Introduction: The most effective chemoimmunotherapy (CIT) in previously untreated CLL is the combination of fludarabine, cyclophosphamide and rituximab (FCR). Ibrutinib (I), the first irreversible inhibitor of Bruton's tyrosine kinase approved for CLL, has improved outcomes in numerous clinical trials compared to different CIT. Methods: FLAIR (ISRCTN01844152) is an ongoing, phase III, multicentre, randomised, controlled, open, parallel group trial for previously untreated CLL requiring therapy according to the IWCLL 2008 guidelines. Patients over 75 years or with >20% 17p-deleted cells were excluded. Participants were randomised on a 1:1 basis to receive 6 cycles of FCR (oral fludarabine 24mg/m 2/day for 5 days, oral cyclophosphamide 150mg/m 2/day for 5 days with IV rituximab [375 mg/m 2 on day 1/2 of cycle 1; 500 mg/m 2 on day 1 of cycles 2-6]) every 28-days or IR (Ibrutinib [420mg/day] plus rituximab [6 doses as for FCR]) given for up to 6 years with stratification by disease stage, age, gender and centre. The primary endpoint was to assess whether IR was superior to FCR in terms of investigator-assessed PFS. Secondary endpoints included overall survival,; attainment of undetectable MRD; response to therapy; safety and toxicity; health-related quality of life and cost-effectiveness. A formal interim analysis was planned when 191 events were observed in both arms or 109 events in the FCR arm alone with a p-value of 0.005 leading to reporting of the trial. Here we report the results of this planned interim analysis. Results: A total of 771 patients were randomised (385 to FCR and 386 to IR) from 113 UK Centres between 9/19/2014 and 7/19/2018. The data was locked on 5/24/2021. 73.3% were male, median age was 62 years (33.6% >65yo) and 45.1% were Binet Stage C. IGHV data was available for 728 (94.4%) patients with 53.2% IGHV unmutated (≥98% homology to germline), 40.5% IGHV mutated and 6.3% Subset 2. Hierarchical FISH testing revealed 0.4% 17p del, 15.4% 11q del, 12.3% trisomy 12, 29.7% normal and 35% 13q del; with 7.1% failed. The arms were well-balanced for disease variables with no significance differences. Median follow-up was 52.7 months. IR had a superior PFS compared to FCR (Median PFS not reached for IR versus 67 months for FCR; HR: 0.44; p<0.001; see Figure). The PFS was significantly better for IR in patients with IGHV unmutated CLL (HR: 0.41; p<0.001), but not for patients with IGHV mutated CLL at this follow-up (HR: 0.66; p=0.179). There was no difference in overall survival between the two arms (HR: 1.01; p=0.956) with a total of 29 deaths in FCR arm (including 4 from CLL, 3 Richter's [RT], 3 AML/MDS, 3 COVID-19 and 2 cardiac/sudden) and 30 in the IR arm (including 3 CLL, 1 RT, 0 AML/MDS, 3 COVID-19 and 8 cardiac/sudden). Second line treatment was initiated for 59 patients after FCR (including 38 BTKi, 7 venetoclax+R [venR], 4 BendamustineR [BR] and 3 CHOP-R [RT]) and 21 after IR (including 7 FCR, 5 venR, 1 BR, 1 CHOP-R [RT], 1 ABVD [Hodgkin's]). Overall, 88.1% of patients have received targeted therapies for CLL progression after FCR. The overall survival with FCR in FLAIR is significantly improved compared to FCR in previous NCRI trials (ADMIRE and ARCTIC) which had the same inclusion criteria, the same Centres and an identical FCR schedule, but were conducted prior to widespread availability of targeted therapies in the relapse (recruited between 2009 and 2012). The 4 year overall survival for FCR in FLAIR was 94.5% compared to 84.2% for FCR between 2009 and 2012. SAEs were reported in 53.7% of patients on FCR and 53.4% on IR. Notable differences for SAEs by organ class for FCR vs IR: infections in 33.6% of patients vs 27.1%; blood and lymphatic in 19.8% vs 10.7%; and cardiac in 1.1% vs 8.3%. With current follow-up, there were 10 sudden or cardiac deaths: 8 IR and 2 FCR. Further analysis indicated that 7 of the 8 cardiac or sudden deaths in the IR arm had a history of hypertension or cardiac disease (further detailed in additional abstract; Munir et al.). Neither of the sudden deaths in the FCR