New survey results look ominous for Ionis Pharmaceuticals, as they suggest one of the company’s drugs will take a back seat to rival therapies from Pfizer and Alnylam Therapeutics in a couple U.S. markets.The survey gathered prescribing information from 55 U.S. doctors who treat an uncommon condition known as hereditary transthyretin-mediated amyloidosis, or hATTR. In the states, Pfizer’s Vyndaqel is approved to treat heart disease brought on by hATTR, whereas Alnylam’s drug Onpattro and Ionis’ Tegsedi are cleared to treat the peripheral nerve damaged caused by the condition.Analysts at SVB Leerink who conducted the survey found that doctors “strongly favor” Onpattro to Tegsedi when treating hATTR polyneuropathy, yet they also expect the Alnylam drug to compete for leading market share with Vyndaqel, provided the latter drug ultimately gains approval in that setting. As for hATTR cardiomyopathy, the doctors anticipate Vyndaqel will hold a “commanding” market share, according to SVB Leerink.
Onpattro outpaces its main rival in net revenue, scoring $38 million in the second quarter versus Tegsedi’s $10 million. While Ionis and Akcea touted a 50% increase in Tegsedi prescriptions during that period, the results from SVB Leerink’s survey suggest that progress could be short lived.
“Last year, physicians lacked a clear preference between the oligo agents, but with the benefit of real-world experience with the drugs, physicians strongly favor patisiran over inotersen across all subpopulations,” analyst Mani Foroohar wrote in a Sept. 10 note to clients.
Alnylam can’t rest easy, however, as physicians anticipate Pfizer’s Vyndaqel (tafamidis) to pose a competitive threat to both Tegsedi and Onpattro in the hATTR neuropathy market.
While only recently available in the U.S., Vyndaqel has been approved in Europe under the brand name Vyndamax since 2011 for the treatment of hATTR neuropathy. From April through June, revenue from the drug totaled $63 million, reflecting a 66% year-over-year increase indicative of its strong launch in the U.S.
There, around 1,400 patients with hATTR cardiomyopathy have been prescribed Vyndaqel, of which about 500 have received it, according to Angela Hwang, Group President of the Pfizer Biopharmaceuticals Group.
Meanwhile, Alnylam recently reported that more than 500 patients are getting commercial Onpattro, with another 300 receiving it through compassionate access.
The physicians surveyed by SVB Leerink have collectively written 303 prescriptions for Pfizer’s Vyndaqel — and about seven in 10 said they expect the number of patients prescribed the drug to increase, with the average responder estimating 53% growth over the next two years.
The doctors predicted Vyndaqel will control about just under half of the ATTR cardiomyopathy market, higher than the 19% pegged for Onpattro and 15% for Tegsedi. In the polyneuropathy market, they expect Vyndaqel to take 33% share and Onpattro to take 27% share at their respective peaks.
