ABSTRACT
Background: Infectious complications are a major cause of morbidity and mortality in Chronic Lymphocytic Leukaemia (CLL). Therapeutic approaches that deplete CLL cells also affect normal B-cells. Optimal treatment would result in eradication of CLL cells and recovery of normal immune function. FLAIR (ISRCTN01844152) is a phase III trial for previously untreated CLL comparing ibrutinib plus rituximab (IR) with fludarabine, cyclophosphamide and rituximab (FCR) and subsequently amended to also compare ibrutinib plus venetoclax (I+V) and ibrutinib alone (I) with FCR. Measurable residual disease (MRD) and normal B-cell levels were assessed at multiple timepoints. Aims: To assess the depletion of normal B-cells during treatment and recovery after end of treatment. Methods: Participants aged under 75 years with <20% TP53-deleted cells were initially randomised to FCR or IR and subsequently to FCR, IR, I+V or I with the IR arm closed after randomisation of 771 participants to FCR/IR. FCR was given for 6 cycles, while treatment in the IR, I and I+V arms continued for up to 6 years except in participants attaining <0.01% MRD who continued treatment for the time taken to achieved MRD <0.01% and then stopped if MRD remained <0.01%. Month (M) 24 was earliest permitted stopping point. MRD flow cytometry was performed according to ERIC guidelines (panel: CD19/5/20/43/79/81+ROR1, acquisition of 0.5-2.2 million cells, BD Biosciences Lyric). Additional analysis of normal B-cell subsets was performed in a cohort of >500 patients (panel: CD19 to identify B-cells, CD20/5/79b+ROR1 and CD3 to exclude CLL & contaminating cells, with CD27/ 38/IgD/IgM to characterise normal B-cell subsets using a Coulter Cytoflex LX). Results: Normal B-cells were undetectable during FCR treatment and only rarely detectable until 12 months after last FCR cycle. Circulating normal B-cells were reduced in number or undetectable in participants receiving ibrutinibcontaining regimens with greater depletion in the I+V and IR arms relative to I monotherapy. B-progenitors persist through FCR treatment but were depleted during I, I+R or I+V treatment. Normal B-cell levels at 24 and 36 months after randomisation, with time off-treatment if applicable, are shown in Figure 1. In the ibrutinib-containing arms (IR, I, and I+V), there was a trend towards fewer COVID-associated SAE at any time point for participants with detectable B-cells at 24M (4/181, 2.2%) compared to those with no detectable B-cells (14/344, 4.1%) and COVID-associated SAEs were not observed in FCR-treated participants who had recovered any level of normal B-cells by 24M (0/215). However, the data on COVID infections are limited and there was no apparent association between normal B-cell levels at 24M with the proportion of participants experiencing an infectious SAE overall. Assessment of normal B-cell subsets during ibrutinib-based treatment demonstrated a mix of naïve and memory B-cells. Serological response to COVID infection/vaccination in this cohort is currently being performed. Participants stopping I+V treatment at 24-30 months post-randomisation due to MRD eradication showed rapid recovery of normal naive B-cells within 6-12 months after end of treatment in the vast majority (>95%) of evaluable cases. Summary/Conclusion: Normal circulating B-cells are depleted during treatment with rituximab but can persist at a low level during I, IR or I+V treatment. Most patients in remission after treatment with FCR or I+V show recovery of normal B-cells at 12 months of stopping treatment.
ABSTRACT
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 ;Munir et al.). Neither of the sudden deaths in the FCR arm ad 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. [Formula presented] 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.
