- Epizyme has taken another step forward on the path to its first commercialized drug, announcing Thursday submission of an application to the Food and Drug Administration for accelerated approval of its most advanced experimental cancer drug.
- That application is for use of the drug, called tazemetostat, to treat epithelioid sarcoma, a rare and aggressive type of tissue cancer. Epizyme plans to also submit the therapy for approval in follicular lymphoma by year's end.
- Investors appeared content with the regulatory progress, as shares in the Cambridge, Massachusetts-based company rose by more than 5% Thursday morning.
While Epizyme aims to win approval first in epithelioid sarcoma, the biotech's plans are to position tazemetostat in other cancer types and earlier treatment lines over time.
That expansion will be important for the drug's commercial potential. Wall Street analysts generally forecast peak sales in epithelioid sarcoma at no more than $100 million.
If approved, tazemetostat would be the first treatment specifically cleared for the cancer type, which is typically diagnosed in young adults and has a median overall survival of about 2.5 years from diagnosis, according to the biotech.
Epizyme's application is largely based on an uncontrolled, open-label Phase 2 study. That trial enrolled 24 treatment-naive patients and 38 relapsed or refractory patients with epithelioid sarcoma, of whom nine experienced a response to treatment, according to a recently published abstract. Median overall survival was just over 1.5 years across the entire group of 62. Most patients received prior therapy, with some having received as many as 9 lines of treatment.
"We are encouraged by this data as it continued to show tazemetostat's durable efficacy and favorable safety," wrote Yaron Werber, a Cowen & Co. analyst covering Epizyme.
But the question remains whether a 15% response rate will be enough to persuade the FDA, particularly amid criticism of the agency's use of speedy OKs for cancer drugs. Just this week, new research found just 19 of 93 cancer drug approvals cleared via accelerated review were supported by follow-up studies demonstrating an improvement in patient survival.
The findings "raise several doubts about the success of the accelerated approval process," a group of University of Pennsylvania researchers wrote in JAMA Internal Medicine.
Epizyme will present updated data from that trial at the upcoming annual meeting of the American Society of Clinical Oncology. Pending FDA approval of the initial application, the biotech anticipates starting a randomized, controlled trial in the second half of 2019 to pursue a full regulatory OK.
The forthcoming submission for follicular lymphoma, meanwhile, will be particularly important, as that cancer type affects more patients than epithelioid sarcoma. Updated data from a pivotal Phase 2 study, expected next month, will be a central component of that application.
Epizyme's strategy is to move beyond tazemetostat by building a pipeline with at least three new product candidates, CEO Robert Bazemore said on recent earnings call.
In addition to developmental partnerships with GlaxoSmithKline and Boehringer Ingelheim, the biotech has an experimental treatment for sickle cell disease expected to begin Phase 1 testing later this year.
Jefferies analyst Michael Yee has also recently speculated Epizyme would be a good M&A fit for several big pharmas, similar to recent oncology deals for Loxo Oncology and Tesaro. Yee estimated a takeout price of $2 billion would be necessary to secure a deal.