A phase 1b/2, open-label study of amivantamab monotherapy or in combination with standard-of-care chemotherapy in participants with advanced or metastatic colorectal cancer.

TPS279 Background: Amivantamab, a fully human EGFR and MET bispecific antibody, has shown clinical activity against tumors with primary activating EGFR mutations, EGFR resistance mutations, or MET pathway activation. Amivantamab has demonstrated activity in both EGFR- and MET-driven non-small cell lung cancer, with preclinical evidence demonstrating its ability to recruit immune effector cells. While two anti-EGFR antibodies are incorporated as part of the standard of care (SoC) for metastatic colorectal cancer (mCRC) patients, MET is highly expressed or amplified in subsets of mCRC and additionally plays a role in mediating resistance to anti-EGFR therapies; therefore, amivantamab may provide benefit in this setting. Methods: This open-label, multicenter, global Ph1b/2 study will assess the safety and anti-tumor activity of amivantamab as a monotherapy and characterize the safety and tolerability of amivantamab in addition to SoC chemotherapy in KRAS, NRAS, BRAF, and EGFR ectodomain wild type participants with advanced or metastatic CRC. The Ph2 amivantamab monotherapy Cohorts A and B will assess the anti-tumor activity in participants with left-sided CRC who have progressed on or after SoC fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy and an anti-VEGF treatment, without (Cohort A) or with (Cohort B) prior exposure to anti-EGFR treatment. The Ph2 amivantamab monotherapy Cohort C will assess the antitumor activity in participants with right-sided CRC who have progressed on or after SoC fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy and an anti-VEGF treatment, with or without an anti-EGFR treatment. The Ph1b dose confirmation cohorts (Ph1b-D and Ph1b-E) will assess the safety and confirm the recommended Ph2 combination dose (RP2CD) of amivantamab in addition to SoC chemotherapy regimens (mFOLFOX6 or FOLFIRI). Upon confirmation of the RP2CD, the Ph2 Cohorts D and E, which are distinct cohorts from Ph1b-D or Ph1b-E, will further characterize the safety, tolerability, and preliminary anti-tumor activity of amivantamab in addition to SoC mFOLFOX6 or FOLFIRI in mCRC patients who have progressed after front-line therapy. The primary objectives are to assess the anti-tumor activity of amivantamab as a monotherapy and characterize the safety of amivantamab when added to SoC chemotherapy in participants with mCRC (Ph2 cohorts), as well as to assess the RP2CD of amivantamab when added to SoC chemotherapy (Ph1b). The key secondary objectives are to characterize the safety of amivantamab as a monotherapy and to assess the anti-tumor activity of amivantamab when added to SoC chemotherapy in participants with mCRC. This study is currently enrolling (NCT05379595) as of August 2022 in 12 countries, with goal enrollment of 225 participants. Clinical trial information: NCT05379595 .