Summary
Pts with mTNBC have poor prognosis and limited treatment options. SG is an anti—Trop-2 antibody-drug conjugate approved in multiple countries for pts with mTNBC who received at least 1 prior systemic therapy and in the US for pts with pretreated HR+/HER2- mBC. In the pivotal phase 3 ASCENT study (NCT02574455), SG demonstrated superior efficacy over single-agent chemotherapy and a manageable safety profile in pts with mTNBCardia A, et al. NEJM. 2021). This study is, to our knowledge, the first to describe real-world treatment patterns and dosing with SG and its impact on clinical outcomes in pts with mTNBC in the US.
Methods
This retrospective, observational cohort study used the ConcertAI Patient360™ dataset with additional curated electronic medical record data from the US. Pts (≥18 years) diagnosed with mTNBC as defined according to the current American Society of Clinical Oncology/College of American Pathologists guidelines (HER2 IHC0, 1, or 2/ISH-negative; ER/PR <1%) and initiating treatment with SG (index date) in 2L+ from April 2020 to May 2022 were included. Real-world clinical outcomes with SG and use patterns were assessed. Kaplan-Meier method was used to determine real-world overall survival (rwOS).
Results
In total, 230 pts met the eligibility criteria and were included for analysis. All pts were female; 64% were White and 26% Black; median age was 60 years (IQR, 49-69); 71% of pts presented with ECOG performance status ≤1; 71% had visceral metastases and 7% had brain metastases at baseline. The median time from mBC diagnosis to SG treatment initiation was 11.8 months (IQR, 7.6-19.2). Most pts (66%) were treated in a community setting; 34%, 28%, 19%, and 20% of pts were treated with SG in the 2L, 3L, 4L, and 5L+ setting, respectively. Between 2020-2022, there was a trend in the distribution of SG use shifting to earlier line settings, see Table. Median starting dose was 10 mg/kg (IQR, 9.8-10.1). Median follow-up duration was 7.2 months (IQR, 3.9-11.1). Median rwOS (95% CI) from index date was 10 months (8.3-11.1) among all pts. Median rwOS (95% CI) was 13.9 months (9.79-not estimable) and 8.4 months (7.7-10.3) among pts treated with SG in 2L and in 3L+ setting, respectively. Analyses on real-world patterns of SG use are ongoing and additional results will be provided.
Conclusions
Pts who were treated with SG in routine clinical practice were older, more ethnically diverse, and presented with worse performance status than pts enrolled in the ASCENT trial but demonstrated a similar survival benefit. The proportion of pts treated with 2L SG increased from 2020 to 2022, reflecting an expected dynamic of post approval drug uptake in routine practice.
