Real-world (RW) use of fixed-duration (FD) ibrutinib+venetoclax (Ibr+Ven) in patients (pts) with previously untreated chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL): Pooled analysis of REALITY-worldwide (WW) and REALITY-2 prospecti

Abstract Introduction FD Ibr+Ven is approved as first-line (1L) treatment (tx) for CLL/SLL in 78 countries across Asia, Europe, the Middle East, and South America, plus Australia, Canada, and New Zealand. Clinical trials with up to 5.5 years (yrs) of follow-up have demonstrated progression-free and overall survival benefits of 1L FD Ibr+Ven in pts with CLL/SLL (Wierda WG, ASH 2024; Jacobs R, EHA 2024). Despite established clinical benefits, there is a lack of RW evidence on the effectiveness and tolerability of FD Ibr+Ven outside of clinical trial settings. Here we present pooled data from REALITY-WW and REALITY-2 to understand the usage, factors for therapy decision, clinical response, and safety of FD Ibr+Ven in routine clinical practice. Methods REALITY-WW and REALITY-2 are prospective observational cohort studies. REALITY-WW is an international study; REALITY-2 is conducted in Germany. Both included previously untreated pts with CLL/SLL from hospitals and medical institutions where Ibr+Ven was routinely used. The decision to start FD Ibr+Ven was made prior to and independent of pt enrollment. Pts aged ≥18 yrs with a confirmed diagnosis of CLL/SLL requiring 1L tx per iwCLL 2018 criteria received 3 cycles of Ibr, followed by 12 cycles of FD Ibr+Ven orally (Ibr, 420 mg/d; Ven, 5-week ramp-up to 400 mg/d). Primary end point was overall response rate (ORR) per iwCLL 2018 criteria. Secondary end points and outcomes of interest included tx-emergent adverse events (TEAEs), tumor lysis syndrome (TLS) risk, and factors associated with physician decision to initiate FD Ibr+Ven in routine clinical practice. Results At data cutoff (REALITY-WW: May 2025; REALITY-2: March 2025), 129 pts from both studies received FD Ibr+Ven (REALITY-WW, 81; REALITY-2, 48). The median (range) time on study was 6.4 (0.1-19.0) months (mo). Median (range) age was 65.0 (37.0-87.0) yrs, with 46.5% of pts aged <65 yrs and 53.5% of pts aged ≥65 yrs; 62.8% were male. Median (range) time from diagnosis to FD Ibr+Ven initiation was 38.1 mo (0.1-238.0) and median (range) duration of tx was 6.0 mo (0.1-15.9) for Ibr and 3.2 mo (0.1-8.4) for Ven. A Cumulative Illness Rating Scale score of >6 was observed in 12.6% of pts, with a higher score in pts aged ≥65 vs <65 yrs (18.0% vs 6.9%). TP53 mutations were seen in 7.4% of pts; 52.8% had an unmutated IGHV status. ORR was assessed in the 44 pts with ≥ 1 post-baseline assessment in REALITY-WW. Of these, 39 showed a response by the end of 6 tx cycles (3 cycles of Ibr + 3 cycles of FD Ibr+Ven) and 5 had stable disease. ORR at 6 mo per iwCLL 2018 criteria (partial response [PR] with lymphocytosis [PR-L] or better) was 88.6% (95% CI, 79.3-98.0), including complete responses in 29.5%, PR in 34.1%, and PR-L in 25.0% pts. Among 129 treated pts, TEAEs were reported in 61.2%; diarrhea was the most common TEAE (14.0%). Serious TEAEs and grade 3/4 TEAEs were reported in 12.4% and 8.5% of pts, respectively. The most common grade 3/4 TEAE was myocardial infarction (1.6%). Dose reduction was observed in 13.2% (Ibr) and 2.3% (Ven) of pts, mainly due to tx-associated TEAE/toxicity/TLS. Rates of TEAEs leading to discontinuation, dose reduction, and interruption of ≥1 study tx were 4.7%, 10.9%, and 20.9%, respectively. At baseline (n=129), 18.6%, 45.0%, and 14.7% of pts had high, intermediate, and low TLS risk, respectively, while 20.2% were not assessed and 1.6% had missing data. After the 3-cycle Ibr lead-in, the distribution shifted to 9.3%, 24.8%, and 24.0%, respectively, with 14.7% not assessed and 27.1% missing. There were no TEAEs of TLS and no hospitalizations due to TLS. Seven pts (6 aged ≥65 yrs and 1 <65 yrs) were hospitalized prophylactically for TLS. Prophylactic hospitalization was observed in 8.5% (11/129) of pts with high or medium TLS risk and impaired renal function for whom the Ven ramp-up was initiated; no pts were hospitalized due to laboratory/clinical TLS during the Ven ramp-up period. Physician questionnaire responses (n=126) indicated the most common factors associated with decision to initiate FD Ibr+Ven were administration route advantage (91.3%), overall health status (87.3%), anticipated superior efficacy of tx (84.1%), and general risk factors such as high tumor burden/genetic risk factors (81.0%). Conclusions Overall findings suggest that FD Ibr+Ven is an effective and safe tx for pts with CLL/SLL in a RW population, including those aged ≥65 yrs. Data with longer follow-up will be presented at the meeting.