Abstract: Idelalisib in combination with rituximab is an efficacious treatment for patients suffering from chronic lymphocytic leukemia (CLL) with known limitations due to toxicities. However, the benefit after prior Bruton tyrosine kinase inhibitor (BTKi) therapy remains unclear. For this analysis, 81 patients included in a non-interventional registry study of the German CLL study group (registered at www.clinicaltrials.gov as # NCT02863692) meeting the predefined criteria of a confirmed diagnosis of CLL and being treated with idelalisib containing regimens outside clinical trials were considered. 11 patients were treatment naïve (13.6%) and 70 patients (86.4%) pretreated. Patients had median of one prior therapy line (range 0–11). Median treatment duration with idelalisib was 5.1 months (range 0–55.0 months). Of 58 patients with documented treatment outcome, 39 responded to idelalisib containing therapy (67.2%). Patients treated with the BTKi ibrutinib as last prior treatment prior to idelalisib responded in 71.4% compared to a response rate of 61.9% in patients without prior ibrutinib. Median event free survival (EFS) was 15.9 months with a 16 versus 14 months EFS in patients with ibrutinib as last prior treatment or not, respectively. Median overall survival was 46.6 months. In conclusion, treatment with idelalisib appears to have a valuable impact in patients being refractory to prior ibrutinib therapy even though there are limitations in our analysis due to the low number of patients included.

Abstract: We report a randomized prospective phase 3 study (CLL7), designed to evaluate the efficacy of fludarabine, cyclophosphamide, and rituximab (FCR) in patients with an early-stage high-risk chronic lymphocytic leukemia (CLL). Eight hundred patients with untreated-stage Binet A disease were enrolled as intent-to-treat population and assessed for four prognostic markers: lymphocyte doubling time 〈 12 months, serum thymidine kinase 〉 10 U/L, unmutated IGHV genes, and unfavorable cytogenetics (del(11q)/del(17p)/trisomy 12). Two hundred and one patients with ≥2 risk features were classified as high-risk CLL and 1:1 randomized to receive either immediate therapy with 6xFCR (Hi-FCR, 100 patients), or to be observed according to standard of care (Hi-W & W, 101 patients). The overall response rate after early FCR was 92.7%. Common adverse events were hematological toxicities and infections (61.0%/41.5% of patients, respectively). After median observation time of 55.6 (0–99.2) months, event-free survival was significantly prolonged in Hi-FCR compared with Hi-W & W patients (median not reached vs. 18.5 months, p   〈  0.001). There was no significant overall survival benefit for high-risk patients receiving early FCR therapy (5-year OS 82.9% in Hi-FCR vs. 79.9% in Hi-W & W, p  = 0.864). In conclusion, although FCR is efficient to induce remissions in the Binet A high-risk CLL, our data do not provide evidence that alters the current standard of care “watch and wait” for these patients.

Abstract: Background: In early studies of venetoclax (ven) in CLL, severe tumor lysis syndromes (TLS) were observed leading to the implementation of multiple safety measures including a 5-week ramp up schedule. Since then, studies have consistently reported low rates of TLS in ven-treated patients (pts), most likely as a result of strict prophylactic and laboratory monitoring measures. Various lead-in regimens prior to the administration of ven were shown to be feasible and effective in reducing the risk of TLS in pts with CLL. However, no comparison of different pretreatment regimens has been performed so far in a prospective randomized trial. Using the set-up of the GAIA trial, we compared TLS incidence and formal TLS risk reduction between 3 different ven-based combinations. Methods: The phase 3 GAIA (CLL13) trial compared 3 different time-limited ven-based combinations against standard chemoimmunotherapy (CIT) in fit, treatment-naïve pts with CLL. Pts were randomized to receive CIT (FCR in pts ≤65 years; BR in pts & gt;65 years), ven and rituximab (RVe), ven and obinutuzumab (GVe), or ven, obinutuzumab and ibrutinib (GIVe). In RVe, GVe and GIVe, ven was added at cycle 1 day 22 (ramp up day 1) after a 21-day pretreatment with rituximab (1 dose), obinutuzumab (3 doses) or obinutuzumab (3 doses) plus ibrutinib (continuous) (Figure 1A). The safety population (i.e. all pts who received study treatment) of the ven-containing arms was used for this analysis. TLS was reported according to Cairo-Bishop criteria (Cairo M, Bishop M. Br J Haematol. 