The U.S. Food and Drug Administration (FDA) has approved Amgen’s LUMAKRAS (sotorasib) in combination with Vectibix (panitumumab) for the treatment of adult patients with KRAS G12C-mutated metastatic colorectal cancer (mCRC), who have received prior fluoropyrimidine-, oxaliplatin- and irinotecan-based chemotherapy.
Approval is based on the pivotal Phase 3 CodeBreaK 300 study, which demonstrated that LUMAKRAS plus Vectibix is the first and only targeted treatment combination for chemorefractory KRAS G12C-mutated mCRC to show superior progression-free survival (PFS) compared to the investigated standard-of-care (SOC).
“Colorectal cancer is the third leading cause of cancer-related deaths in the United States, and fewer than one in five people diagnosed with metastatic disease survive beyond five years after diagnosis,” said Jay Bradner, M.D., executive vice president of Research and Development at Amgen.
“LUMAKRAS plus Vectibix offers a targeted, biomarker-driven combination therapy that helps delay disease progression more effectively than the investigated standard of care. This new option validates our combination approach to improve outcomes for patients living with advanced KRAS G12C-mutated metastatic colorectal cancer.”
The CodeBreaK 300 clinical trial compared LUMAKRAS at two different doses (960 mg daily or 240 mg daily) in combination with Vectibix to the investigator’s choice of SOC (trifluridine and tipiracil or regorafenib) in patients with chemorefractory KRAS G12C-mutated mCRC.
Study results demonstrated that LUMAKRAS 960 mg daily plus Vectibix (n=53) showed an improved median PFS of 5.6 months (4.2, 6.3) compared to 2 months (1.9, 3.9) on investigator’s choice of care (n=54), with a hazard ratio (HR) of 0.48 (95% Confidence Interval [CI]: 0.3, 0.78) and a p-value of 0.005. The study demonstrated an improved overall response rate (ORR) of 26% (95% CI: 15, 40) compared to 0% with investigator’s choice (95% CI: 0, 7). The study was not statistically powered for overall survival (OS).
The median overall survival (mOS) for patients treated with LUMAKRAS plus Vectibix was not reached (NR) (8.6, NR), and mOS for patients treated with investigator’s choice was 10.3 months (7, NR), with a HR of 0.7 (95% CI: 0.41, 1.18); the final analysis of OS was not statistically significant. Safety profiles were consistent with those historically observed for LUMAKRAS and Vectibix. The most common adverse reactions (≥20%) are rash (87%), dry skin (28%), diarrhea (28%), stomatitis (26%), fatigue (21%) and musculoskeletal pain (21%). PFS of LUMAKRAS 240 mg daily plus Vectibix (n=53) compared to investigator’s choice was not statistically significant.
The KRAS G12C mutation is present in approximately 3-5% of colorectal cancers as determined by an FDA-approved biomarker test. This emphasizes the important role of comprehensive biomarker testing in mCRC. By detecting an actionable mutation, eligible patients are now able to receive a corresponding targeted therapy that may lead to improved responses.
“In metastatic colorectal cancer, KRAS mutations are historically associated with worse mortality rates and inferior outcomes compared to non-mutated tumors, and standard treatment options have shown minimal benefit,” said Marwan G. Fakih, M.D., primary study investigator and co-director of the Gastrointestinal Cancer Program, City of Hope.
“Designed for dual blockade of KRAS G12C and EGFR pathways, the combination of sotorasib plus panitumumab provides a needed new treatment option to better overcome cancer’s escape mechanisms. The CodeBreaK 300 study showed superior progression-free survival compared to the investigated standard of care and represents a clinically meaningful benefit for patients with KRAS G12C-mutated metastatic colorectal cancer.”
“There is an immense need for continued innovation and precision medicine to help address metastatic colorectal cancer,” said Michael Sapienza, Chief Executive Officer of the Colorectal Cancer Alliance. “This new combination approach is an important breakthrough for patients with KRAS G12C-mutated metastatic colorectal cancer, offering a new beneficial treatment option for patients living with this devastating and challenging disease.”
