A Safety Study of MM-121 With Cetuximab and Irinotecan in Patients With Advanced Cancers

To establish the safety of escalating doses of MM-121 in combination with cetuximab or in combination with cetuximab and irinotecan 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.

Time frame: From date of first dose to 30 days after termination, the longest 48.1 weeks

Population: Patients participating in dose escalation

Using a 3+3 dose escalation model, the maximum tolerated dose of each combination was determined by assessing dose-limiting toxicities in each cohort. RP2D = one dose lever lower than the MTD Part 1: Cohort 1: MM-121: 12 mg/kg MM-121 QW + Cetuximab: 400 mg/m2 loading dose/200 mg/m2 (400/200) QW maintenance Cohort 2a: MM-121: 20 mg/kg IV QW + Cetuximab: 400 / 200 mg/m2 maintenance IV QW Cohort 2b: MM-121: 12 mg/kg IV QW + Cetuximab: 400 /250 mg/m2 maintenance IV QW Cohort 3a: MM-121: 40 mg/kg loading dose followed by 20 mg/kg IV QW (40/20) + Cetuximab: 400 / 200 mg/m2 maintenance IV QW Cohort 3b: MM-121 20 mg/kg IV QW + Cetuximab: 400 /250 mg/m2 maintenance IV QW Cohort 4: MM-121: 40/20 mg/kg IV QW + Cetuximab: 400 / 250 mg/m2 maintenance IV QW Part 2: Cohort 1: MM-121: 20 mg/kg IV QW + Cetuximab: 400/200 mg/m2 maintenance IV QW + Irinotecan: 180 mg/m2 IV Q2W Cohort 2: MM-121: 40 / 20 mg/kg IV QW + Cetuximab: 400/250 mg/m2 maintenance IV QW + Irinotecan: 180 mg/m2

Time frame: From date of first dose to 30 days after termination, the longest 48.1 weeks

Population: Number of patients participating in dose-escalation portion (excluding expansion cohort patients who were not evaluated for DLTs and thus not included in determining MTD/RP2D) NOTE: MTD of MM-121 provided in separate endpoint entry

Using a 3+3 dose escalation model, the maximum tolerated dose of each combination was determined by assessing dose-limiting toxicities in each cohort. RP2D = one dose lever lower than the MTD Part 1: Cohort 1: MM-121: 12 mg/kg MM-121 QW + Cetuximab: 400 mg/m2 loading dose/200 mg/m2 (400/200) QW maintenance Cohort 2a: MM-121: 20 mg/kg IV QW + Cetuximab: 400 / 200 mg/m2 maintenance IV QW Cohort 2b: MM-121: 12 mg/kg IV QW + Cetuximab: 400 /250 mg/m2 maintenance IV QW Cohort 3a: MM-121: 40 mg/kg loading dose followed by 20 mg/kg IV QW (40/20) + Cetuximab: 400 / 200 mg/m2 maintenance IV QW Cohort 3b: MM-121 20 mg/kg IV QW + Cetuximab: 400 /250 mg/m2 maintenance IV QW Cohort 4: MM-121: 40/20 mg/kg IV QW + Cetuximab: 400 / 250 mg/m2 maintenance IV QW Part 2: Cohort 1: MM-121: 20 mg/kg IV QW + Cetuximab: 400/200 mg/m2 maintenance IV QW + Irinotecan: 180 mg/m2 IV Q2W Cohort 2: MM-121: 40 / 20 mg/kg IV QW + Cetuximab: 400/250 mg/m2 maintenance IV QW + Irinotecan: 180 mg/m2

Time frame: From date of first dose to 30 days after termination, the longest 48.1 weeks

Population: Number of patients participating in dose-escalation portion (excluding expansion cohort patients who were not evaluated for DLTs) MTD of cetuximab and irinotecan for the combination(s) are presented in a separate endpoint entry

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

Time frame: Samples were collected for all patients pre-dose on all cycles for duration of treatment, the longest of which was 48.1 weeks, and a collection was made post-infusion in any case of infusion reaction

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.

Time frame: Patients were assessed for objective response from time of first dose through treatment termination, the longest treatment duration being 48.1 weeks

Pharmacokinetic (PK) evaluation was performed on plasma samples obtained weekly for the first six weeks 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)

Time frame: Collections taken for all patients at Cycle 1, Week 1 at pre-infusion, at the end of the infusion, and 2.5, 4, 6 and 24 hours after starting the infusion of MM-121

Population: Data presented by dose level of MM-121, regardless of the cohort (i.e. 15 patients in Part 1 were administered the 40/20 dose level of MM-121: 3 in cohort 3b, 4 in cohort 4, and 8 in the Part 1 expansion)

Pharmacokinetic (PK) evaluation was performed on plasma samples obtained weekly for the first six weeks 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) and per study part (Part 1 or Part 2)

Time frame: Collections taken for all patients at Cycle 1, Week 1 at pre-infusion, at the end of the infusion, and 2.5, 4, 6 and 24 hours after starting the infusion of MM-121