Ansell, Stephen M.

Abstract Patients with relapsed/refractory (R/R) classical Hodgkin lymphoma (cHL) for whom autologous hematopoietic cell transplantation (auto-HCT) had failed experienced frequent and durable responses to nivolumab in the phase 2 CheckMate 205 trial. We present updated results (median follow-up, ∼5 years). Patients with R/R cHL who were brentuximab vedotin (BV)–naive (cohort A), received BV after auto-HCT (cohort B), or received BV before and/or after auto-HCT (cohort C) were administered with nivolumab 3 mg/kg IV every 2 weeks until progression or unacceptable toxicity. Patients in cohort C with complete remission (CR) for 1 year could discontinue nivolumab and resume upon relapse. Among 243 patients (cohort A, n = 63; B, n = 80; and C, n = 100), the objective response rate (ORR) was 71.2% (95% confidence interval [CI], 65.1-76.8); the CR rate was 21.4% (95% CI, 16.4-27.1). Median duration of response, CR, and partial remission were 18.2 (95% CI, 14.7-26.1), 30.3, and 13.5 months, respectively. Median progression-free survival was 15.1 months (95% CI, 11.3-18.5). Median overall survival (OS) was not reached; OS at 5 years was 71.4% (95% CI, 64.8-77.1). In cohort C, all 3 patients who discontinued in CR and were subsequently re-treated achieved objective response. No new or unexpected safety signals were identified. This 5-year follow-up of CheckMate 205 demonstrated favorable OS and confirmed efficacy and safety of nivolumab in R/R cHL after auto-HCT failure. Results suggest patients may discontinue treatment after persistent CR and reinitiate upon progression. This trial was registered at www.clinicaltrials.gov as #NCT02181713.

Abstract Lymphoma is the sixth most commonly diagnosed cancer in the US. Genome-wide association studies have identified common variants associated with risk of specific lymphoma subtypes, but less is known about the contribution of rare inherited variants in the genetic architecture of lymphoma risk. CHEK2 is important to DNA repair and 2 small studies have found evidence of an association between CHEK2 variants and risk of lymphoma. Here, we investigated loss of function (LoF) variants in CHEK2 with risk of lymphoma (overall and subtypes). The study population included newly diagnosed lymphoma cases from Mayo who were enrolled in the Lymphoma SPORE Molecular Epidemiology Resource (MER). Controls were from the Mayo Clinic Biobank, from which we excluded a prior hematologic malignancy. Whole exome sequencing was performed by Regeneron on an Illumina NovaSeq panel (mean coverage of 48X). Variants were called using GATK v4 and variant annotation was performed using BioR. All LoF variants (nonsense, frameshift and consensus splice sites) in CHEK2 with a minor allele frequency < 0.5% were included in the analyses. Logistic regression was used to estimate odds ratio (OR) and 95% confidence intervals (CI) for the association between CHEK2mutation status and risk of lymphoma overall, and by lymphoma subtypes that had more than 5 mutation carriers, which included diffuse large B-cell (DLBCL), follicular (FL), and T-cell lymphoma (TCL). All analyses were adjusted for age (at diagnosis for cases and at enrollment for controls) and sex. A total of 4,852 lymphoma cases and 49,724 controls were included in this analysis. Median age for both cases and controls was 62 years (range 18-99 years). Males accounted for 57.5% (n=2,789) of the cases and 40.6% (n=20,186) of the controls. The DLBCL (23.6% of cases) and FL (23.3% of cases) subtypes were the most common; 7.6% of cases had TCL. A total of 407 (0.7%) individuals had a LoF variant. The frequency of LoF variants was 1.2% in lymphoma cases and 0.7% in controls. LoF variants were associated with increased risk of lymphoma overall (OR=1.77; 95%CI: 1.32-2.33), DLBCL (OR=2.07; 95%CI: 1.20-3.13), and TCL (OR=2.78; 95%CI: 1.178-5.50), but not FL (OR=1.31; 95%CI: 0.65-2.34). CHEK2 c.1100delC was the most frequently mutated variant in this population, accounting for 76% of all LoF variants. Individuals with a c.1100delC variant had an increased risk of lymphoma overall (OR=1.90; 95%CI: 1.37-2.58), DLBCL (OR=2.06; 95%CI: 1.09-3.54), and TCL (OR=3.17; 95%CI:1.24-6.58), but not FL (OR=1.05; 95%CI: 0.41-2.15). When restricted to cases, there was no significant difference in age at diagnosis (P=0.62) or sex (P=0.53) between LoF variant carriers and non-carriers. In this large lymphoma case-control study, CHEK2 LoF variants were associated with increased risk of lymphoma, demonstrating that rare inherited variants may play an important role in the etiology of lymphoma. Additional work is needed to investigate missense variants in CHEK2 and risk of lymphoma. Citation Format: Nicholas J. Boddicker, Raphael Mwangi, Dennis P. Robinson, Allison C. Rosenthal, Thomas M. Habermann, Andrew L. Feldman, Lisa M. Rimsza, Rebecca L. King, Melissa C. Larson, Brianna J. Gysbers, Stephen M. Ansell, Jithma P. Abeykoon, Grzegorz S. Nowakowski, Thomas E. Witzig, Anne J. Novak, Susan L. Slager, James R. Cerhan. Germline CHEK2 variants and risk of lymphoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5233.