ABSTRACT
Background: Pegcetacoplan (PEG), a PEGylated peptide targeting proximal complement protein C3, can control both intravascular and extravascular hemolysis. In the PEGASUS trial (NCT03500549), a phase 3, randomized, open-label, active-comparator controlled study, PEG was shown to be superior to eculizumab (ECU) after 16 weeks in improving hemoglobin levels (Hb) and clinical outcomes in patients with paroxysmal nocturnal hemoglobinuria (PNH) (Hillmen P et al, EHA 2020). Aims: We report on the efficacy and safety of PEG through 48 weeks of treatment. Methods: This study is a continuation of the PEGASUS trial. Eighty patients ≥18 years with PNH, and Hb levels <10.5 g/dL despite stable ECU treatment for ≥3 months, were enrolled. Patients completed a 4-week run-in period with both ECU and PEG before 1:1 randomization to PEG (n=41;1080 mg subcutaneously twice weekly) or ECU monotherapy (n=39;continued dosing regimen). The primary endpoint was the change from baseline (CFB) in Hb levels to Week 16. After the randomized control period (RCP), patients could continue to an open-label period (OLP), which included a 4-week run-in period for ECU patients (ECU-to-PEG), followed by PEG monotherapy (same dosage as in RCP) for all patients for a 48-week total study period. Key secondary endpoints included blood transfusion avoidance, CFB in absolute reticulocyte count (ARC), CFB in lactate dehydrogenase (LDH), CFB in Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue score, and adverse events (AEs). Results: Three patients discontinued PEG during the 16-Week RCP due to hemolysis;the remaining 77 patients entered the OLP. PEG demonstrated superiority to ECU with a mean Hb level improvement of 2.7 g/dL at Week 16, which was sustained throughout the OLP in all patients receiving PEG monotherapy. ECU-to-PEG patients demonstrated Hb improvement with mean Hb levels of 11.6 g/dL at Week 48 (CFB: 2.9 g/dL), while PEG-to-PEG patients maintained high Hb levels through the OLP with a mean Hb level of 11.3 g/dL at Week 48 (CFB: 2.6 g/dL) (Figure A). Seventy-three percent of PEG-to-PEG patients remained transfusion free for the 48-week study, and 72% of the ECU-to-PEG patients were transfusion free during the OLP through Week 48. Improvements in ARC (PEG-to- PEG: 80.0×109 cells/L;ECU-to-PEG: 94.0×109 cells/L), LDH (PEG-to-PEG: 222.7U/L;ECU-to-PEG: 224.1 U/L), and FACIT-fatigue score (PEG-to- PEG: 40.6;ECU-to-PEG: 42.5) were also observed at Week 48 (Figure B). The most common AEs by physician-reported preferred term throughout the study for all patients who received PEG were injection site reactions (36%), hemolysis (24%), and diarrhea (21%). Of all study patients, 30% experienced serious AEs with 6% possibly related to PEG. No cases of meningitis were reported. One death was reported due to COVID-19, unrelated to study treatment. Six patients discontinued due to hemolytic events: 5 classified by the treating physician as "hemolysis" and 1 as "hemolytic anemia." Overall, 12 patients (15%) discontinued PEG: 3 in RCP, 8 in OLP due to TEAEs (6 in ECU-to-PEG, 2 in PEG-to-PEG), and one during follow-up;one patient withdrew due to physician decision. Summary/Conclusion: Adult patients with PNH with suboptimal response on prior ECU treatment received PEG in this continuation of the PEGASUS trial and experienced durable treatment effect in all efficacy parameters at Week 48. The safety profile of PEG was consistent with previously reported data. The results suggest that PEG represents a new effective therapeutic option for patients with PNH.
