Over 70 percent of patients in the first-line subgroup responded to amivantamab plus chemotherapy with most responses lasting beyond 16 months

Notable responses were also seen in patients with liver metastases, who often face poorer outcomes with this disease

Johnson & Johnson announced new longer follow-up results from the investigational Phase 1b/2 OrigAMI-1 study evaluating amivantamab-vmjw, a bispecific antibody targeting epidermal growth factor receptor (EGFR) and MET, in combination with FOLFOX or FOLFIRI chemotherapy in patients with RAS/BRAF wild-type metastatic colorectal cancer. The encouraging anti-tumor activity, durable responses, and low rates of treatment-related discontinuations observed in this study support further investigation in ongoing Phase 3 studies in first- and second-line colorectal cancer. 

"These results show the potential of amivantamab combined with chemotherapy to deliver meaningful and durable benefit for people with advanced colorectal cancer, including for those with liver metastases who have historically faced poorer outcomes," said Dr. Filippo Pietrantonio,* M.D., Head of the Gastrointestinal Oncology Unit, IRCCS Foundation, National Cancer Institute, Milan, Italy. "Seeing patients maintain responses for extended periods, some beyond two years, is a powerful sign of progress in a disease where sustained efficacy has been hard to achieve and speaks to the promise of this treatment approach."

Colorectal cancer is the third most commonly diagnosed cancer worldwide, and a leading cause of cancer-related death. While traditionally seen in older adults, incidence is rising in people under 50. More than half of patients will eventually develop metastatic disease, with liver involvement in roughly 70 percent of cases. In this setting, resistance to current first-line therapies often develops early, shortening the time patients can benefit.⁴ For those with RAS/BRAF wild-type metastatic colorectal cancer with disease progression, second-line options remain limited, with historical response rates of 32 to 36 percent and median progression-free survival (PFS) of 5.4 to 6.4 months using EGFR inhibitors and chemotherapy.^5,6,7,8,9,10 Research has shown that MET alterations are a frequent cause of resistance to EGFR-inhibition, highlighting a need for new approaches that target both pathways simultaneously.¹¹

Detailed Study Results

Cohorts D and E of the Phase 1b/2 OrigAMI-1 study evaluated intravenous amivantamab as monotherapy or in combination with either FOLFOX or FOLFIRI chemotherapy in patients with RAS/BRAF wild-type metastatic colorectal cancer. Patients were confirmed to be negative for KRAS, NRAS, BRAF and EGFR mutations, and did not have HER2 amplification. They could have received one prior line of systemic therapy in the metastatic setting, and prior treatment with an EGFR inhibitor was not permitted. The primary endpoint was safety, and secondary endpoints included overall response rate (ORR), duration of response (DOR), clinical benefit rate, and PFS. Overall survival was assessed as an exploratory endpoint.¹

At a median follow-up of 16 months (range, 1.2-29.5), amivantamab plus FOLFOX (n=20) or FOLFIRI (n=23) achieved a confirmed ORR of 51 percent (95 percent confidence interval [CI], 36-67) across the study, with responses observed early and a median time to first response of 8.3 weeks (range, 7.3-20.3), along with a median DOR of 9.3 months (95 percent CI, 5.8-14.7). Median PFS was 9.2 months (95 percent CI, 5.4-12.9), and median overall survival was not estimable (NE) (95 percent CI, 16.2-NE). In the first-line subgroup, ORR was 73 percent (95 percent CI, 53-86), with median DOR not yet reached at the time of data cutoff (95 percent CI, 7.3-NE). Among 11 patients treated in the first-line subgroup, four were able to proceed to curative intent surgery. In the second-line subgroup (n=32), ORR was 44 percent (95 percent CI, 26-62) and median DOR was 7.4 months (95 percent CI, 5.4-14.5). More than one-third of patients treated in the second-line setting remained on therapy for over one year, and three patients have stayed on amivantamab treatment for more than two years. In patients with liver metastases (n=30), the study showed notable activity, with an ORR of 57 percent (95 percent CI, 37-75) and a median PFS of 11.3 months (95 percent CI, 5.9-16.4).¹

The safety profile remained consistent with prior reports of amivantamab plus chemotherapy in colorectal cancer and with the known safety profiles of the individual agents. Treatment-emergent adverse events were primarily related to EGFR and MET inhibition and known chemotherapy-associated effects. Four patients (9 percent) discontinued therapy due to treatment-related adverse events. The most common Grade 3 or higher event was neutropenia, and no new safety signals were observed.¹

"Treatment for metastatic colorectal cancer has remained largely unchanged for many years, underscoring the need for new strategies," said Kiran Patel, M.D., Vice President, Global Head, Solid Tumor Clinical Development and Companion Diagnostics, Johnson & Johnson Innovative Medicine. "We are drawing on our scientific leadership in EGFR-driven lung cancer to evaluate the potential of amivantamab, and its dual-targeting of EGFR and MET, in colorectal cancer and other solid tumors driven by these pathways."  

Pivotal Phase 3 studies, including the global, randomized OrigAMI-2 and OrigAMI-3 studies evaluating subcutaneous amivantamab with FOLFOX and FOLFIRI, are underway to further evaluate the potential of amivantamab-based regimens in both first- and second-line colorectal cancer.a