GI Cancers Symposium 2020: Pertuzumab Plus Trastuzumab in HER2-Positive Colorectal Cancer
Posted: Friday, February 14, 2020
Although HER2 amplification occurs in about 5% to 7% of patients with colorectal cancer—not nearly as commonly as it does in breast and gastric cancers—results from a cohort of the Targeted Agent and Profiling Utilization Registry (TAPUR) study found that this subpopulation appeared to respond well to pertuzumab plus trastuzumab. The work respresents a potential treatment option that is safe for heavily pretreated HER2-positive patients, although further study is necessary to confirm these results. The findings were presented at the 2020 Gastrointestinal (GI) Cancers Symposium in San Francisco (Abstract 132).
“There are many medications that have been approved in various cancer types in heavily pretreated populations where the response rate is less than 10%,” Ranju Gupta, MD, of Lehigh Valley Health Network, Bethlehem, Pennsylvania, stated in an American Society of Clinical Oncology press release. “Very few patients have any partial response or complete response [at this stage of treatment]; we see more disease control at this stage rather than objective response.”
The research team evaluated 28 patients with HER2-positive colorectal cancer for safety and efficacy. All patients were treated with pertuzumab plus trastuzumab. Most of the patients (79%) were heavily pretreated and had received at least three prior treatment regimens.
The objective response rate was 14%, and the disease control rate was 50%. Of the overall patient pool, 4 patients achieved partial responses, and 10 patients remained stable for at least 16 weeks. The median progression-free survival was 17.2 weeks, and more than half of the patients (58%) were alive after 1 year of treatment. Treatment-related adverse events including anemia, infusion reaction, and left ventricular dysfunction were reported in two patients. Currently, the research team is continuing work on analyses by RAS mutation status.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.