Assessment of the Efficacy of Therapies Following Venetoclax Discontinuation in CLL Reveals BTK Inhibition as an Effective Strategy.

PURPOSE: Venetoclax-based therapy is a standard-of-care option in first-line and relapsed/refractory chronic lymphocytic leukemia (CLL). Patient management following venetoclax discontinuation remains nonstandard and poorly understood. EXPERIMENTAL DESIGN: To address this, we conducted a large international study to identify a cohort of 326 patients who discontinued venetoclax and have been subsequently treated. Coprimary endpoints were overall response rate (ORR) and progression-free survival for the post-venetoclax treatments stratified by treatment type [Bruton's tyrosine kinase inhibitor (BTKi), PI3K inhibitor (PI3Ki), and cellular therapies]. RESULTS: We identified patients with CLL who discontinued venetoclax in the first-line (4%) and relapsed/refractory settings (96%). Patients received a median of three therapies prior to venetoclax; 40% were BTKi naïve (n = 130), and 81% were idelalisib naïve (n = 263). ORR to BTKi was 84% (n = 44) in BTKi-naïve patients versus 54% (n = 30) in BTKi-exposed patients. We demonstrate therapy selection following venetoclax requires prior novel agent exposure consideration and discontinuation reasons. CONCLUSIONS: For BTKi-naïve patients, selection of covalently binding BTKis results in high ORR and durable remissions. For BTKi-exposed patients, covalent BTK inhibition is not effective in the setting of BTKi resistance. PI3Kis following venetoclax do not appear to result in durable remissions. We conclude that BTKi in naïve or previously responsive patients and cellular therapies following venetoclax may be the most effective strategies.See related commentary by Rogers, p. 3501.

Assessment of Impact of HLA Type on Outcomes of Allogeneic Hematopoietic Stem Cell Transplantation for Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia (CLL) is a common hematologic malignancy with many highly effective therapies. Chemorefractory disease, often characterized by deletion of chromosome 17p, has historically been associated with very poor outcomes, leading to the application of allogeneic hematopoietic stem cell transplantation (allo-HCT) for medically fit patients. Although the use of allo-HCT has declined since the introduction of novel targeted therapy for the treatment of CLL, there remains significant interest in understanding factors that may influence the efficacy of allo-HCT, the only known curative treatment for CLL. The potential benefit of transplantation is most likely due to the presence of alloreactive donor T cells that mediate the graft-versus-leukemia (GVL) effect. The recognition of potentially tumor-specific antigens in the context of class I and II major histocompatibility complex on malignant B lymphocytes by donor T cells may be influenced by subtle differences in the highly polymorphic HLA locus. Given previous reports of specific HLA alleles impacting the incidence of CLL and the clinical outcomes of allo-HCT for CLL, we sought to study the overall survival and progression-free survival of a large cohort of patients with CLL who underwent allo-HCT from fully HLA-matched related and unrelated donors at Center for International Blood and Marrow Transplant Research transplantation centers. We found no statistically significant association of allo-HCT outcomes in CLL based on previously reported HLA combinations. Additional study is needed to further define the immunologic features that portend a more favorable GVL effect after allo-HCT for CLL.

Association of Socioeconomic Status with Outcomes of Autologous Hematopoietic Cell Transplantation for Multiple Myeloma.

Autologous hematopoietic cell transplantation (AHCT) is standard therapy for eligible patients with multiple myeloma. Health care disparities can influence transplantation outcomes. However, the association of socioeconomic status (SES), a major indicator of health care disparities, with outcomes in patients with myeloma after AHCT has not been previously described. We analyzed 346 consecutive AHCT recipients with myeloma who underwent transplantation between 2003 and 2013 in this retrospective cohort study. Zip code of residence at the time of AHCT was obtained to assess annual household income based on 2010 US census data (median, $49,054; range, $16,546 to $127,313). SES groups were divided into < $45,000 (low; n = 120), $45,000 to $60,000 (middle; n = 116), and > $60,000 (high; n = 110). The low-income cohort had smallest portion of Caucasians (69% versus 89% versus 91%); otherwise, patient, disease, and transplantation characteristics were comparable among cohorts or different without significant patterns found. Median follow-up was 49 months. There was no difference among SES groups in overall survival, progression-free survival, nonrelapse mortality, or relapse in univariate and multivariable analysis. Similarly, SES was not associated with survival in a subset analysis of 303 patients who had survived for 1 year after transplantation.