Dr. Weinberg on Targeted Therapies for Molecular Subsets of mCRC

Benjamin Weinberg, MD, assistant professor of medicine, Division of Hematology and Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, discusses treatment strategies for patients with different molecular subtypes of metastatic colorectal cancer (mCRC).

BRAF-mutant mCRC is typically associated with a poor prognosis; however, targeted treatment regimens such as vemurafenib (Zelboraf), irinotecan, and cetuximab (Erbitux), as well as encorafenib (Braftovi), binimetinib (Mektovi), and cetuximab have both shown benefit in later-line settings for this patient population.

Additionally, patients with rectal cancer who harbor HER2 amplifications may benefit from HER2-targeted therapies in later-line settings, adds Weinberg.

Patients with microsatellite instability—high tumors account for about 4% of all patients with mCRC, says Weinberg. Treatment with anti–PD-1 therapies such as pembrolizumab (Keytruda) or nivolumab (Opdivo), in combination with anti–CTLA4 therapies like ipilimumab (Yervoy) appear to be of benefit.

Finally, patients with NTRK fusions appear to respond to larotrectinib (Vitrakvi) and entrectinib (Rozlytrek). Though rare, it is important to be aware of these fusions, concludes Weinberg.