2004). For TLS risk evaluation, the most recent available CT/MRI and absolute lymphocyte count (ALC) were used. TLS risk was evaluated at baseline and at ramp up day 1, before the first dose of ven. The patients were categorized retrospectively according to the following TLS risk categories: high (any lymph node [LN] with largest diameter ≥10 cm or any LN with largest diameter ≥5 cm and ALC ≥25 G/L), intermediate (any LN ≥5 cm to & lt;10 cm or ALC ≥25 G/L), low (all LN & lt;5 cm and ALC & lt;25 G/L). Results: The safety population of all ven-containing arms comprised of 696 pts (RVe: 237, GVe: 228, GIVe: 231). Baseline TLS risk was high in 22%, 23% and 19% of pts in the RVe, GVe and GIVe arm, intermediate in 62%, 65%, 67% and low in 10.5%, 14.7% and 12.4% of pts, respectively. After the first 21 days of treatment (i.e. at ramp up day 1), the fraction of pts with a reduction in TLS risk varied between the treatment arms with 31.7% (RVe), 71.4% (GVe) and 47.3% (GIVe) of pts decreasing by at least one TLS risk category (Figure 1B). With regard to TLS risk reduction, GVe was superior to RVe (p & lt;0.001) and GIVe (p & lt;0.001) while GIVe was superior to RVe (p=0.001)). At ramp up day 1, 2 patients (1.0%) in the GVe arm versus 60 patients (29.6%) in the GIVe arm had an ALC ≥25 G/L, likely as a correlate of ibrutinib-associated redistribution of lymphocytes to the peripheral blood, readily explaining part of the difference in TLS risk reduction between GVe and GIVe. In total, 36, 30 and 19 cases of TLS occurred in 29 (12.2%), 26 (11.4%) and 19 (8.2%) pts in the RVe, GVe and GIVe arm. The majority of TLS cases were categorized as CTC grade 3 (28 [RVe], 19 [GVe] , 12 [GIVe]), only few CT C grade 4 TLS were reported (1 [RVe], 2 [GVe] , 3 [GIVe]). There were no cases of fatal TLS and no pts requiring dialysis due to TLS. In the obinutuzumab arms the majority of TLS cases occurred before ramp up day 1 (GVe: 76.7%, GIVe: 68.4%), i.e. before any venetoclax intake, in contrast 80.6% of TLS cases in the RVe arm were reported during ven ramp up (Figure 2). While there was no significant difference in the cumulative TLS incidence between the treatment arms (p=0.334), there was an increase in TLS occurring after ramp up day 1 in the RVe arm compared to GVe (p & lt;0.001) and GIVe (p=0.002). Conclusions: This analysis represents the first comparison of the formal TLS risk reduction and actual TLS incidence of different ven-based combinations in a randomized trial. GVe led to the highest TLS risk reduction, while the lowest number of TLS cases occurred in the GIVe arm. Most TLS cases in the GVe and GIVe arms occurred before the start of ven. RVe was least effective in reducing TLS risk and in contrast to the obinutuzumab-containing arms, the vast majority of TLS cases was reported during the ven ramp up. The relatively high incidence of TLS in comparison to other trials might partly be a consequence of using different reporting criteria (Cairo-Bishop vs Howard criteria). No fatal TLS occurred in any of the treatment arms. Figure 1 Figure 1. Disclosures Von Tresckow: AbbVie: Honoraria, Other: advisory board, travel grant; Celgene: Other: travel grant; AstraZeneca: Honoraria, Other; Roche: Honoraria, Other: Reasearch support, travel grant; Janssen: Honoraria, Other: Reasearch support, travel grant. Niemann: Novo Nordisk Foundation: Research Funding; CSL Behring, Genmab, Takeda, Octapharma: Consultancy; Abbvie, AstraZeneca, Janssen: Consultancy, Research Funding. Kater: Abbvie: Honoraria, Other: Ad Board, Research Funding; Janssen, AstraZeneca: Other: Ad Board, steering committee, Research Funding; Genmab, LAVA: Other: Ad Board, Steering Committee; BMS, Roche/Genentech: Other: Ad Board, , Research Funding. Staber: Roche: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; Takeda: Consultancy, Research Funding; MSD: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Incyte: Consultancy, Honoraria, Research Funding; Beigene: Consultancy, Honoraria. Tadmor: Janssen: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding. Levin: Roche, Janssen, Abbvie: Other: Travel Expenses, Ad-Board. Poulsen: Janssen: Consultancy; Abbvie: Consultancy. Janssens: Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Trael Grant, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy; Beigene, AstraZeneca: Consultancy, Speakers Bureau; Abbvie, Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Noesslinger: AbbVie: Honoraria; Celgene: Honoraria; Roche: Honoraria; Jansen: Honoraria; AstraZeneca: Honoraria; Gilead: Honoraria. Simon: Gilead: Other: Travel support. Fink: AbbVie: Other: travel grant; Janssen: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Research