ASCO 2021: Abstract Recommendations From Dr. Isabel Cunningham for Hematologic Malignancies

Oral Abstract Session: Hematologic Malignancies—Leukemia, Myelodysplastic Syndromes, and Allotransplant
Friday, June 4, 2021; 2:30 PM–5:30 PM EDT

7001 Combination of ponatinib and blinatumomab in Philadelphia chromosome-positive acute lymphoblastic leukemia: Early results from a phase II study. NJ Short, HM Kantarjian, M Konopleva, et al

Take-Home Message

• The authors of this phase II study investigated the combination of ponatinib and blinatumomab in 28 adults with newly diagnosed or relapsed/refractory Ph+ positive acute lymphoblastic leukemia. Blinatumomab was given at standard doses up to five cycles, with ponatinib administered during the first cycle at 30 mg daily (decreased to 15 mg daily upon achievement of complete molecular remission [CMR]). In patients who responded, ponatinib was continued for 5 years or longer after blinatumomab was completed. Patients also received prophylactic intrathecal chemotherapy. All of the newly diagnosed patients and 88% of those with relapsed/refractory disease responded; of these, 87% in the newly diagnosed cohort and 86% in the relapsed/refractory cohort achieved CMR (median time to CMR was 1 month). For all patients, the estimated 1-year overall survival and event-free survival rates were 94% and 81%, respectively, at median follow-up of 14 months.

• The combination of ponatinib and blinatumomab was well-tolerated, with no early deaths (within 4 weeks) and with high rates of CMR. The results suggest that use of this combination may reduce the need for chemotherapy and allogeneic HSCT in patients with Ph+ acute lymphoblastic leukemia.

7004 Letermovir prophylaxis and cytomegalovirus reactivation in adult allogeneic hematopoietic cell transplant recipients with graft versus host disease. D Wolfe, Q Zhao, EG Siegel, et al

Take-Home Message

• In this single-center retrospective study, the authors evaluated the effectiveness of letermovir for reducing cytomegalovirus (CMV) infection after allogeneic HSCT in patients who develop graft-versus-host disease (GVHD) and continue letermovir therapy past day 100. Of 262 CMV-seropositive patients included in the study, 111 had been treated for clinically significant CMV infection; of these, 29 had received prophylactic letermovir. The use of letermovir was associated with a significantly lower incidence of CMV viremia in all patients and in patients with acute GVHD grade >2 within 200 days after transplant (P < .001 for both). Moreover, patients who received letermovir had lower non-relapse mortality and greater overall survival rates.

• Letermovir prophylaxis is effective for reducing clinically significant CMV infection and improving overall survival in this patient population. Continuing it past day 100 may be beneficial for those who develop acute GVHD.

7006 Effect of olutasidenib (FT-2102) on complete remissions in patients with relapsed/refractory (R/R) mIDH1 acute myeloid leukemia (AML): Results from a planned interim analysis of a phase 2 clinical trial. S De Botton, KWL Yee, C Recher, et al

Take-Home Message

• The authors present interim results of a phase II trial of the use of olutasidenib monotherapy (150 mg twice daily) in patients with relapsed/refractory mutant IDH1 acute myeloid leukemia. Of the 153 patients enrolled, 43 remain on olutasidenib and 110 discontinued treatment (most commonly because of disease progression, adverse events, or patient death); median duration of treatment was 5.5 months.

• The drug was well-tolerated, and all response groups achieved transfusion independence. Olutasidenib led to durable complete remission in a subset of high-risk patients.

7007 Efficacy and safety of aspacytarabine (BST-236) as a single-agent, first-line therapy for patients with acute myeloid leukemia unfit for standard chemotherapy. JK Altman, J Koprivnikar, JK McCloskey, et al

Take-Home Message

• This phase IIb open-label, single-arm study was designed to investigate the safety and efficacy of aspacytarabine, a prodrug of cytarabine, as first-line therapy for patients newly diagnosed with acute myeloid leukemia (AML) unfit for intensive chemotherapy. A total of 46 patients (median age, 75 years) completed one to four courses of aspacytarabine 4.5 g/m²/day. To date, 43 patients could be evaluated for efficacy analysis; of these, 15 achieved complete remission with hematologic recovery (median, 27.5 days) after one or two courses.

