally on news of a surprise positive clinical trial result for a potential competitor to its lead product patisiran, which has been developed initially for hereditary transthyretin-mediated amyloidosis for hATTR.
The large stock price move is important as Alnylam is held by a number of the sector’s specialist investment trusts. It is a top 10 holding for Biotech Growth Trust (BIOG, 4.4% of NAV), a top 15 holding for Swiss-listed BB Biotech (BBB, 3.6% of NAV), as well as the largest single holding (5.8% of NAV) for Baillie Gifford-managed Edinburgh Worldwide Investment Trust (EWI), which has is a broad investment remit with a relatively high exposure to healthcare (c26% of NAV).
The fall in Alnylam’s stock was prompted by an announcement from Pfizer last Thursday of a successful phase III study evaluating its product, Vyndaqel (tafamidis), for transthyretin cardiomyopathy, the heart damage that results from transthyretin amyloidosis. Pfizer’s 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. Pfizer’s ATTR-ACT study included both the hereditary and the wild-type forms of the disease, whereas Alnylam has developed patisiran only the the hereditary ATTR.
However, Alnylam believes that patisiran has a superior competitive profile to tafamidis in patients with hATTR-FAP. The Pfizer drug’s European approval was based on results from a trial (Fx-005) and an open-label, 12-month extension study (Fx-006) that showed only modest efficacy in delaying peripheral neurologic impairment in hATTR-FAP, and did not reverse disease progression, as was seen with patisiran in its APOLLO Phase III study in a similar patient group.
Patisiran is under review in the US and EU for hATTR. The product has US breakthrough therapy status, which provides for accelerated approval timelines, and is on track for approval in mid 2018 (the PDUFA action date is 11 Aug). If approved, patisiran is set to become Alnylam’s first marketed product. And under a recent renegotiation of its long-standing R&D/marketing partnership with Sanofi, Alnylam obtained full global control of patisiran (re-gaining rights outside of North America and Western Europe), in exchange for giving up its territorial marketing rights to another jointly developed product, fitusiran for haemophilia. Patisiran is one of 12 potential blockbusters that could receive their first approval this year and has consensus sales forecast of $1.2bn in 2022, although some analysts expect peak revenue of as much as $8.1bn to reflect use in hATTR-polyneuropathy (PN), hATTR-cardiomyopathy (CM) and mixed hATTR–PN/CM.
Alnylam has been granted a wider orphan drug designation to cover ATTR amyloidosis, expanding a prior designation that was limited to familial amyloidotic polyneuropathy. Orphan drug designation is a scheme that provides various incentives to develop drugs for conditions that affect small numbers of patients.
Meanwhile, the UK-based RNAi company Silence Therapeutics disclosed this morning that it had bought patent infringement proceedings against Alnylam in Portugal relating to patisiran, while at the same time, Alnylam had filed a Declaratory Judgement (DJ) in the U.S. federal district court in Boston, Massachusetts. The action seeks a finding of non-infringement of certain Silence patents, although several recently-issued U.S. patents, such as those identified in Silence’s updates dated 15 August 2017, 11 October 2017, and 18 October 2017, are not named in the lawsuit. More information on the lawsuit can be found on the court’s docket.
Trust favourite Alnylam sees shares tank on competitor success