This is a phase II, single-arm, open-label, multicentre study of acalabrutinib and rituximab for elderly or frail patients with previously untreated mantle cell lymphoma.

This is a randomized Phase II study of intermittent versus continuous venetoclax therapy with Acalabrutinib in previously untreated Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL)

The purpose of this study is to test a combination treatment of acalabrutunib when given together with rituximab-ifosfamide-carboplatin-etoposide (R-ICE) to evaluate if it will be able to improve durable responses and cure some patients.

Background: Diffuse large B-cell lymphoma (DLBCL) subtypes have differential response to BTK inhibitors (BTKi). Ibrutinib with R-CHOP improves survival in DLBCL subsets, but toxicity is limiting. Precise characterization of BTKi-responsive tumors enhances pt selection. Acalabrutinib (acala) is a BTKi with activity in DLBCL, but the molecular correlates of acala response are unknown. Circulating tumor DNA (ctDNA) is a prognostic biomarker in DLBCL including early changes during chemotherapy. PhasED-Seq is a novel ctDNA method that lowers the error profile of mutation detection by requiring the concordant detection of two separate mutations on an individual cell-free DNA molecule (Kurtz et al. Nat Biotechnol 2021). We employed a response-adapted study of acala for up to 14d prior to frontline therapy for aggressive B-cell lymphoma to determine the molecular profile of BTKi-responsive tumors. We report preliminary results including dynamic changes in ctDNA from this ongoing trial [NCT04002947]. Methods: Pts with untreated aggressive B-cell lymphoma and any HIV status are eligible if age ≥18, ≥stage 2, PS ≤2, and adequate organ function. Pts with PMBL, unmeasurable lesions, or active CNS disease are excluded. Screening includes labs, CT and FDG-PET, BM, and CSF with flow cytometry. Pts first receive acala 100mg twice daily x 14d. Pts with <25% reduction in bi-dimensional lesions by CT after acala receive DA-EPOCH-R or R-CHOP for 4-6 cycles every 21d. Pts with ≥25% reduction on CT after the window continue acala 100mg twice daily on days 1-10 of each cycle of R-chemo. Tumors undergo multi-platform profiling including whole exome, RNA sequencing, and assessment of DNA copy number. Streck tubes are collected at baseline, after 7d of acala, end of acala, end of C2, end of therapy, and during surveillance. ctDNA levels were quantified using PhasED-Seq (Foresight Diagnostics Inc.) to track phased variants. Results: 34 pts enrolled between August 2019 and July 2021 and completed the acala window. Median age was 64 (range 28-85) including 13 (38%) < 60y, 14 (41%) 61-69, and 7 (21%) ≥70y. Three (9%) pts had HIV and 17 (50%) were high-risk by IPI. The median diagnosis to treatment was 22.5d (4-53). IHC subtypes by Hans included 17 (50%) non-GCB, 16 (47%) GCB, and 1 (3%) T-cell/histiocyte-rich large B-cell lymphoma (TRLBCL). Four (12%) pts were high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 (HGBL-DH). Fifteen (44%) pts responded to acala during the window, while 19 (56%) pts had no response (Figure 1A). Acala responses were seen across DLBCL subtypes including 7 (47%) pts with non-GCB, 7 (47%) pts with GCB, and 1 (7%) pt with TRLBCL. Twenty pts had RNA sequencing to confirm cell-of-origin including 10 responders which included 7 (70%) GCB, 2 (20%) ABC, and 1 (10%) Unclassified. Notably, 13 (86%) BTKi-responsive tumors were CD10 negative and only 2 (18%) CD10+ tumors were BTKi-responsive. ctDNA dynamics strongly correlated with CT response as the log-fold change in ctDNA (hGE/mL) at the end of the window correlated with change on CT (r=0.75, p=0.0013). Remarkably, ctDNA dynamics after only 7d also correlated with change on CT (r=0.82, p=0.00006)(Figure 1B-C). Interestingly, one pt had improved symptoms and a 20-fold drop in ctDNA, but no corresponding CT changes suggesting that ctDNA changes may precede CT changes in some cases. Twenty-nine (85%) pts completed all planned cycles of therapy while 5 pts stopped chemotherapy early due to myelosuppression (n=3), CHF (n=1), and MI (n=1). Toxicity across 156 cycles was mostly hematologic. G3/G4 neutropenia occurred in 50% and 38% of cycles and febrile neutropenia in 10% of cycles. G3/G4 thrombocytopenia occurred in 22% and 12% of cycles. No increase in infections, atrial fibrillation, or bleeding were observed in pts treated with acala. All 27 pts who completed therapy achieved a CR. Two pts (1 acala responder) have relapsed from CR and 1 pt died of an MI. After a median follow-up of 9.2m the estimated 1-year PFS was 84.9% (95% CI.: 58-95). Conclusions: Acalabrutinib prior to frontline therapy has activity in GCB, non-GCB, and

