Looking Ahead
Dr. Tolaney highlighted that the cohort size of this study was small and the follow-up time was insufficient to draw conclusions about survival outcomes. Larger studies with long-term follow-up are needed to confirm the efficacy of first-line atezolizumab plus sacituzumab govitecan, she said.
“While this was a small study, the response data is very intriguing, with 17% of patients experiencing complete responses. The PFS data are also impressive, and there seems to be an interesting trend towards better response in patients with high Trop-2 expression and those with high levels of stromal TILs,” she added.
Dr. Tolaney also noted that the response rates and PFS data presented are similar to those of one of the treatment arms in the BEGONIA trial (NCT03742102), which investigated different combinations of immunotherapy in patients with metastatic TNBC. Like MORPHEUS-pan BC (NCT03424005), this study evaluated the efficacy of a different antibody-drug conjugate with chemotherapy. Patients in the study arm of the BEGONIA trial she was referring to received durvalumab (an anti-PD-L1 agent) and datopotamab deruxtecan (an antibody-drug conjugate).
Dr. Schmid said that biomarker analyses are ongoing to assess whether there is a correlation between Trop-2 expression levels and the benefits of sacituzumab govitecan. Studies are also needed to determine whether this combination can improve pathologic complete response rates in early-stage TNBC.
Dr. Tolaney echoed the importance of evaluating the efficacy of antibody-drug conjugates plus immune checkpoint inhibitors in different settings, including patients with PD-L1–negative or immunologically cold tumors and those with early-stage disease. “Ultimately, we want this combination treatment to move forward to early-stage TNBC to see if we could cure more patients,” she said, during the discussion.
Dr. Schmid reported financial relationships with Pfizer, AstraZeneca, Novartis, Gilead, Roche, Merck, MSD, BI, Seagen, Amgen, Bayer, Eisai, Celgene, Lilly, and Puma (consulting or advisory roles); Pfizer, AstraZeneca, Novartis, Gilead, Roche, Merck, MSD, BI, Seagen, Amgen, Bayer, Eisai, Celgene, Lilly, and Puma (honoraria); and AstraZeneca, Genentech, Roche, Oncogenex, Novartis, Astellas, and Medivation (research funding). Dr. Tolaney reported financial relationships with Novartis, Pfizer, Merck, Eli Lilly, AstraZeneca, Genentech/Roche, Eisai, Sanofi, Bristol Myers Squibb, Seattle Genetics, CytomX Therapeutics, Daiichi Sankyo, Gilead, Ellipses Pharma, 4D Pharma, OncoSec Medical Inc., Beyond Spring Pharmaceuticals, OncXerna, Zymeworks, Zentalis, Blueprint Medicines, Reveal Genomics, ARC Therapeutics, Infinity Therapeutics, Myovant, Zetagen, Umoja Biopharma, Menarini/Stemline, Aadi Biopharma, Bayer, and Jazz Pharmaceuticals (consulting or advisory roles); Genentech/Roche, Merck, Exelixis, Pfizer, Lilly, Novartis, Nanostring, Bristol Myers Squibb, Eisai, AstraZeneca, Gilead, Cyclacel, Sanofi, and Seattle Genetics (research funding).