Abstract PO2-18-03: Comparison of Provider Adoption of Antibody-Drug Conjugates Among Breast Cancer Patients (pts) and Impact on Duration of Therapy (DOT)
Authors: Choksi Rushir , Gorantla Vikram , Gart Mike , Blanc Simon , Alwon Erin , Brenneman Dawn , Varughese Prateesh , Scott Justin , Katzen Harvey 
Published: May 2024

Background: An assessment was performed to understand the degree of post-approval provider adoption of two antibody-drug conjugates, fam-trastuzumab deruxtecan-nxki (FTD) and sacituzumab govitecan-hziy (SG), to treat breast cancer in the community oncology setting. In addition, an evaluation was performed to assess pt DOT based on the volume of pts on those therapies treated by each provider. In breast cancer, FTD was initially approved in the U.S. on December 20, 2019, and SG was initially approved in the U.S. on April 22, 2020.

Methods: This assessment used the Integra Connect PrecisionQ real-world de-identified database of over 2 million cancer pts across 500 sites of care to assess SG and FTD treatment use by provider and DOT for those treated with SG and FTD. It included only breast cancer pts treated with SG or FTD who started after the initial approval dates of the respective therapies. In analyzing the DOT, pts were required to have had a follow-up of 12 months or greater, and only monotherapy treated pts were included to rule out any additional confounders. The FTD pts included were treated between December 2019 to May of 2023, whereas the SG pts included were treated between April 2020 to May 2023. Comparisons of proportions were conducted using a two sample two-tailed z-test and compared median DOT using a Wilcoxon Rank Sum Test. Descriptive analyses were used to summarize pt demographic statistics.

Results: 827 pts treated with SG were identified across 376 providers, with an average age at SG treatment start of 60.2 (median of 61); 14% of pts identified as Black or African American and 59% identified as White or Caucasian. Among 827 pts treated with SG across 376 providers, 23% of pts were treated by providers who treated 6 or more pts with SG, which accounted for 6% of all providers. 23% of pts were found to be treated by a provider who used only SG once, which accounted for 56% of all providers. The median DOT among providers who treated 6 or more pts with SG was 168 days (N = 83) compared to 110 days (N = 303) among providers who treated 5 or less pts (p &lt; 0.01). The median DOT for all SG pts was 119 days (N = 386). Of the 1438 pts treated with FTD, the average age at FTD treatment start was 62.1 (median of 63), with 8% of pts identified as Black or African American and 54% identified as White or Caucasian. Among 1438 pts treated with FTD across 485 providers, 38% of pts were treated by providers who treated 6 or more pts with FTD, which accounted for 12% of all providers. 14% of pts were found to be treated by a provider who only used FTD once, which accounted for 40% of all providers. The median DOT among providers who treated 6 or more pts with FTD was 281 days (N = 158) compared to 263 days (N = 234) among providers who treated 5 or less pts (p &gt; 0.05). The median DOT for all FTD pts was 269 days (N = 392). The difference in the number of pts treated by a provider who used SG once (23% of 827 pts) vs. the number of pts treated by a provider who used FTD once (14% of 1438 pts) was found to be statistically significant (p &lt; .01). The difference in pts treated by a provider who used SG in 6 or more pts (23% of 827 pts) vs. compared to providers who used FTD in 6 or more pts (38% of 1438 pts) was found to be statistically significant (p &lt; .01).

Conclusion: A large percentage of providers have only used the respective antibody-drug conjugates once (for SG it was 56% of all providers; for FTD 40%), which suggests an opportunity for greater awareness and guidance around effective therapy use and management of antibody-drug conjugates. Providers who used SG more often (6 or more pts) showed a longer DOT for their SG treated pts compared to those providers who used SG in 5 or less pts. This suggests that the slower adoption of SG and lack of experience across the community oncology provider base may be impacting overall pt DOT on SG.

Citation Format: Rushir Choksi, Vikram Gorantla, Mike Gart, Simon Blanc, Erin Alwon, Dawn Brenneman, Prateesh Varughese, Justin Scott, Harvey Katzen. Comparison of Provider Adoption of Antibody-Drug Conjugates Among Breast Cancer Patients (pts) and Impact on Duration of Therapy (DOT) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-18-03.