HGBL-DH:

confirmed by gene expression profiling. CD10+ GCB tumors are mostly acala-resistant. Toxicity is mainly hematologic and manageable across age groups including pts with HIV. ctDNA correlates with CT change and may predict response to targeted agents as early as 7 days. Updated clinical results within genetic subtypes will be presented at the meeting. [Formula presented] Disclosures: Chabon: Foresight Diagnostics: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Lurain: CTI Biopharma: Research Funding; EMD-Serrono: Research Funding; Merck: Research Funding; BMS-Celgene: Research Funding; Janssen: Research Funding. Bagaev: BostonGene Corp.: Current Employment, Current holder of stock options in a privately-held company, Patents & Royalties: BostonGene. Postovalova: BostonGene Corp.: Current Employment, Current holder of stock options in a privately-held company, Patents & Royalties: BostonGene. Meerson: BostonGene: Current Employment, Current holder of stock options in a privately-held company, Patents & Royalties: BostonGene. Kudryashova: BostonGene: Current Employment, Current holder of stock options in a privately-held company, Patents & Royalties: BostonGene. Kotlov: BostonGene Corp: Current Employment, Current holder of stock options in a privately-held company, Patents & Royalties. Fowler: BostonGene: Current Employment, Current holder of stock options in a privately-held company. Kurtz: Roche: Consultancy; Foresight Diagnostics: Consultancy, Current holder of stock options in a privately-held company; Genentech: Consultancy. Alizadeh: CAPP Medical: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Forty Seven: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Foresight Diagnostics: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Roche: Consultancy, Honoraria; Janssen Oncology: Honoraria; Celgene: Consultancy, Research Funding; Gilead: Consultancy; Bristol Myers Squibb: Research Funding; Cibermed: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company.

Background: Patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) often have a poor prognosis despite therapies using second-line chemoimmunotherapy. Achievement of CR with second-line therapy is associated with improved long-term outcomes. Unfortunately, only 25-35% of patients achieve complete response (CR) with RICE chemotherapy alone. The addition of novel targeted agents such as Bruton Tyrosine Kinase inhibitors (BTKi) to second-line therapy may offer improved treatment responses given the importance of B-cell receptor (BCR) signaling in DLBCL. BTK has been shown to be essential for BCR-mediated activation of the NF- κB/Rel family of transcription factors and BCR signaling has been recognized as a key pathway in the pathogenesis of DLBCL. Moreover, NF-κB activity relies upon chronic active BCR signaling in activated B-cell-like DLBCL, which can be potentially blocked by kinase inhibitors targeting BTK. The goal of this study is to examine the feasibility and efficacy of adding the BTKi, acalabrutinib, to standard second-line therapy as a means to improve disease response. Establishing the feasibility of combining acalabrutinib with RICE chemotherapy in autologous hematopoietic cell transplantation (HCT) eligible and HCT ineligible patients with R/R DLBCL may provide the foundation for a larger study of efficacy and long-term outcomes of the combination therapy for patients with R/R DLBCL. Study Design and Methods: The primary objective of this phase 2 trial is to evaluate the tolerability, feasibility, and efficacy of combining acalabrutinib with RICE as second line therapy in R/R DLBCL patients. There are two study cohorts. Cohort A is open to R/R DLBCL patients who are eligible for autologous HCT. Cohort B is open to R/R DLBCL patients who are considered medically ineligible for autologous HCT. The primary endpoint for cohort A is to estimate the confirmed CR rate (RECIL 2017 criteria) prior to HCT in patients undergoing second-line therapy. The primary endpoint for cohort B is defined as the estimate of one-year progression-free survival in patients undergoing second-line induction and maintenance acalabrutinib therapy. Secondary endpoints include assessment of the proportion of patients completing 3 cycles of acalabrutinib with RICE and proceeding with HCT or 2 additional cycles of maintenance acalabrutinib for HCT ineligible patients, overall response rate, incidence of Grade 3/4 adverse events, and incidence of SAEs. Patients in cohort A receive 2 cycles of standard RICE salvage chemoimmunotherapy in combination with acalabrutinib, 100mg BID day 1-21 of a 21 day cycle. After 2 cycles of therapy, patients in cohort A undergo autologous stem cell mobilization and collection. Patients then receive a 3rd cycle of RICE in combination with acalabrutinib. PET-CT (PET3) is performed 14-21 days after day 1 of cycle 3 to assess response. Those patients with CR or partial response (PR) after PET3 proceed to autologous HCT with BEAM conditioning within 28-42 days of PET3. After adequate hematopoietic recovery, patients restart acalabrutinib 100mg BID as maintenance therapy for a period of 12 additional months. Patients in cohort B receive 3 cycles of RICE salvage chemoimmunotherapy in combination with acalabrutinib 100mg BID day 1-21 of a 21-day cycle followed by PET-CT (PET3) 14-21 days after start of Cycle 3. Patients without progressive disease at PET3 continue with acalabrutinib maintenance up to 12 additional cycles until disease progression or unacceptable toxicity. Patients demonstrating progressive disease are withdrawn from study treatment but their outcomes continue to be recorded and will be included in the final data analysis. Historical outcomes from completed, published prospective clinical trials using RICE chemoimmunotherapy serve as a reference for statistical calculations. This trial is currently ongoing and additional information can be found on clinicaltrials.gov NCT listing NCT03736616 Disclosures: Bensinger:

