Sacituzumab govitecan improves overall survival (OS), when compared with physician’s choice of treatment, in patients with hormone receptor (HR)-positive, HER2-negative advanced breast cancer, according to updated results from the TROPiCS-02 study.

This statistically significant and clinically meaningful OS benefit supports the use of sacituzumab govitecan as a novel therapy for this patient population, according to Hope S. Rugo, MD, of the University of California, San Francisco. Dr Rugo presented these results at ESMO Congress 2022. 

The phase 3 TROPiCS-02 study (ClinicalTrials.gov Identifier: NCT03901339) enrolled patients with previously treated, HR+, HER2- locally recurrent or metastatic breast cancer. Patients had received at least 1 taxane, endocrine therapy, and CDK4/6 inhibitor in any setting. They had also received 2-4 chemotherapy regimens in the metastatic setting. 


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The patients were randomly assigned to receive sacituzumab govitecan (n=272) or physician’s choice of treatment (n=271). Physician’s choice included capecitabine, vinorelbine, gemcitabine, or eribulin. Patients in both arms were treated until progression or unacceptable toxicity. 

The median ages at baseline were 57 (range, 29-86) years in the sacituzumab govitecan arm and 55 (range, 27-78) years in the comparator arm. The median number of prior chemotherapy regimens for metastatic disease was 3 in each group. 

The study’s primary endpoint was progression-free survival (PFS). Prior results showed a significant improvement in PFS with sacituzumab govitecan. At a median follow-up of 10.2 months, the median PFS was 5.5 months with sacituzumab govitecan and 4.0 months with physician’s choice of therapy (hazard ratio [HR], 0.66; 95% CI, 0.53.-0.83; P =.0003).

In the current analysis, the median follow-up was 12.5 months. The median OS was significantly longer in the sacituzumab govitecan arm than in the comparator arm — 14.4 months and 11.2 months, respectively (HR, 0.79; 95% CI, 0.65-0.96; P =.020). The 12-month OS rates were 61% and 47%, respectively. 

The OS benefit with sacituzumab govitecan was generally consistent across predefined subgroups, including among patients who received 3 or more prior chemotherapy regimens in the metastatic setting, patients with visceral metastases, and those who had received prior endocrine therapy in the metastatic setting for at least 6 months.

The objective response rate was 21% in the sacituzumab govitecan arm and 14% in the comparator arm (odds ratio, 1.63; 95% CI, 1.03-2.56; P =.035). The median duration of response was 8.1 months and 5.6 months, respectively. 

In a quality of life (QOL) analysis, the median time-to-deterioration (TTD) of global health status/QOL was 4.3 months in the sacituzumab govitecan arm and 3.0 months in the comparator arm (HR, 0.75; 95% CI, 0.61-0.92; P =.006). 

The median TTD for fatigue was 2.2 months in the sacituzumab govitecan arm and 1.4 months in the comparator arm (HR, 0.73; 95% CI, 0.60-0.89; P =.002). For pain, results were similar between the treatment arms (HR, 0.92; 95% CI, 0.75-1.13; P =.415).

Safety results for the sacituzumab govitecan arm were consistent with prior results, and no new safety signals were observed.

Disclosures: This research was supported by Gilead Sciences, Inc. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Rugo HS, Bardia A, Marmé F, et al. Overall survival (OS) results from the phase III TROPiCS-02 study of sacituzumab govitecan (SG) vs treatment of physician’s choice (TPC) in patients (pts) with HR+/HER2- metastatic breast cancer (mBC). Presented at ESMO 2022; September 9-13, 2022. Abstract LBA76.