Epizyme's first-in-class Tazverik launch on track to top Gilead's Zydelig: analyst

up arrow, sales growth, chart
Epizyme's Tazverik "should be a better launch than Zydelig," Jefferies analyst Michael Yee wrote to clients. (oatawa/Getty Images via Newscred)

New commercial player Epizyme is seeing encouraging early signs with its freshly approved cancer med Tazverik. And thanks to an earlier-than-expected FDA decision date for a potential label expansion, the drug’s on track to top the launch of Gilead Sciences’ rival drug Zydelig, one team of analysts figures.

In January, Tazverik became the first drug specifically approved to treat patients with epithelioid sarcoma (ES). It could see rapid adoption across all lines of treatment and an increase in the number of eligible patients as a result of physician education, Epizyme CEO Rob Bazemore said on a conference call Monday.

The drug—the first in the EZH2 inhibitor class—was made available within 10 days of approval and the National Comprehensive Cancer Network recently added it to its treatment guidelines for soft tissue sarcoma, “showing the validation from physicians,” SVB Leerink’s Andrew Berens said in a Monday note to clients.

Epizyme’s aiming for a wider market than the rare ES disease, though. Its recent filing in third-line follicular lymphoma (FL) was accepted by the FDA as a supplemental new drug application—rather than the more complicated NDA the company had intended—and was granted priority review. The designation moved the decision deadline to June 18, up from August, as previously expected.

And the demand is there. There are already patients with FL—as well as other INI1-negative tumors—calling in for Tazverik, according to Bazemore.

Jefferies analyst Michael Yee figures some off-label cases are already being prescribed the drug by physicians who are aware of it ahead of approval. To that end, Yee’s team argues the Street’s Tazverik sales consensus for this year—$35 million—is “beatable,” given that most analysts model for ES only.

“[T]his should be a better launch than Zydelig, in our view,” Yee wrote in his note. The Gilead drug was approved mid-2014 to treat chronic lymphocytic leukemia, FL and small lymphocytic lymphoma. In the first three quarters of commercialization, the PI3K inhibitor generated sales of $6 million, $17 million and $26 million.

RELATED: Epizyme scores FDA nod for rare cancer med Tazverik but prices it for a future indication: analyst

Looking for a seamless launch of Tazverik in FL upon approval, Epizyme has already started building up its commercial team and nearly completed market research to understand the treatment landscape, Bazemore said.

To hear Bazemore tell it, the small ES market—with just about 300 U.S. patients eligible for Tazverik—is more of a testing ground for Epizyme to gain commercial experience and to identify hiccups to patient access so that everything’s streamlined when the FL nod arrives.

“The field-based structure of around 19 people, we're going to ultimately be pivoting this year to get ready for the FL market opportunity given the fact that we'll be spending more time in the community practice setting,” Epizyme Chief Strategy & Business Officer Matt Ros said on the call. The company will add 47 sales reps to the team in preparation for the anticipated market expansion, he added.

Ultimately, Epizyme hopes to push Tazverik upward to earlier lines of therapy and reach all FL patients. It’s designed a confirmatory trial to compare Tazverik plus Celgene's Revlimid and Roche's Rituxan (R2) with the R2 regimen alone in the second-line setting. In first-line FL, the company plans to combine Tazverik with the R-CHOP regimen. Zydelig never reached the front-line market after clinical trials turned up serious side effects.