Debu Tripathy, MD, Professor and Chair of Breast Medical Oncology at The University of Texas MD Anderson Cancer Center, Houston, shared his thoughts on TROPiCS-02 with The ASCO Post. He said the study is important because it addresses the needs of “a population with limited options, whose disease-free survival is short.” 

Dr. Tripathy continued: “Patients were enrolled after [at least] two lines of therapy, and they did, in fact, benefit. It was a small absolute benefit, but in relationship to their expected progression-free survival, it was still a 34% improvement. When you look at their other options, you have to realize this [sacituzumab govitecan] is better.”

However, Dr. Tripathy cautioned that quality-of-life data will be important, and those details have not yet been reported. He said the primary toxicities of sacituzumab govitecan are gastrointestinal side effects and cytopenias, which pose a risk for infections. 

Debu Tripathy, MD

When asked how sacituzumab govitecan, which is so powerful in triple-negative tumors, might be exerting an effect in estrogen receptor–positive tumors as well, Dr. Tripathy offered a few possibilities. As Dr. Rugo also proposed, he said some tumors may have had estrogen receptor–negative subclones that grew over time, contributing to the drug’s benefit. But perhaps more importantly, the effect may be a consequence of how antibody-drug conjugates work: “by being specifically directed into the cell, which offers an advantage over other chemotherapies,” he explained. 

“This is a different type of chemotherapy, a topoisomerase-1 inhibitor, as is fam-trastuzumab deruxtecan-nxki,” he said. “So, part of the benefit may just be these chemotherapies are a chemotherapy type that these patients have generally not seen before.” 

DISCLOSURE: Dr. Tripathy has served as a consultant to Gilead, AstraZeneca, GlaxoSmithKline, Novartis, and Oncopep and has received institutional research support from Pfizer and Novartis.