Alnylam reprimanded over Amvuttra promotion after Pfizer complaint to UK watchdog

Alnylam Pharmaceuticals (ALNY) has been reprimanded by the UK's Prescription Medicines Code of Practice Authority after a complaint from Pfizer (PFE), though the industry watchdog softened its harshest criticism on appeal.

The case centered on Alnylam's activities at the European Society of Cardiology's 2024 congress in London, where the company shared information on Amvuttra, its RNAi therapy for hereditary transthyretin amyloidosis. At the time, Amvuttra was approved only for polyneuropathy caused by the condition and was weeks away from being submitted for approval in transthyretin amyloidosis with cardiomyopathy, or ATTR-CM.

Pfizer, which markets the competing ATTR therapy Vyndamax, filed the complaint after failing to resolve concerns directly with Alnylam. It alleged that Alnylam promoted Amvuttra outside the scope of its marketing authorization through booth materials, an evening meeting it organized on ATTR, and two tutorial sessions.

The PMCPA initially found that Alnylam had brought discredit upon the pharmaceutical industry, its most serious sanction. That finding was overturned on appeal. Alnylam successfully argued that one tutorial, covering treatment of polyneuropathy patients with a mixed phenotype, did not constitute off-label promotion, since discussion of cardiac manifestations fell within Amvuttra's licensed indication.

The appeal board reached a different verdict on the evening meeting, however, upholding the original finding that Alnylam had promoted Amvuttra outside its marketing authorization by presenting data on the drug in ATTR-CM before that indication was licensed. The board said proactively sharing data on a licensed product for an unlicensed use was likely to count as promotional, and Alnylam failed to convince it that this instance was an exception.

With one finding upheld and one reversed, the appeal board concluded that the original discredit ruling had been disproportionate, though it maintained that Alnylam had failed to uphold high standards by promoting Amvuttra for an unlicensed indication.

The case exposed sharp tension between the two companies. In its response, Alnylam accused Pfizer of cherry-picking information and taking its conference activities out of context to create a misleading impression, describing Pfizer's allegations as sweeping and unsubstantiated.

The stakes reflect a lucrative market. Alnylam reported Amvuttra sales of $890mn in the first quarter, with US demand from ATTR-CM patients driving growth of 187 percent. Pfizer's Vyndamax franchise generated $1.6bn over the same period. BridgeBio Pharma (BBIO) also markets an approved ATTR-CM treatment, Attruby.