arm had a prior cardiac or hypertensive history or were on cardiac or anti-hypertensive treatment. There were 6 cases of secondary MDS/AML in the FCR arm and 1 in the IR arm. Conclusion: Ibrutinib plus rituximab resulted in a superior PFS compared to FCR. There was no difference in overall survival, most likely due to effective second-line targeted therapy in patients progressing after FCR. Figure 1 Figure 1. Disclosures Hillmen: Janssen: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; AbbVie: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Pharmacyclics: Honoraria, Research Funding; Roche: Research Funding; Gilead: Research Funding; SOBI: Honoraria; BeiGene: Honoraria; AstraZeneca: Honoraria. Bloor: Novartis: Honoraria; Kite, a Gilead Company: Honoraria. Broom: AbbVie: Honoraria; AstraZeneca: Honoraria; Janssen-Cilag Ltd: Honoraria; Takeda UK Ltd: Honoraria; Celgene Ltd: Honoraria; Gilead: Honoraria. Furtado: Abbvie: Other: Conference support. Morley: Kite: Honoraria; Janssen: Honoraria; AbbVie; Takeda: Other: Conference support; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Conference support. Cwynarski: Adienne, Takeda, Roche, Autolus, KITE, Gilead, Celgene, Atara, Janssenen: Other. Paneesha: Celgene: Honoraria; Roche: Honoraria; Janssen: Honoraria; Gilead: Honoraria; Bristol Myers Squibb: Honoraria; AbbVie: Honoraria. Howard: Roche: Current Employment. Cairns: Merck Sharpe and Dohme: Research Funding; Amgen: Research Funding; Takeda: Research Funding; Celgene / BMS: Other: travel support, Research Funding. Patten: NOVARTIS: Honoraria; ROCHE: Research Funding; JANSSEN: Honoraria; ASTRA ZENECA: Honoraria; ABBVIE: Honoraria; GILEAD SCIENCES: Honoraria, Research Funding. Munir: F. Hoffmann-La Roche: Consultancy; Alexion: Honoraria.

No abstract

No abstract

No abstract

Introduction: Ibrutinib (Ibr) is the first approved irreversible BTK inhibitor. Cardiovascular (CV) adverse events, include hypertension (HT) and atrial fibrillation (AF). Ventricular tachyarrhythmias and sudden death have been reported possibly due to off target kinase inhibition. Several randomised Phase III trials have reported low numbers of cardiac deaths, sudden/unexplained deaths, and/or ventricular arrhythmias with Ibr including 9 deaths in RESONATE-2 Trial, 11 unexplained or unwitnessed deaths in Alliance Trial A041202 (med age 71; Ibr (n=7 [4%]), Ibr+ritux (IR; 4 [2%]), one death in the IR arm of ECOG1912 Trial (mean age 56.7) and 3 unexplained plus 5 cardiac deaths with BR + Ibr in the HELIOS trial (med age 64). Methods: FLAIR, a phase III, multicentre, randomised, controlled, open, trial recruiting 771 pts with untreated CLL requiring therapy. Pts were ≤75 years, considered fit for FCR and were randomized to IR or FCR. Pts with inadequately controlled symptomatic cardiac failure or unstable angina were excluded. We conducted ad hoc evaluations of the potential association of sudden or cardiac deaths with prior medical history or therapies for cardiac disorders (AF, Ischaemic heart disease, MI or angina) and HT via univariate analyses. We used Fisher's Exact test and estimated relative risk (RR) and associated confidence intervals under a normal approximation. Results: In FLAIR, 384 and 378 pts were treated with IR and FCR, respectively, median 52.7 months FU and treatment durations of 47.2 and 4.7 months. Median age 62. 84/384 (22%) IR pts had pre-existing HT and 17/384 (4%) a prior history of a cardiac disorder. 74/378 (20%) FCR pts had HT and 18/378 (5%) a cardiac disorder. To date 10 pts had a sudden or cardiac death: 2 (0.5%) FCR and 8 (2%) IR - median 33 mo (range: 13-48) from initiating IR to death. 9/10 pts were male aged 54 to 73 years at randomisation. 