To determine whether MM-121 + paclitaxel was more effective than paclitaxel alone in prolonging progression-free survival in advanced ovarian cancers resistant or refractory to platinum agents. PFS was a time to event measure, and progression of disease is defined using Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.1), "as a 20% increase in the sum of the longest diameter of target lesions, or a measurable increase in a non-target lesion, or the appearance of new lesions". Progression free survival was defined as the number of months from the date of randomization to the date of death or progression. If neither death nor progression was observed during the study, PFS data was censored at the last non-progressive disease valid tumor assessment unless the patient was discontinued due to symptomatic deterioration. If this occurred, the patient was counted as having progressive disease (PD).

To determine whether MM-121 + paclitaxel is more effective than paclitaxel alone in prolonging overall survival. This was a time-to-event analysis of time from first dose to date of death.

Fresh tumor samples were obtained from patients prior to enrollment and formalin-fixed for analysis. Samples were analyzed using RNA-ISH for the expression of the biomarker, heregulin. Progression-free survival was assessed using RECIST v 1.1 to determine whether patients whose tumors express HRG have a lower PFS than those whose tumors do not express HRG, and to assess whether the addition of MM-121 to Paclitaxel can increase PFS in HRG-high patients.

Patients with available tissue for RNA-ISH analysis