• The results thus far support the safety and efficacy of aspacytarabine as a first-line treatment for AML patients unsuited for standard chemotherapy.

Oral Abstract Session: Pediatric Oncology I
Saturday, June 5, 2021; 10:00 AM–1:00 PM EDT

10004 Minimal residual disease at end of induction and consolidation remain important prognostic indicators for newly diagnosed children and young adults with very high-risk (VHR) B-lymphoblastic leukemia (B-ALL): Children’s Oncology Group AALL1131. WL Salzer, MJ Burke, M Devidas, et al

Take-Home Message

• The authors sought to determine whether survival is improved among children and young adults with very high–risk B-acute lymphoblastic leukemia who are minimal residual disease (MRD)–positive at the end of induction (EOI) and become MRD-negative at the end of consolidation (EOC) compared with those who remain MRD-positive at EOC.

• Among 823 patients, 4-year disease-free survival was significantly improved in those who were MRD-positive at EOI and MRD-negative at EOC compared with those who remained MRD-positive. The authors conclude that MRD is a strong prognostic indicator in very high–risk B-acute lymphoblastic leukemia.

Oral Abstract Session: Hematologic Malignancies—Lymphoma and Chronic Lymphocytic Leukemia
Monday, June 7, 2021; 11:30 AM–2:30 PM EDT

7501 Fixed-duration (FD) first-line treatment (tx) with ibrutinib (I) plus venetoclax (V) for chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL): Primary analysis of the FD cohort of the phase 2 captivate study. P Ghia, JN Allan, T Siddiqi, et al

Take-Home Message

• The authors report results for the fixed-duration cohort of the CAPTIVATE trial of first-line ibrutinib plus venetoclax for chronic lymphocytic leukemia (CLL). A total of 159 patients (median age, 60 years) with previously untreated CLL/small lymphocytic lymphoma (SLL) underwent 3 cycles of ibrutinib followed by 12 cycles of ibrutinib plus venetoclax; 55% achieved complete response (CR), a rate that was consistent for high-risk subgroups. Of these patients, 89% had CR ≥1 year. The overall response rate was 96%; the 24-month progression-free survival was 95%; 24-month overall survival was 98%. Most adverse events were grade 1 or 2.

• These results suggest that first-line ibrutinib plus venetoclax can produce durable responses in patients with CLL/SLL, including those in high-risk subgroups, with a safety profile consistent with that for each drug.

7502 First-in-human study of lisaftoclax (APG-2575), a novel BCL-2 inhibitor (BCL-2i), in patients (pts) with relapsed/refractory (R/R) CLL and other hematologic malignancies (HMs). S Ailawadhi, AAA Chanan-Khan, Z Chen, et al

Take-Home Message

• The authors of this phase I study investigated the efficacy, safety, pharmacokinetics, pharmacodynamics, and maximum tolerated dose/recommended phase II dose of lisaftoclax, a novel, orally administered, small-molecule selective BCL-2 inhibitor. In all, 35 patients with relapsed/refractory chronic lymphocytic leukemia (CLL) or other hematologic malignancies were enrolled and received lisaftoclax daily in 28-day cycles at doses ranging from 20 mg to 1200 mg. The overall response rate was 85.7% for 12 of the 14 evaluable patients with relapsed/refractory CLL or small lymphocytic lymphoma, with a median of 3 cycles to response.

• The results indicate that lisaftoclax was well-tolerated. The maximum tolerated dose was not reached, and no tumor lysis syndrome occurred. Treatment-related adverse events greater than grade 2 were infrequent.