ABSTRACT
Background: Pegcetacoplan (PEG), a PEGylated peptide targeting proximal complement protein C3, can control both intravascular and extravascular hemolysis. In the PEGASUS trial (NCT03500549), a phase 3, randomized, open-label, active-comparator controlled study, PEG was shown to be superior to eculizumab (ECU) after 16 weeks in improving hemoglobin (Hb) levels and clinical outcomes in patients with PNH (Hillmen P et al, EHA 2020). Aims: To identify if the prespecified strata (transfusion history and platelet count) of PEGASUS patients showed additional benefit from PEG vs ECU at 48 weeks. Methods: Eighty PNH patients (≥18 years) with Hb levels <10.5 g/ dL and ECU treatment (≥3 months) were enrolled. Patients entered a 4-week run-in period (RIP) with ECU+PEG (1080 mg subcutaneously 2x/week), then were stratified based on baseline platelet count and prior transfusion requirements, and randomized 1:1 to PEG or ECU monotherapy. The primary endpoint was change in Hb level from baseline to Week 16. Patients could continue to an open label period (OLP) of PEG monotherapy, which included a 4-week RIP (ECU+PEG) for ECU patients (ECU-to-PEG) but not for patients continuing PEG (PEG-to- PEG). Key secondary endpoints were transfusion avoidance and adverse events (AEs). Here, primary and key secondary endpoints were analyzed by subgroups (<4 vs ≥4 packed red blood cell transfusions within 12 months prior to baseline;platelet count at screening [<100,000x109/L vs ≥100,000x109/L]). Results: PEG treatment was associated with significantly greater increases in Hb levels from baseline than ECU at Week 16, which were maintained in the PEG-to-PEG arm through Week 48 regardless of baseline subgroup. The ECU-to-PEG arm demonstrated increased Hb levels regardless of prior transfusions (Figure A) or baseline platelet count (Figure B). At Week 48, Hb levels were similar in the <4 (mean [SD];PEG-to-PEG: 11.8 [1.9] g/dL;ECU-to-PEG: 11.8 [2.2] g/dL) and ≥4 transfusion strata (PEG-to-PEG: 10.9 [1.6] g/dL;ECU-to-PEG: 11.4 [2.2] g/dL). Similar Hb levels were also seen for the <100,000x109/L (PEG-to-PEG: 11.5 [2.2] g/dL;ECU-to-PEG: 12.7 [1.4] g/dL) and ≥100,000x109/L platelet strata (PEG-to-PEG: 11.2 [1.6] g/dL;ECU-to-PEG: 11.2 [2.3] g/dL). At Week 48, on PEG monotherapy, both arms had similar proportions of transfusion free patients during the OLP in the <4 (PEG-to-PEG: 80%;ECU-to-PEG: 88%) and ≥4 transfusion strata (PEG-to-PEG: 67%;ECUto- PEG: 61%). Similar trends were seen in the <100,000x109/L (PEGto- PEG: 75%;ECU-to-PEG: 78%) and ≥100,000x109/L platelet strata (PEG-to-PEG: 72%;ECU-to-PEG: 70%). The most common AEs by physician reported preferred term throughout the study for all patients who received PEG were injection site reactions (36%), hemolysis (24%), and diarrhea (21%). Of all study patients, 30% experienced serious AEs, 6% possibly related to PEG. No cases of meningitis were reported. One COVID-19 death was reported, unrelated to study treatment. Six patients discontinued due to hemolytic events: 5 classified by the treating physician as "hemolysis" and 1 as "hemolytic anemia." Overall, 12 patients (15%) discontinued PEG: 3 in RCP, 8 in OLP due to TEAEs (6 in ECU-to-PEG, 2 in PEG-to-PEG), and one during follow-up;one patient withdrew due to physician decision. Summary/Conclusion: In the prespecified stratified analysis of PEGASUS, PEG showed treatment effect durability in Hb level with transfusion avoidance in most PNH patients regardless of prior transfusions or baseline platelet count during the OLP through Week 48. The safety profile of PEG was consistent with previously reported data.
ABSTRACT
B-cell chronic lymphocytic leukaemia (CLL) is associated with immunosuppression and patients are at increased clinical risk following SARS-CoV-2 infection. Covid-19 vaccines offer the potential for protection against severe infection but relatively little is known regarding the profile of the antibody response following first or second vaccination. We studied spike-specific antibody responses following first and/or second Covid-19 vaccination in 299 patients with CLL compared with healthy donors. 286 patients underwent extended interval (10-12 week) vaccination. 154 patients received the BNT162b2 mRNA vaccine and 145 patients received ChAdOx1. Blood samples were taken either by venepuncture or as dried blood spots on filter paper. Spike-specific antibody responses were detectable in 34% of patients with CLL after one vaccine (n = 267) compared to 94% in healthy donors with antibody titres 104-fold lower in the patient group. Antibody responses increased to 75% after second vaccine (n = 55), compared to 100% in healthy donors, although titres remained lower. Multivariate analysis showed that current treatment with BTK inhibitors or IgA deficiency were independently associated with failure to generate an antibody response after the second vaccine. This work supports the need for optimisation of vaccination strategy in patients with CLL including the potential utility of booster vaccines.