Kwak, Larry W.

Introduction: Standard of care for patients (pts) with relapsed or refractory (RR) Hodgkin lymphoma (HL) is salvage therapy (tx) followed by autologous hematopoietic cell transplantation (HCT). However, most pts with high-risk RR HL will relapse after HCT. The AETHERA study demonstrated that post-HCT consolidation with brentuximab vedotin (BV) in high-risk HL pts improved progression-free survival (PFS) compared to placebo, particularly in pts with 2+ risk factors (Moskowitz, 2018). Pts with prior BV exposure were excluded from AETHERA, and BV is increasingly used prior to HCT in HL. PD1 blockade is effective in pts with RR HL and PD1 monotherapy as post-HCT consolidation in HL resulted in promising 18 mo PFS (Armand, 2019). Combined BV and nivolumab (Nivo) is a safe and effective salvage tx in HL, therefore we conducted a multicenter phase 2 study to evaluate the safety and efficacy of BV-Nivo post-HCT consolidation in high risk RR HL. Methods: After HCT, adult pts with high-risk HL defined as having ≥ 1 of the following modified AETHERA risk factors were eligible: primary refractory HL, relapse < 1 year of completing initial tx, extranodal disease (dz) at relapse, B symptoms (sx) at relapse, requiring > 1 salvage tx, not in CR at HCT. Prior BV or PD1 blockade were allowed if pts were not refractory. Pts underwent HCT according to institutional standards at the 5 centers. Starting between day 30-75 after HCT, pts received 1.8 mg/kg of BV and 3mg/kg nivo q21 days for a planned 8 cycles. If 1 drug was discontinued due to toxicity, the other could be continued. Investigators assessed response and progressive disease (PD) according to the 2014 Lugano classification. The primary endpoint was 18 mo PFS from study tx initiation. Secondary endpoints were overall survival (OS), safety, and the response rate in pts not in complete response (CR) at baseline. Results: 59 pts were enrolled and treated with at least one dose of study tx. Baseline characteristics are listed in Table 1. 18 (31%) pts were primary refractory, 35 (59%) had early relapse, 23 (39%) had extranodal dz and 14 (24%) had B sx at relapse, 15 (25%) received > 1 salvage tx before HCT, and 48 (81%) were in CR at HCT. 21 (36%) had 1 modified AETHERA risk factor, 23 (40%) had 2 and 14 (24%) had 3+ risk factors. The median follow-up time from study tx initiation was 15.7 months (range, 2.8-35.5). Patients initiated BV-nivo a median 54 days from HCT (range, 34-75) and received a median of 8 cycles (range, 1-8). 29 (49%) pts completed all 8 cycles of BV and nivo and 45 (76%) patients completed 8 cycles of one drug. 14 (24%) pts discontinued both BV and nivo early, including 6 for adverse events (AE), 6 pt withdrawals, 1 pt lost to follow-up, and 1 pt death from PJP pneumonia unrelated to study tx. BV was discontinued in 8 (14%) pts - due to grade (gr) 3 peripheral neuropathy (PN) in 2 pts, gr 2 PN in 2 pts, carpal tunnel syndrome in 1 pt, gastrointestinal AEs in 2 pts, and infusion related reaction in 1 pt. Nivo was discontinued in 7 (12%) pts - due to pneumonitis in 2 pts, and colitis, elevated bilirubin, abnormal transaminases, pneumonia with elevated creatinine, and hypotension with fever in 1 pt each. BV was dose reduced to 1.2mg/kg in 11 (19%) pts, 9 pts for PN, and 1 each for neutropenia and arthralgia. The most common AEs related to BV-Nivo consolidation were PN (51%, 3% gr 3), neutropenia (42%, 31% gr 3-4), fatigue (37%), diarrhea (29%, 3% gr 3), nausea (25%, 2% gr 3), arthralgia (24%), AST elevation (24%, 2% gr 3). The most frequent gr 3-4 AEs were neutropenia (31%), pneumonitis (7%), and ALT elevation (5%). Immune-related (ir) AEs requiring systemic corticosteroids occurred in 18 (31%) patients. Most common Gr 2 or higher irAEs included: pneumonitis (12%), AST or ALT elevation (8%), hypothyroidism (5%), and rash (3%). 6 pts were not in CR at baseline after HCT (all PR). 5 pts converted to CR with study tx and 1 pt remained in PR without PD. There were only 2 PFS events, 1 pt with relapse at 15 months and PJP-related death after prophylaxis was self-discontinued. The estimated 18 mo PFS and OS in all patients were 95% and 98%, respectively. The estimated 18 mo PFS in pts with 2+ and 3+ risk factors were 92% and 89%, respectively. Conclusions: Post-HCT consolidation with BV-Nivo in pts with high-risk RR HL is a promising approach, with only 1 relapse observed in our cohort with short follow-up thus far. Post-HCT BV-Nivo was tolerable, though IrAEs were observed more frequently than in the pre-HCT setting and PN and neutropenia were common. Disclosures Herrera: Pharmacyclics: Research Funding; Karyopharm: Consultancy; AstraZeneca: Research Funding; Gilead Sciences: Consultancy, Research Funding; Immune Design: Research Funding; Seattle Genetics: Consultancy, Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Merck: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Other: Travel, Accomodations, Expenses, Research Funding. Nieto:Affimed: Consultancy, Other: Grant Support; Secura Bio: Other: Grant Support; Novartis: Other: Grant Support; Astra Zeneca: Other: Grant Support. Holmberg:Sanofi: Research Funding; Seattle Genetics: Research Funding; Millenium-Takeda: Research Funding; Bristol-Myers Squibb: Research Funding; UpToDate: Patents & Royalties: Royalties; Janssen: Research Funding; Merck: Research Funding. Mei:Sanofi: Consultancy; Morphosys: Membership on an entity's Board of Directors or advisory committees. Chen:Autolus Therapeutics: Current Employment. Rosen:Abbvie: Speakers Bureau; Seattle Genetics: Consultancy; NeoGenomics: Consultancy; Aileron Therapeutics: Consultancy; Novartis: Consultancy; Pebromene: Consultancy; Celgene: Speakers Bureau; paradigm Medical Communications: Speakers Bureau. Kwak:CJ Healthcare: Consultancy; Xeme Biopharma/Theratest: Other: equity; Sellas Life Sciences Grp: Consultancy; Enzychem Life Sciences: Membership on an entity's Board of Directors or advisory committees; Antigenics: Other: equity; InnoLifes, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pepromene Bio: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celltrion Healthcare: Membership on an entity's Board of Directors or advisory committees; Celltrion, Inc.: Consultancy. Feldman:Portola: Research Funding; Pfizer: Research Funding; Kyowa Kirin: Consultancy, Research Funding; Eisai: Research Funding; Cell Medica: Research Funding; Amgen: Research Funding; Pharmacyclics: Honoraria, Other, Speakers Bureau; Abbvie: Honoraria; Bayer: Consultancy, Honoraria; Trillium: Research Funding; Janssen: Speakers Bureau; Viracta: Research Funding; Rhizen: Research Funding; Corvus: Research Funding; BMS: Consultancy, Honoraria, Research Funding; Kite: Honoraria, Other: Travel expenses, Speakers Bureau; Celgene: Honoraria, Research Funding; Takeda: Honoraria, Other: Travel expenses; Seattle Genetics, Inc.: Consultancy, Honoraria, Other: Travel expenses, Research Funding, Speakers Bureau; AstraZeneca: Consultancy. OffLabel Disclosure: Nivolumab is not FDA-approved for use as consolidation after autologous stem cell transplantation

Abstract Studying gene expression and clinical outcome data from 136 clinical trials for patients with cancer (~21,000 patients with 26 cancer types), we found CD25 as one of the strongest predictors of poor clinical outcome in patients with B-cell malignancies, but not in other cancer types. This was unexpected because CD25 is known as one of three chains of the IL2 receptor on T-cells and NK-cells. Interleukin-2 (IL2) functions as essential T-cell growth factor. IL2 signals through β- and γ-, but not α-chains (CD25) of its heterotrimeric receptor. CD25-deficiency causes lymphoproliferation and autoimmunity, however, its mechanistic role is unclear. Our experiments based on genetic mouse models and engineered patient-derived B-cell leukemia and lymphoma xenografts revealed that CD25 expressed on B-cells is not an IL2 receptor chain, but in fact binds the B-cell receptor (BCR) to regulate its activity. Suggesting IL2-independent functions, defects in CD25-/-B-cells were not replicated in IL2-deficient mice. CD25 bound the BCR but not IL2Rβ- and IL2Rγ-chains. IL2Rβ- and IL2Rγ-chains can pair with other chains to form receptors for different cytokine-ligands. However, CD25 represents the first example of a cytokine receptor chain that binds to the BCR for negative feedback regulation. Likewise, in T-cells, CD25 had a bifunctional role and either functioned as IL2 receptor chain or as negative feedback regulator of T-cell receptor signaling. CD25-function was regulated by cell-membrane translocation, which required phosphorylation of its cytoplasmic tail at S268 (see schematic, left). In a family with monogenic autoimmunity, a mutation immediately preceding S268 compromised CD25-surface translocation, which was restored by homology-directed repair of the S268 motif. CD25-interactome analyses identified PKCd as critical effector molecule downstream of CD25 to mediate B-cell selection during normal B-cell development and calibrate oncogenic BCR signaling in B-cell tumors. In B-cell malignancies, BCR-dependent survival and proliferation signals are often substituted by oncogenic BCR-mimics (e.g. BCR-ABL1, JAK2, BRAFV600E, LMP2A, CD79B mutations; see schematic, right). Accordingly, we identified CD25 surface-expression as biomarker of oncogenic BCR-signaling and predictor of poor clinical outcomes. CD25-/-B-cell leukemia failed to initiate fatal disease in transplant recipients. Owing to imbalances of oncogenic BCR-signaling and p53-checkpoint activation, CD25-/- B-cell leukemia failed to initiate fatal disease in transplant recipients. In patient-derived xenograft models of drug-resistant B-cell malignancies, treatment with a CD25-specific antibody drug-conjugate (ADCT-301) extended survival of transplant recipients or eradicated disease. These findings identified CD25 as previously unrecognized feedback regulator of oncogenic BCR-signaling and provide a rationale for therapeutic targeting of CD25 in refractory B-cell malignancies. Figure. Figure. Disclosures Forman: Mustang Therapeutics: Other: Licensing Agreement, Patents & Royalties, Research Funding. Weinstock:Genentech/Roche, Monsanto: Consultancy; Novartis: Consultancy, Research Funding; Novartis, Astra Zeneca, Abbvie, Aileron, Surface Oncology, Daiichi Sankyo: Research Funding; Novartis, Dragonfly, Travera, DxTerity, Travera: Consultancy; Travera: Equity Ownership; Astra Zeneca, JAX, Samumed, Regeneron, Sun Pharma, Prescient: Patents & Royalties. Uzel:Novartis: Research Funding.

Abstract Abstract 3650 Background: Mantle cell lymphoma (MCL) is an aggressive lymphoma with poor prognosis. Cyclin D1 (CCND1) gene amplification is a marker of MCL. Glutathione (GSH) S-transferase pi (GSTP1) is a gene on the same amplicon as CCND1. Alternative splicing of CCND1 is mediated by an A/G single nucleotide polymorphism (SNP) in the exon 4 splice donor region. Inhibition of GSTP1 activity increased the sensitivity of MCL cell lines to cisplatin, cytarabine and bortezomib, but not doxorubicin suggesting its importance for drug resistance (Paret et al, 2005, ASH Abst #2806). Other GSH-related proteins were hypothesized to potentially be predictive biomarkers. We retrospectively analyzed DNA samples from MCL patients in a clinical trial with uniform first line chemoimmunotherapy treatment in order to study potential prognostic and predictive molecular markers including: GST M1/T1 gene copy number as well as SNPs for CCND1, GSTP1 and other GSH metabolism family of genes (described in Moyer et al, 2010 CEBP). Methods: DNA was available from 89 MCL patients treated with R-HyperCVAD from 1999 to 2002 at MD Anderson Cancer Center (MDACC). The CCND1 exon 4 (codon 242) SNP was evaluated using pyrosequencing. GST copy numbers were determined as previously described (Moyer et al., 2007 CCR). GSH-related gene SNP testing was performed at the Mayo Clinic Advanced Genomic Technology Center using an Illumina Golden Gate 384 plex panel [290 GSH-related SNPs (30 genes) and 94 additional SNPs in DNA damage repair and other pathways (19 genes] for GSTs and related GSH metabolism genes including GSH synthetase and GSH transporters. Comparison to ten year clinical data with an 8 year median follow-up was used under an IRB approved protocol (Romaguera et al., 2010, Br J Haematol). For overall survival (OS) and failure free survival (FFS), each SNP was first examined by the method of Kaplan and Meier and the log-rank test. To account for multiple testing (of 300+ SNP), we used a beta-uniform mixture model to model the sets of p-values for OS and FFS separately. SNPs that had a false discovery rate (FDR) adjusted p-value of less than 0.2 were evaluated with Cox proportional hazard models to examine the association between SNP and time to event. When there was evidence of non-proportional hazards, we fitted Bayesian parametric accelerated failure regression model. All tests are two-sided. All analyses were done using SAS (v 9.1, Cary, NC) and the R statistical project (http://www.r-project.org/). Results: Fifteen SNPs were significantly associated with FFS or OS in univariable analysis using a FDR q-value cut off of 0.2 (Table). Ten of these SNPs remained significant with FFS or OS after adjustment for age. Prognostic SNPs included GST (GSTO1, GSTO2, GSTA5) and DNA repair (LIG1, ERCC2, RAD52) genes. GST M1/T1 gene copy numbers and SNPs for GSTP1 and CCND1 were not found to be significantly associated with FFS and OS. Conclusion: DNA repair and GSH-associated gene SNPs correlated with OS and FFS in MCL patients treated with R-HyperCVAD at ten years follow-up. This is the largest MCL molecular marker study of which we are aware in a uniformly treated patient group and includes over 300 SNPs including CCND1, GSTP1, and GSH-associated metabolism pathway genes. Additional clinical trials may look at these SNPs in correlative studies. Statistically Significant SNPs Disclosures: No relevant conflicts of interest to declare.