Just in front of its option deadline, Celgene Corporation (NASDAQ:CELG) has re-upped on an existing research and discovery collaboration with Epizyme Inc (NASDAQ:EPZM), a developer of targeted cancer therapies.

Celgene already has ex-US rights to Epizyme’s pinometostat (EPZ-5676), a HMT inhibitor targeting DOT1L that’s currently in phase I development for acute leukemia with alterations in the MLL gene (MLL-r), but the original agreement called for epizyme to continue researching new targets for the collaboration. Celgene and Epizyme inked the partnership in April of 2012, and Celgene’s option to continue the discovery program would have expired this month. The amended agreement, for $10 million up front and up to $610 million in future milestone payments, extends the collaboration by three years and gives Celgene the opt-in on three targets prior to beginning clinical studies. Epizyme will be responsible for leading and funding development for each target candidate through phase I, with Celgene paying an additional fee after. Epizyme will receive a low double-digit percentage royalty on worldwide net sales for two of the product candidates, and on ex-US sales for the third product.

Epizyme’s lead program tazemetostat (EPZ-6438) is a small molecule inhibitor of EZH2 currently being tested in a 150-patient non-Hodgkin’s Lymphoma trial, with data due next year. Tazemetostat demonstrated a 60% response rate in an ongoing phase I study.

On the ratings front, Celgene has been the subject of a number of recent research reports. In a report issued on June 30, J.P. Morgan analyst Cory Kasimov reiterated a Hold rating on CELG, with a price target of $126, which implies an upside of 7.3% from current levels. Separately, on the same day, RBC’s Michael Yee maintained a Buy rating on the stock and has a price target of $135.

According to TipRanks.com, which ranks over 7,500 financial analysts and bloggers to gauge the performance of their past recommendations, Cory Kasimov and Michael Yee have a total average return of 11% and 11.1% respectively. Kasimov has a success rate of 55.8% and is ranked #329 out of 3694 analysts, while Yee has a success rate of 69.4% and is ranked #254.

The street is mostly Bullish on CELG stock. Out of 8 analysts who cover the stock, 6 suggest a Buy rating and 2 recommend to Hold the stock. The 12-month average price target assigned to the stock is $146.00, which implies an upside of 24.3% from current levels.