7/ 8 IR pts experiencing a sudden or cardiac death, had a prior history of HT and/or cardiac disorder (RR 23.6 vs pts with no HT/CV history, 95%CI [2.9-195]; Fisher's Exact P=0.0003; Table 1). Hypertensive cardiomyopathy and/or coronary artery disease was found at post mortem of all 3 IR pts having a PM. The risk of sudden or cardiac death with IR was 0.3% (1/291) in pts without pre-existing risk. The number of pts taking anti-hypertensives at trial entry (some taking more than one class) was: ACE inhibitors (ACEi) 47 IR, 37 FCR; Angiotensin II receptor blockers (ARB's) 15 IR, 17 FCR; Ca channel blockers 30 IR, 34 FCR; B-blockers 24 IR, 20 FCR; Diuretics 13 IR, 16 FCR; and alpha blockers 7 IR, 5 FCR. Overall, 291/384 (76%) IR and 296/378 (78%) FCR were taking no HT or cardiac medications at trial entry. The use of ACEi at study entry was associated with an increased risk of sudden or cardiac death with IR: 7/47 (15%) pts on ACEi at trial entry had a sudden or cardiac death compared to 1/336 (0.3%) not taking ACEi (RR 50.2, 95%CI [6.3-399]; P < 0.0001; Table 1). 2/7 pts had discontinued ACEi and switched to ARB's due to cough sometime prior to death. In contrast 0/37 FCR pts with a history of HTN/CV taking ACEi experienced a sudden or cardiac death. In the IR arm, none of the 46 pts receiving cardiac medication but not ACEi had a sudden or cardiac death suggesting that the risk was not simply a prior history of HT or cardiac disorder. 3/11 (27%) IR pts taking an ACEi plus a beta blocker at study entry had a sudden or cardiac death vs 4/32 (12.5%) pts on ACEi without a beta blocker. Factors potentially confounding the interpretation: 1) analyses did not take into account severity of underlying HT/CV risk, as it is possible that pts on ACEi had more severe underlying CV disease than others; and 2) analyses did not adjust for changes in HT/CV medications during the course of the study. However, the lack of any such signal in pts with a prior cardiovascular/HT history on therapies other than ACEi suggests a potential association with the medication itself. Conclusion: Sudden or cardiac deaths seen on IR in FLAIR were observed predominantly among male pts with a prior history of HT or cardiac disease. The prior use of ACEi was correlated with the risk of sudden or cardiac death in IR pts. In contrast, pts treated with IR who were not on ACEi (regardless of medical history) had a very low rate of cardiac or sudden death. Whilst these findings need confirming in other Ibr trials we believe that caution should be taken when concurrently administering ibrutinib and ACE inhibitors in pts with a medical history of HT or CV disease. Figure 1 Figure 1. Disclosures Munir: F. Hoffmann-La Roche: Consultancy; Alexion: Honoraria. Bloor: Novartis: Honoraria; Kite, a Gilead Company: Honoraria. Broom: AbbVie: Honoraria; AstraZeneca: Honoraria; Janssen-Cilag Ltd: Honoraria; Takeda UK Ltd: Honoraria; Celgene Ltd: Honoraria; Gilead: Honoraria. Furtado: Abbvie: Other: Conference support. Morley: Roche: Membership on an entity's Board of Directors or advisory committees, Other: Conference support; AbbVie; Takeda: Other: Conference support; Janssen: Honoraria; Kite: Honoraria. Cwynarski: Atara: Consultancy; BMS/Celgene: Other; Celgene: Consultancy; Gilead: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Janssen: Consultancy, Other; Kite, a Gilead Company: Consultancy, Speakers Bureau; Roche: Consultancy, Other, Speakers Bureau; Takeda: Consultancy, Other, Speakers Bureau. Gatto: Roche: Consultancy. Paneesha: AbbVie: Honoraria; Bristol Myers Squibb: Honoraria; Gilead: Honoraria; Janssen: Honoraria; Roche: Honoraria; Celgene: Honoraria. Fox: F. Hoffmann-La Roche Ltd: Consultancy, Membership on an entity's Board of Directors or advisory committees. Howard: Roche: Current Employment. Cairns: Takeda: Research Funding; Amgen: Research Funding; Merck Sharpe and Dohme: Research Funding; Celgene / BMS: Other: travel support, Research Funding. Patten: NOVARTIS: Honoraria; ASTRA ZENECA: Honoraria; ABBVIE: Honoraria; JANSSEN: Honoraria; GILEAD SCIENCES: Honoraria, Research Funding; ROCHE: Research Funding. Hillmen: BeiGene: Honoraria; SOBI: Honoraria; AstraZeneca: Honoraria; Gilead: Research Funding; Roche: Research Funding; Pharmacyclics: Honoraria, Research Funding; AbbVie: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Janssen: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding.