Sacituzumab govitecan (SG) improves progression-free survival (PFS), when compared with other single-agent therapies, in patients with heavily pretreated, advanced breast cancer, according to phase 3 data.
SG was associated with a 34% reduction in the risk of progression or death, when compared with physician’s choice of monotherapy. A higher proportion of patients in the SG arm were alive and free of progression at all landmark time points.
“Sacituzumab demonstrated a significant and clinically meaningful benefit … and should be considered a potential treatment option in this patient population,” said Hope S. Rugo, MD, of the University of California, San Francisco.
Dr Rugo presented these results, from the TROPiCS-02 study, at the 2022 ASCO Annual Meeting.
The phase 3 study (ClinicalTrials.gov identifier: NCT03901339) enrolled patients with hormone receptor-positive, HER2-negative, unresectable, locally advanced or metastatic breast cancer.
The patients had received 2 to 4 prior lines of chemotherapy for metastatic disease. Most had received chemotherapy in the (neo)adjuvant setting, and most had received prior endocrine therapy in the metastatic setting.
The patients were randomly assigned to receive SG (272 patients) or physician’s choice of treatment (271 patients), which included capecitabine, eribulin, vinorelbine, and gemcitabine.
The vast majority of patients in both treatment arms were women (99%) and had visceral metastases at baseline (95%). The median age was 57 years (range, 29-86) in the SG arm and 55 years (range, 27-78) in the physician’s choice arm.
At a median follow-up of 10.2 months, the median PFS was significantly longer with SG than with physician’s choice — 5.5 months and 4 months, respectively (hazard ratio, 0.66; 95% CI, 0.53-0.83; P =.0003).
At 6 months, the PFS rate was 46.1% in the SG arm and 30.3% in the physician’s choice arm. At 12 months, the PFS rates were 21.3% and 7.1%, respectively.
Dr Rugo noted that the PFS benefit seen with SC was consistent across predefined subgroups, including among patients with at least 3 prior chemotherapy regimens in the metastatic setting, those with visceral metastases, and those 65 years of age or older.
There was no significant difference in overall survival (OS) between the SG and physician’s choice groups. The median OS was 13.9 months and 12.3 months, respectively (hazard ratio, 0.84; 95% CI, 0.67-1.06; P =.143).
Dr Rugo noted, however, that the OS data are not mature, and follow-up is ongoing. She also said the safety profile of SG was consistent with that seen in prior studies.
Grade 3 or higher treatment-emergent adverse events were more common in the SG arm than in the physician’s choice arm — 74% and 60%, respectively. There was 1 treatment-related death in the SG arm, and there were no such deaths in the physician’s choice arm.
Disclosures: This study was supported by Gilead Sciences. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Rugo HS, Bardia A, Marmé F, et al. Primary results from TROPiCS-02: A randomized phase 3 study of sacituzumab govitecan (SG) versus treatment of physician’s choice (TPC) in patients (pts) with hormone receptor–positive/HER2-negative (HR+/HER2-) advanced breast cancer. Presented at ASCO 2022; June 3-7, 2022. Abstract LBA1001.