MM-121: Phase II data

Merrimack disclosed on a conference call to discuss its 2Q13 earnings that it will stop enrollment in Group B of a single-arm, open-label, international Phase II trial after a pre-specified interim analysis by a DSMB showed that MM-121 plus Tarceva erlotinib missed undisclosed criteria for continuing enrollment and would not meet the primary endpoint of improving PFS. Group B enrolled 43 of the planned 70 NSCLC patients with a known EGFR-activating mutation who have received no prior EGFR therapy in the metastatic setting. Data from the 43 patients, who will continue on treatment, are expected in 2014.

Additionally, Merrimack said interim data from patients in Group A of the trial showed that MM-121 plus Tarceva met the undisclosed pre-specified criteria for continuing to full enrollment of 120 NSCLC patients with EGFR wild-type tumors who have recurring or progressive disease following >=1 chemotherapy regimen in the metastatic setting and have received no prior EGFR therapy. However, the DSMB said interim data from the overall population in Group A showed that MM-121 would not meet the primary endpoint of improving PFS. Merrimack will continue Group A to full enrollment based on "expectations of the potential for subgroup benefit." The company expects to report final data from Group A this year. Merrimack said the primary endpoint of Group A and B is PFS, but with different thresholds. ...