Funding; Celgene: Research Funding. Fischer: Abbvie: Honoraria; Roche: Honoraria, Other: Travel Grants. Wendtner: Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding; Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding; AstraZeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding; F. Hoffmann-LaRoche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding; Janssen Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding; Mundipharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding; Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support, Research Funding. Ritgen: MSD: Consultancy, Other: Travel support; Chugai: Consultancy; Abbvie: Consultancy, Other: Travel support, Research Funding; Roche: Consultancy, Other: Travel support, Research Funding; Celgene: Other: Travel support. Brüggemann: Amgen: Other: Advisory Board, Travel support, Research Funding, Speakers Bureau; Incyte: Other: Advisory Board; Janssen: Speakers Bureau. Stilgenbauer: AbbVie, Amgen, AstraZeneca, Celgene, Gilead, GSK, Hoffmann-La Roche, Janssen, Novartis, Sunesis: Honoraria; AbbVie, Amgen, AstraZeneca, Celgene, Gilead, GSK, Hoffmann-La Roche, Janssen, Novartis, Sunesis: Other: Research Support; AbbVie, Amgen, AstraZeneca, Celgene, Gilead, GSK, Hoffmann-La Roche, Janssen, Novartis, Sunesis: Research Funding; AbbVie, Amgen, AstraZeneca, Celgene, Gilead, GSK, Hoffmann-La Roche, Janssen, Novartis, Sunesis: Consultancy. Hallek: Roche: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Mundipharma: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Pharmacyclics: Honoraria, Speakers Bureau. Eichhorst: Gilead: Membership on an entity's Board of Directors or advisory committees, Other: Travel, accomodation, expenses, Research Funding, Speakers Bureau; F. Hoffmann-La Roche Ltd: Membership on an entity's Board of Directors or advisory committees, Other: Travel, accomodation, expenses, Research Funding, Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees, Other: Travel, accomodation, expenses, Research Funding, Speakers Bureau; BeiGene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Travel, accomodation, expenses, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Travel, accomodation, expenses, Speakers Bureau; Adaptive Biotechnologies: Speakers Bureau; Hexal: Speakers Bureau; ArQule: Membership on an entity's Board of Directors or advisory committees; Oxford Biomedica (UK): Membership on an entity's Board of Directors or advisory committees; MSD: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: Travel, accomodation, expenses, Research Funding, Speakers Bureau; Consultant Department I for Internal Medicine: Consultancy; University Hospital of Cologne: Current Employment. OffLabel Disclosure: The combination of obinutuzumab, venetoclax and ibrutinib is not approved for the treatment of CLL

Abstract: Despite considerable treatment advances with targeted therapies for patients with chronic lymphocytic leukemia (CLL) deemed high-risk [del(17p) and/or TP53 mutation], the outcome is still inferior compared with other CLL patients. Combining multiple agents with distinct mechanisms of action may further improve outcomes. CLL2-GIVe is an open-label, multicenter trial which enrolled patients with previously untreated CLL with del(17p) and/or TP53 mutation. Patients received induction therapy with obinutuzumab (GA-101), ibrutinib, and venetoclax (GIVe) for cycles 1 through 6 and consolidation therapy with venetoclax and ibrutinib for cycles 7 through 12. Ibrutinib monotherapy was continued for cycles 13 through 36 in patients not reaching a complete response (CR) with serial undetectable minimal residual disease (uMRD) after consolidation. The primary endpoint was CR rate at cycle 15 (final restaging). Secondary endpoints included MRD, survival, and safety. All 41 patients enrolled between September 2016 and August 2018 received study treatment and were included in efficacy and safety populations. With a CR rate of 58.5% at cycle 15, the primary endpoint was met (95% CI: 42.1-73.7; P & lt; .001). At final restaging, 78.0% of patients had uMRD in peripheral blood (PB); 65.9% of patients had uMRD in bone marrow (BM). Estimated progression-free survival (PFS) and overall survival (OS) rates at 24 months were both 95.1%. Adverse events were reported in all patients; most were low grade (grade ≥3: 23.9%). Two deaths were reported (cardiac failure and ovarian carcinoma), neither related to study treatment. The CLL2-GIVe treatment regimen has a manageable safety profile and is a first-line treatment of good efficacy for patients with high-risk CLL.

