Pfizer's Vyndaqel franchise, buoyed by diagnoses, is poised for 'a decisive beat': analyst

With ATTR-CM diagnosis rate on the rise, Pfizer's Vyndaqel franchise could easily beat the Street's 2019 sales expectations, SVB Leerink says. (Pfizer)

Pfizer’s much-anticipated Vyndaqel franchise has been on a road paved with blockbuster hopes since its FDA nod in May. Now, one group of analysts says the drug’s early uptake has been faster than expected.

After examining electronic medical records, SVB Leerink analyst Mani Foroohar estimates Vyndaqel could garner $157 million in 2019 U.S. sales, well above the Street’s full-year consensus of $84 million, in what could be “a decisive beat”.

In fact, SVB Leerink suggests Vyndaqel prescriptions have jumped 62% from the second quarter to the third, with minimal discontinuations, Foroohar said in a Friday note to clients. Its weekly total scripts have grown to 142 in Q3 from 31 in Q2, Bloomberg’s Symphony data cited by the analyst show.

Pfizer has indicated that the success of Vyndaqel—which shares its active ingredient, tafamidis, with Vyndamax, approved at the same time—depends on driving up diagnosis rates of ATTR cardiomyopathy, the indication Vyndaqel is currently approved in. Both the scripts data and physician feedback suggest that is indeed the trend; ATTR amyloidosis diagnoses increased 16%, accounting for around 1,600 additional new patients, in Q3 versus Q2, according to Foroohar.

Before Vyndaqel arrived, the lack of treatments for ATTR-CM and the use of invasive heart biopsies had held back diagnosis. But a recent SVB Leerink survey of 55 U.S. TTR-treating physicians in its network suggested the “availability of tafamidis is a catalyst for increased non-invasive ATTR-CM screening,” thanks at least in part to advocacy by Pfizer, Foroohar said.

In Q2, Pfizer reported Vyndaqel sales of $8 million. Around 2,100 patients, including 1,400 on commercial plans and another 700 on compassionate use, had been prescribed the drug, even though only 525 actually got the medicine. For the coming quarters, Pfizer’s revenue could come from bringing in new patients as well as transitioning those from clinical trials.

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Assuming a 2.4% weekly growth in scripts, Foroohar landed at 4,700 patients who will have been prescribed Vyndaqel by year's end and a 2019 U.S. haul of $159 million.

Moving forward, Pfizer also needs to beat rival drugs—Alnylam Pharmaceuticals’ Onpattro and Ionis’ Tegsedi—which are both approved to treat the polyneuropathy form of hereditary ATTR. Vyndaqel’s ATTR-PN application was rejected by the FDA in 2012, but Pfizer has said it's working with the agency on another try. The med has already been approved for that use in 40 countries, including in Europe.

Meanwhile, Alnylam’s and Ionis’ antisense oligonucleotide inhibitors are also trying to get into cardiomyopathy, setting up a head-to-head battle in that indication, too.

According to results from SVB Leerink’s physician survey published in September, Vyndaqel is the clear preferred treatment in both ATTR-CM and mixed phenotype patients. As for ATTR-PN, the Pfizer drug is a close second, with its 27% estimated peak penetration trailing Onpattro’s 33%.