P647: RACIAL DISPARITIES IN REAL-WORLD TREATMENT PATTERNS AND OUTCOMES AMONG PATIENTS WITH CLL

Background: Treatment outcomes for patients with chronic lymphocytic leukemia (CLL) have improved with the introduction of targeted agents. Prior research has shown that Black patients (pts) with CLL had shorter survival compared to White non-Hispanic pts. Here, we assess for the first time if there are disparities for Black pts in treatment options and outcomes in real-world clinical practice in the contemporary era of targeted agents. Aims: To assess demographic, clinical, and treatment characteristics and outcomes in first-line (1L) therapy for Black and White pts. Methods: From the 19 US-based centers of the CLL Collaborative Study of Real-World Evidence (CORE), a retrospective, international, observational study, adult Black and White non-Hispanic pts with CLL were selected if they initiated 1L therapy on/after 01/01/2014 outside of clinical trials and classified into 2 mutually exclusive cohorts. Cohorts were balanced using stabilized inverse probability treatment weighting (S-IPTW) on sex, age at 1L, year of 1L, time from CLL diagnosis to 1L, insurance type, ECOG, Rai stage, IGHV, del(17p)/TP53 mutations, and number of comorbidities. Balance was assessed using standardized mean difference and variance ratio. Demographic, clinical, and treatment characteristics were assessed at 1L start. 1L treatment outcome was progression-free survival (PFS). Results: Of the 979 pts included, 110 pts (11.2%) were Black, 336 (34.3%) female (Black: 40[36.4%], White: 296[34.1%]), median age at diagnosis was 63.3 years (Black: 63.3, White: 63.3) with a median follow-up of 22.4 months (mos; Black: 20.2, White: 23.2). Before weighting, Black pts were younger at 1L start (median age: 64.4 vs 66.6), had a higher proportion of pts on Medicaid/no insurance (10.9% vs 3.3%), lacked Rx benefits (10% vs 3.8%), and started 1L sooner after CLL diagnosis (2.8 vs 20.9 mos) relative to White pts. Black pts also had a higher proportion with unmutated IGHV (75.8% vs 62.9%), ATM (16.2% vs 9.3%), and NOTCH1 (8.1% vs 4.2%) mutations, higher comorbidity burden (median number of comorbidities: 2 vs 1), and a lower proportion of pts with 17del/TP53 mutations (13.6% vs 17.9%) relative to White pts. Similarly, a higher proportion of Black pts had only 1 line of treatment (65.5% vs 62.1%), never received a targeted agent during follow-up (30.0% vs 23.2%), and were treated with CT/CIT in 1L (48.2% vs 34.4%); between 2014-2016 (63.3% vs 48.9%) relative to 2017-2022 (37.9% vs 23.9%). Median 1L treatment duration was ~14 mos in both cohorts. Median PFS was 14.8 mos shorter for Black than White patients (Figure 1). After weighting, the cohorts were well-balanced in their characteristics, yet the median PFS remained shorter for Black than White pts (10.4 mos shorter); 11.6 mos shorter in 2014-2016 though not in 2017-2022 (1.8 mos longer; Figure 1). Summary/Conclusion: Racial disparities were observed in clinical characteristics, comorbidity burden, and type of therapy at the time of treatment initiation for 1L CLL, resulting in a large disadvantage in the median PFS for Black pts in the years immediately following the advent of targeted agents. However, after weighting, this difference in the median PFS was attenuated relative to White pts. These data suggest that access to adequate care with more effective targeted treatments may help reduce racial disparities for pts in real-world settings, as well as reducing their comorbidity burden. Our study highlights the importance of inclusion of pts from different backgrounds in clinical trials to study clinical outcomes prospectively.Keywords: Chronic lymphocytic leukemia