Abstract: Bruton tyrosine kinase (BTK) inhibitors are highly active drugs for the treatment of chronic lymphocytic leukemia (CLL). To understand the response to BTK inhibitors on a molecular level, we performed (phospho)proteomic analyses under ibrutinib treatment. We identified 3466 proteins and 9184 phosphopeptides (representing 2854 proteins) in CLL cells exhibiting a physiological ratio of phosphorylated serines (pS), threonines (pT), and tyrosines (pY) (pS:pT:pY). Expression of 83 proteins differed between unmutated immunoglobulin heavy-chain variable region (IGHV) CLL (UM-CLL) and mutated IGHV CLL (M-CLL). Strikingly, UM-CLL cells showed higher basal phosphorylation levels than M-CLL samples. Effects of ibrutinib on protein phosphorylation levels were stronger in UM-CLL, especially on phosphorylated tyrosines. The differentially regulated phosphopeptides and proteins clustered in pathways regulating cell migration, motility, cytoskeleton composition, and survival. One protein, myristoylated alanine-rich C-kinase substrate (MARCKS), showed striking differences in expression and phosphorylation level in UM-CLL vs M-CLL. MARCKS sequesters phosphatidylinositol-4,5-bisphosphate, thereby affecting central signaling pathways and clustering of the B-cell receptor (BCR). Genetically induced loss of MARCKS significantly increased AKT signaling and migratory capacity. CD40L stimulation increased expression of MARCKS. BCR stimulation induced phosphorylation of MARCKS, which was reduced by BTK inhibitors. In line with our in vitro findings, low MARCKS expression is associated with significantly higher treatment-induced leukocytosis and more pronounced decrease of nodal disease in patients with CLL treated with acalabrutinib.

Abstract: Fifty-one of 189 evaluable patients from 3 prospective phase 2 trials evaluating a sequential targeted treatment had high-risk chronic lymphocytic leukemia (CLL) with a 17p deletion, TP53 mutation, or both. Twenty-seven patients started treatment with bendamustine debulking before induction and maintenance treatment, which was ibrutinib/ofatumumab (IO) in 21 patients, ibrutinib/obinutuzumab (IG) in 13, and venetoclax/obinutuzumab (AG) in 17. The primary end point was overall response rate after 8 months of induction treatment, which was 81%, 100%, and 94% for IO, IG, and AG, respectively. Minimal residual disease (MRD) was undetectable (uMRD) in peripheral blood ( & lt;10−4 by flow cytometry) in 0%, 23%, and 82% of patients, respectively. Median progression-free survival (PFS) was 45 months. Seventeen patients discontinued maintenance treatment due to uMRD: 9 progressed, 2 died without progression (median PFS, 28 months after discontinuation of treatment), and 6 remained in remission after a median observation time of 46 months (range, 6-47 months) after treatment discontinuation. Thus, MRD-guided fixed-duration therapies combining obinutuzumab with venetoclax or ibrutinib can induce deep and durable remissions in CLL patients with high-risk genetic lesions, which can persist after treatment discontinuation (due to a predefined fixed-duration or MRD-guided early termination). The median PFS was 45 months. These trials were registered at www.clinicaltrials.gov as #NCT02345863, #NCT02401503, and #NCT02689141.