Epizyme picks up FDA orphan nod for lead cancer drug as going public pays off

Epizyme ($EPZM) has secured an unsurprising yet important orphan designation from the FDA for its lead candidate EPZ-5676 against a rare subset of blood cancers, another in a series of intentional moves by the company to build a business around a new class of targeted treatments.

The drug is in a Phase I clinical trial that began in September 2012. Epizyme's shares rose nearly 1% this morning to $31.44 per share, which is more than double the IPO price of $15 per share set on May 31.

Licensed to Celgene ($CELG) for markets outside the U.S., EPZ-5676 is an inhibitor of an enzyme known as DOT1L that drives misfit gene expression in mixed lineage leukemia (MLL), a subset of blood cancers associated with poor outcomes for adult and pediatric patients alike. Epizyme, which highlighted the drug in its stellar IPO campaign, has moved into a dose-escalation phase of its initial clinical trial of the compound and plans to begin an expansion phase that would focus exclusively on MLL patients later this year. 

The new orphan tag from U.S. regulators gives the company a set of perks such as tax credits, grants, discounted filing fees and potentially 7 years of market exclusivity. Epizyme says that MLL cases afflict about 4,900 patients in major pharma markets, well below the FDA's limit of up to 200,000 patients for qualifying for orphan status.

Epizyme CEO Robert Gould

Orphan designations say very little about the FDA's thinking about the potential of a treatment to benefit patients, unlike programs such as "Breakthrough Therapy" status where regulators weight early clinical trial evidence before awarding an expedited path for development and review. To gain the orphan designation, however, Epizyme (a 2011 Fierce 15 company) provided the agency with epidemiology information and promising preclinical data from tests of the compound in human cells with MLL and animal models of the disease, Robert Gould, Epizyme's CEO, told FierceBiotech.

"Orphan drug designation is consistent with our strategy of focusing on these genetically defined cancers in patients and making a personalized therapeutic," Gould said. "As you define these patient populations, many of them are going to fall below the 200,000-patient cap for orphan designation."

Epizyme has made another small step in a series of seemingly deft maneuvers to become one of the hottest young cancer drug developers in the industry. As Xconomy noted in an interview with top executives, Epizyme has carefully plotted its moves leading up to its highly successful IPO in May, including the terms of its major alliance with Celgene last year that provided a handsome $90 million upfront payment and allowed the company to keep U.S. rights on EPZ-5676.

Gould declined to comment on the likelihood of seeking breakthrough status for the compound because his company hasn't yet obtained the early clinical evidence required to seek the designation. Yet his company was clear in its S-1 that it's seeking rapid development of its compounds, and count on the company to file an app for breakthrough status if its Phase I study of EPZ-5676 produces the desired results in cancer patients.

- here's the release
- check out Xconomy's interview

Special Report: Epizyme - 2011 Fierce 15