What happened

Shares of Epizyme (NASDAQ:EPZM) rallied sharply higher following data showing its lead drug candidate, tazemetost, delivered solid response rates in follicular lymphoma. Shares finished trading today up 17.4%.

So what

Tazemetostat won fast-track status this spring for use in relapsed or refractory follicular lymphoma, either with wild-type EZH2 or with EZH2 activating mutations.

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IMAGE SOURCE: GETTY IMAGES.

At the International Conference on Malignant Lymphoma (ICML), Epizyme rolled out data for tazemetostat in this indication that impressed. Specifically, in patients with the EZH2 mutation, the drug delivered an objective response rate of 92%. Of the patients participating in the trial, the median number of previous treatments was four. Overall, 85% of patients had a partial response, 8% had a complete response, and the remaining patients had stable disease.

In wild-type EZH2 mutation follicular lymphoma patients, the objective response rate (ORR) was 26%, but 43% had stable disease.

Epizyme also reported tazemetostat data for its use in diffuse large B-cell lymphoma (DLBCL), the most common form of non-Hodgkin lymphoma. The ORR for patients who have had a median three prior treatments was 29% for EZH2 mutation patients and 15% for wild-type EZH2 mutation patients. 

Now what

There are 25,000 new cases of follicular lymphoma diagnosed in the U.S. annually, and up to 20% of those patients have the EZH2 mutation. Currently, patients are treated with chemotherapy plus Rituxan. However, most patients end up relapsing, and treatment options when the disease returns are limited. Therefore, the findings in these indications are particularly intriguing.

The findings in DLBCL weren't as strong, but there's still a need for new treatments for heavily pre-treated patients, so there may be an opportunity to carve out a niche in that patient population, too.

Epizyme expects to sit down with the FDA to discuss data and the potential pathways to approval before the end of 2017. It's unclear what additional trials may need to happen to get this drug across the finish line, but what's important to investors is that the data appears good enough to continue its development, and potentially get commercialized someday.

Todd Campbell has no position in any stocks mentioned. His clients may have positions in the companies mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.