“These results [from the TRIO-US B-12 TALENT trial] are exciting and impressive in HER2-low, hormone receptor–positive patients. The authors were testing the waters and got a positive signal,” said Jason Aboudi Mouabbi, MD, a medical oncologist at MD Anderson Cancer Center, Houston.

Jason Aboudi Mouabbi, MD

“The beauty of this is that hormone receptor–positive breast cancer does not respond well to neoadjuvant chemotherapy. Perhaps, we can use antibody-drug conjugates earlier in these patients to improve outcomes. However, it wasn’t compared with chemotherapy in this study,” he continued. “The single arm [of T-DXd (fam-trastuzumab deruxtecan-nxki)] did well in this trial. I would be really excited to see T-DXd compared with chemotherapy in a head-to-head comparison.”

Dr. Mouabbi continued: “The authors reported a 15% clinical complete response in combination with residual cancer burden [RCB] 0/1, which is better than what is achieved with neoadjuvant chemotherapy. It is exciting and encouraging.”

“Other antibody-drug conjugates have different targets. I predict that the next decade in cancer treatment will be the decade of antibody-drug conjugates,” he added.

Regarding HER2-low cancer, Dr. Mouabbi said it is very difficult to distinguish between HER2 0 and HER2 1. “I have had patients who were originally classified as HER2 0, and upon recheck, they will almost always be labeled as HER2 1+ or HER2-low. The line is blurry. We want to be able to find the low expressors because we don’t want to deny patients this treatment,” he explained. 

DISCLOSURE: Dr. Mouabbi has received honoraria from BostonGene, GE HealthCare, Cardinal Health, Napo Pharmaceuticals, and Fresenius Kabi.