BMS:

Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau;

GSK:

Consultancy, Honoraria, Research Funding, Speakers Bureau; Regeneron: Consultancy, Honoraria, Research Funding, Speakers Bureau. Mawad: Abbvie: Speakers Bureau; Adaptive Biotechnologies: Speakers Bureau. Glennie: Pharmacyclics: Speakers Bureau; Janssen: Speakers Bureau. Patel: Pharmacyclics: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Kite: Consultancy; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; Adaptive Biotechnologies: Consultancy; Genentech: Consultancy, Speakers Bureau; Celgene

/BMS:

Consultancy, Membership on an entity's Board of Directors or advisory committees; BeiGene: Consultancy. OffLabel Disclosure: Acalabrutinib is used an investigational agent for DLBCL in this study.

BACKGROUND:

Whether fixed-duration acalabrutinib-venetoclax (with or without obinutuzumab) would result in better progression-free survival than chemoimmunotherapy in patients with untreated chronic lymphocytic leukemia (CLL) is unknown.

METHODS:

In this phase 3, open-label trial, we included patients 18 years of age or older who had an Eastern Cooperative Oncology Group performance-status score of 0 to 2 (range, 0 to 5, with higher numbers indicating greater disability) and who did not have a 17p deletion or TP53 mutation. Patients were randomly assigned, in a 1:1:1 ratio, to receive acalabrutinib-venetoclax (acalabrutinib, cycles 1 to 14; venetoclax, cycles 3 to 14), acalabrutinib-venetoclax-obinutuzumab (as above, plus obinutuzumab, cycles 2 to 7), or chemoimmunotherapy with the investigator's choice of fludarabine-cyclophosphamide-rituximab or bendamustine-rituximab (cycles 1 to 6). The primary end point was progression-free survival (acalabrutinib-venetoclax vs. chemoimmunotherapy) in the intention-to-treat population, assessed by blinded independent central review.

RESULTS:

A total of 867 patients underwent randomization: 291 were assigned to receive acalabrutinib-venetoclax, 286 acalabrutinib-venetoclax-obinutuzumab, and 290 chemoimmunotherapy (of whom 143 received fludarabine-cyclophosphamide-rituximab and 147 bendamustine-rituximab). The median age of the patients was 61 years (range, 26 to 86), 64.5% were men, and 58.6% had unmutated IGHV. Estimated 36-month progression-free survival at a median follow-up of 40.8 months was 76.5% with acalabrutinib-venetoclax, 83.1% with acalabrutinib-venetoclax-obinutuzumab, and 66.5% with chemoimmunotherapy (hazard ratio for disease progression or death with acalabrutinib-venetoclax vs. chemoimmunotherapy, 0.65 [95% confidence interval {CI}, 0.49 to 0.87], P = 0.004; for the comparison of acalabrutinib-venetoclax-obinutuzumab with chemoimmunotherapy, P<0.001). Estimated 36-month overall survival was 94.1% with acalabrutinib-venetoclax, 87.7% with acalabrutinib-venetoclax-obinutuzumab, and 85.9% with chemoimmunotherapy. Neutropenia, the most common adverse event of clinical interest of grade 3 or higher, was reported in 32.3%, 46.1%, and 43.2% in the three groups, respectively; death from coronavirus disease 2019 was reported in 10, 25, and 21 patients in the three groups.

CONCLUSIONS:

Acalabrutinib-venetoclax with or without obinutuzumab significantly prolonged progression-free survival as compared with chemoimmunotherapy in fit patients with previously untreated CLL. (Funded by AstraZeneca; AMPLIFY ClinicalTrials.gov number, NCT03836261.).

This phase II trial studies the side effects of acalabrutinib and rituximab and its effect in treating patients with previously untreated mantle cell lymphoma. Acalabrutinib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Rituximab is a monoclonal antibody that binds to a protein called CD20, which is found on B-cells, and may kill cancer cells. Giving acalabrutinib and rituximab may help to control mantle cell lymphoma in elderly patients.

This is a multicenter, open-label, non-randomized, phase II clinical trial conducted in Canada. The purpose of the study is to determine the remission rate of acalabrutinib in combination with R-CHOP in patients with previously untreated mantle cell lymphoma prior to autologous stem cell transplantation. All patients will receive six cycles of R-CHOP chemotherapy together with continuous acalabrutinib at the standard dose twice per day orally. All patients will undergo response assessment at the end of six cycles of R-CHOP + acalabrutinib with CT scan, PET/CT scan, and bone marrow biopsy. Responding patients will proceed with stem cell mobilization, apheresis, and processing. Following ASCT, patients will receive standard maintenance rituximab every 3 months for 2 years.

This study is evaluating the safety, pharmacodynamics (PD), and efficacy of acalabrutinib and pembrolizumab in hematologic malignancies.

A Phase 1b, Multicenter, Open-label Study of Acalabrutinib in Combination with Bendamustine and Rituximab (BR) or Venetoclax and Rituximab (VR) in Subjects with Mantle Cell Lymphoma