Safety and tolerability data presented in detail in the adverse events and serious adverse events section of the results posting

Using a 3+3 dose escalation model, the maximum tolerated dose of each therapy combination was determined by assessing dose-limiting toxicities in each cohort. If 3 patients were treated and passed the observation window, escalation to the next cohort was initiated. If a DLT was reported, 3-4 additional patients were enrolled and observed. If a DLT was observed in expanded cohort, this dose was considered to be the maximum tolerated dose. The maximum tolerated dose was defined at the cohort in which two dose-limiting toxicities were observed, or as the highest target dose tested in the absence of DLTs. The determined MTD was considered the Recommended Phase 2 Dose.

Dose Levels (3 week cycles) MM-121 doses tested: 20 mg/kg IV one-time loading dose then 12 mg/kg IV QW (20/12 mg/kg); 40/20 mg/kg Gemcitabine doses tested: 1000 mg/m2 Day 1 and 8 Pemetrexed doses tested: 500 mg/m2 Day 1 Carboplatin doses tested: 5 or 6 AUC Day 1 Cabazitaxel doses tested: 20 or 25 mg/m2 Day 1 of 3

Note: data provided below is for MM-121 doses only for the combination. Combination therapy MTDs are provided in separate endpoint measures.

Using a 3+3 dose escalation model, the maximum tolerated dose of each therapy combination was determined by assessing dose-limiting toxicities in each cohort. If 3 patients were treated and passed the observation window, escalation to the next cohort was initiated. If a DLT was reported, 3-4 additional patients were enrolled and observed. If a DLT was observed in expanded cohort, this dose was considered to be the maximum tolerated dose. The maximum tolerated dose was defined at the cohort in which two dose-limiting toxicities were observed, or as the highest target dose tested in the absence of DLTs. The determined MTD was considered the Recommended Phase 2 Dose.

Dose Levels (3 week cycles) MM-121 doses tested: 20 mg/kg IV one-time loading dose then 12 mg/kg IV QW (20/12 mg/kg); 40/20 mg/kg Gemcitabine doses tested: 1000 mg/m2 Day 1 and 8

NOTE: Maximum tolerated dose is for the combination of gemcitabine and MM-121. MTD of MM-121 is provided in separate endpoint.

Maximum Tolerated Dose reported in Target AUC, as calculated by the Calvert Formula

Using a 3+3 dose escalation model, the maximum tolerated dose of each therapy combination was determined by assessing dose-limiting toxicities in each cohort. If 3 patients were treated and passed the observation window, escalation to the next cohort was initiated. If a DLT was reported, 3-4 additional patients were enrolled and observed. If a DLT was observed in expanded cohort, this dose was considered to be the maximum tolerated dose. The maximum tolerated dose was defined at the cohort in which two dose-limiting toxicities were observed, or as the highest target dose tested in the absence of DLTs. The determined MTD was considered the Recommended Phase 2 Dose.

Dose Levels (3 week cycles) MM-121 doses tested: 20 mg/kg IV one-time loading dose then 12 mg/kg IV QW (20/12 mg/kg); 40/20 mg/kg Carboplatin doses tested: 5 or 6 AUC Day 1

Using a 3+3 dose escalation model, the maximum tolerated dose of each therapy combination was determined by assessing dose-limiting toxicities in each cohort. If 3 patients were treated and passed the observation window, escalation to the next cohort was initiated. If a DLT was reported, 3-4 additional patients were enrolled and observed. If a DLT was observed in expanded cohort, this dose was considered to be the maximum tolerated dose. The maximum tolerated dose was defined at the cohort in which two dose-limiting toxicities were observed, or as the highest target dose tested in the absence of DLTs. The determined MTD was considered the Recommended Phase 2 Dose.

Dose Levels (3 week cycles) MM-121 doses tested: 20 mg/kg IV one-time loading dose then 12 mg/kg IV QW (20/12 mg/kg); 40/20 mg/kg Pemetrexed doses tested: 500 mg/m2 Day 1

Using a 3+3 dose escalation model, the maximum tolerated dose of each therapy combination was determined by assessing dose-limiting toxicities in each cohort. If 3 patients were treated and passed the observation window, escalation to the next cohort was initiated. If a DLT was reported, 3-4 additional patients were enrolled and observed. If a DLT was observed in expanded cohort, this dose was considered to be the maximum tolerated dose. The maximum tolerated dose was defined at the cohort in which two dose-limiting toxicities were observed, or as the highest target dose tested in the absence of DLTs. The determined MTD was considered the Recommended Phase 2 Dose.

Dose Levels (3 week cycles) MM-121 doses tested: 20 mg/kg IV one-time loading dose then 12 mg/kg IV QW (20/12 mg/kg); 40/20 mg/kg Cabazitaxel doses tested: 20 or 25 mg/m2 Day 1 of 3

To establish the safety of escalating doses of MM-121 administered in combination with multiple anti-cancer therapies in order to determine the recommended phase 2 dose. Dose-escalation conducted using standard 3+3 model to determine maximum tolerated dose. Reports of Dose-Limiting Toxicities (DLTs) were assessed to determine the MTD to be used for the expansion cohort. DLTs were not measured in the Expansion Cohort.

To determine the number of patients reporting an objective response using RECIST v 1.1 where a Partial Response (PR) is defined as >20% decrease in tumor burden from baseline and a Complete Response (CR) is defined as complete disappearance from tumor burden from baseline. Objective Response is presented as the total # patients with PR or CR.

Pharmacokinetic (PK) evaluation was performed on plasma samples obtained weekly for the first cycle of the study and then on day 1 of each additional cycle to assess pre-treatment trough concentrations of MM-121. Non-compartmental analysis (NCA) was performed to calculate standard PK parameters, including the maximum observed concentration (Cmax). Serum levels of MM-121 were measured at a central lab using an enzyme-linked immunosorbent assay (ELISA). Data is presented per dose level of MM-121 (12 mg/kg, 20 mg/kg, or 40/20 mg/kg).

Pharmacokinetic (PK) evaluation was performed on plasma samples obtained weekly for the first cycle of the study and then on day 1 of each additional cycle to assess pre-treatment trough concentrations of MM-121. Non-compartmental analysis (NCA) was performed to calculate standard PK parameters, including the AUClast. Serum levels of MM-121 were measured at a central lab using an enzyme-linked immunosorbent assay (ELISA). Data is presented per dose level of MM-121 (12 mg/kg, 20 mg/kg, or 40/20 mg/kg) and per study part (Part 1 or Part 2).

Samples were collected to determine the presence of an immunologic reaction to MM-121 (i.e. human anti-human antibodies).