CHICAGO – The American Society of Clinical Oncology recently wrapped its annual meeting in Chicago. Here, I highlight some presentations that stood out to me.
A first-line treatment for metastatic colorectal cancer
The plenary session did not disappoint. In abstract LBA1, investigators presented first-line treatment for patients with metastatic colorectal cancer who were randomized to receive mFOLFOX6 with either bevacizumab or panitumumab in RAS wild-type positive patients. This was the phase 3 PARADIGM trial.
Dr. David H. Henry
The primary outcome for this study was overall survival. It included 823 patients who were randomized 1:1 with a subset analysis of whether the primary tumor was on the left or right side of the colon. At 61 months follow-up, the median overall survival results for left-sided colon cancer was 38 months versus 34 months. It was statistically significant favoring the panitumumab arm. It improved the curable resection rate for patients with left-sided tumors from 11% in the bevacizumab arm to 18% in the panitumumab arm. Interestingly, patients randomized with right-sided tumors showed no difference in overall survival. The investigator, Takayuki Yoshino, MD, PhD, National Cancer Center Hospital East, Kashiwa, Japan, said the study findings support the use of mFOLFOX6 with panitumumab in left-sided RAS wild type as first-line therapy in metastatic colorectal patients.
A possible new standard of care in breast cancer
Shanu Modi, MD, of Memorial Sloan Kettering Cancer Center, New York, received a standing ovation and deserved it. In the phase 3 clinical trial DESTINY-Breast04 (abstract LBA3), she demonstrated that trastuzumab deruxtecan (T-DXd) for patients with metastatic breast cancer who were HER2 low (IHC 1+ or 2+ ISH-), led to a statistically significant and clinically meaningful benefit in both progression free survival and overall survival. In this trial, patients were randomized 2:1 to receive trastuzumab deruxtecan or physician’s choice of chemotherapy. All patients had at least one to two lines of chemotherapy before entering the trial. Hormone-positive patients were allowed if they had already received and failed, or progressed on hormone therapy.
Previously, most patients were treated either with eribulin with some receiving capecitabine, gemcitabine or taxane, or hormone therapy if hormone positive.
The progression-free survival was 10.1 versus 5.4 months in hormone-positive patients, and in all patients (hormone receptor positive or negative), there was a likewise improvement of 9.9 versus 5.1 months progression free survival.
Overall survival was equally impressive. In the hormone receptor–positive patients, the hazard ratio was 0.64 with a 23.9 versus 17.5 month survival. If all patients were included, the HR was again 0.64 with 23.4 versus 16.8 month survival. Even the triple-negative breast cancer patients had a HR of 0.48 with 18.2 versus 8.3 months survival. Adverse events were quite tolerable with some nausea, some decreased white count, and only an interstitial lung disease of grade 2 or less in 12%.
Trastuzumab deruxtecan is a targeted treatment which, in addition to striking its target, also targets other tumor cells that are part of the cancer. The results of this study may lead to a new standard of care of this patient population.
The study by Dr. Modi and colleagues was simultaneously published in the New England Journal of Medicine.