Amengual, Jennifer E.

Abstract The phase 1/2 Intergroup study E4412 investigated checkpoint blockade with nivolumab (Nivo) and ipilimumab (Ipi) combined with the CD30 targeting antibody-drug conjugate brentuximab vedotin (BV) in relapsed/refractory classic Hodgkin lymphoma. A total of 147 patients aged ≥12 years were randomized between BV/Nivo and BV/Ipi/Nivo; 132 patients were included in the primary efficacy analysis. The complete response (CR) rate, was 64.7% (52.2, 75.9) for BV/Nivo and 70.3% (57.6, 81.1) for BV/Ipi/Nivo (1-sided P = .29). The median survival follow-up was 38.0 months (interquartile range, 32.6-48.1). Progression-free survival (PFS) did not significantly differ between the 2 arms (hazard ratio [HR], 0.78, confidence interval [CI], 0.39-1.57; 1-sided P = .24). Treatment-related grade 3+ toxicities in the adult cohort, excluding rash, were similar between both arms (38.5% BV/Nivo and 39.3% BV/Ipi/Nivo); there was a higher frequency of grade 3 rash with BV/Ipi/Nivo (24.6%) compared with BV/Nivo (9.2%). We compared PFS by stem cell transplantation (SCT) status in a planned before hoc comparison; 58 patients received SCT, and 36-month PFS (from SCT) was >90% for both arms. Sixty-six patients were progression free after the first scan and did not undergo SCT. The 36-month PFS was 73.0% (54.5, 85.0) for BV/Ipi/Nivo compared with 45.8% (26.3, 63.4) for BV/Nivo (HR, 0.45; CI, 0.19-1.08; 1-sided P = .03). The study did not meet its primary end point of superior CR rate for the triplet, but it supports the use of checkpoint antibody-drug conjugate induction prior to auto SCT, and there is an intriguing signal of disease control for patients wishing to defer or avoid SCT with the triplet of BV/Ipi/Nivo. This trial was registered at www.clinicaltrials.gov as NCT01896999.

Abstract Germinal center B-cell lymphomas frequently exhibit monoallelic loss-of-function mutations in the histone acetyltransferases CREBBP and p300, which contribute to lymphoma development, disrupt normal germinal center biology, and promote immune evasion. This study evaluates YF2, a histone acetyltransferase activator that increases CREBBP/p300 activity, as a potential therapeutic approach for B-cell lymphoma. YF2 binds the bromodomain of CREBBP/p300, increasing their auto-acetylation and enzymatic activity. It also induces cytotoxicity in B-cell lymphoma cell lines, with a stronger response in those carrying CREBBP / EP300 mutations. Additionally, YF2 increases the acetylation of key CREBBP/p300 substrates, including H3K27, p53, and BCL6, leading to enhanced apoptosis and altered B-cell diTerentiation. YF2 is well tolerated in vivo and extends survival in both cell line- and patient-derived xenograft mouse models. Moreover, YF2 exposure upregulates antigen-presentation markers and reshapes the immune microenvironment, strengthening responses to immune checkpoint blockade. Taken together, these findings support pharmacologic activation of CREBBP/p300 with YF2 as a compelling therapeutic strategy for B-cell lymphoma. Significance YF2 stimulates CREBBP/p300 activity to normalize B-cell diTerentiation and enhance immune recognition, oTering a potential approach to limit lymphoma progression and strengthen immunotherapy responses.

Background: The Phase 1/2 ECOG-ACRIN sponsored intergroup trial E4412 (NCT01896999) investigated brentuximab vedotin (BV) combined with the checkpoint inhibitors nivolumab (N) and ipilimumab (I) in patients with relapsed or refractory classic Hodgkin lymphoma (R/R HL). Here we present the safety and efficacy results for the cohort of pediatric patients aged 12-17 years. Methods: Patients were randomly assigned to treatment with the doublet of BV/N or triplet of BV/N/I, with the following dosing: BV 1.8mg/kg every 21 days for up to 16 cycles; Nivolumab 3mg/mg every 21 days for up to 34 cycles; Ipilimumab 1mg/kg every 9 weeks for up to 9 doses. Response evaluation by PET/CT was performed after 4 cycles. Transplant-eligible patients with CR could discontinue protocol therapy to receive a consolidative autologous stem cell transplant (ASCT). Results: Sixteen pediatric patients with a median age of 16 (range 12-17) were randomized. 75% of patients had received only 1 prior line of treatment with none having previously received BV and only 1 patient with prior ASCT. All patients were treated (8 in each arm) and included in the pediatric safety analysis cohort receiving at least one cycle of therapy. There were four reported grade (gr) 3 or greater toxicities: lymphopenia (gr 3) and neutropenia (gr 3) on the BV/N arm; and neutropenia (gr 4) and rash (gr 3) on the BV/N/I arm. Rash of any grade was more common in patients treated with BV/N/I (n=6) compared to BV/N (n=1). Peripheral sensory neuropathy was reported in 2 patients (BV/N, gr 2, n=2) There were no grade 5 toxicities. Fourteen patients (7 in each arm) were evaluable for response. The CR rate on both the BV/N and BV/N/I arms was 100%. The median survival follow up was 23.7 months (15.7 - 31.7). The 24-month PFS was 57% for BV/N and 100% for BV/N/I. Six patients (2 BV/N; 4 BV/N/I) discontinued protocol therapy to receive a consolidative ASCT. The 24-month PFS for patients consolidated with an ASCT was 100%, with all events occurring in patients randomized to BV/N, but not receiving an ASCT. Conclusion: Pediatric patients receiving both BV/N and BV/N/I had 100% CR rate with limited toxicity. Although this is a small cohort, there have been no progression events observed in patients treated with BV/N/I, including 3 patients treated without a consolidative ASCT.

Background: Relapsed/refractory (R/R) Classic Hodgkin lymphoma (cHL) remains a significant clinical challenge. We hypothesized that using immune checkpoint blockade to activate the immune cells in the tumor microenvironment, and concurrently targeting tumor cells with the CD30 targeting antibody-drug conjugate brentuximab vedotin (BV) could overcome tumor resistance. E4412 is an intergroup Phase 1/2 ECOG-ACRIN sponsored study of the combinations of BV, nivolumab (N), and ipilimumab (I) in patients with R/R cHL. Here we present the efficacy and safety data on the full adult cohort of patients treated in Phase 2 randomized between BV/N and BV/N/I. Methods: Patients with confirmed R/R cHL were randomized between the doublet of BV/N with BV 1.8mg/kg and N 3mg/kg and BV/N/I with I 1mg/kg. BV and N were administered every 3 weeks, and I every 12 weeks for up to 1 year for BV and up to 2 years for N and I. Results: One hundred twenty-six patients were enrolled and treated; 8 patients (4 from each arm) were excluded from efficacy analysis based on ineligibility. Patients were not heavily pretreated, 65% had one prior line of therapy and an additional 27% had two prior lines, and 8% had more than 2 prior lines. The median age was 34; 51% of patients were male. Sixteen patients had prior BV: 10 (BV/N arm) and 6 (BV/N/I). Response: One hundred eighteen patients are evaluable for response: 61 treated with BV/N and 57 with BV/N/I. With BV/N 37 of 61 (60.7%) of patients had a complete response (CR) compared to 38 of 57 (66.7%) with BV/N/I for a difference of 6.7% (p-value 0.31). Additionally, 17 (28%) with BV/N and 12 (21%) of patients treated with BN/N/I had a partial response (PR) for an overall response rate (ORR) of 88% in both arms. In a planned analysis of patients with prior treatment with BV the CR rate was 25% in BV/N arm (2 of 8) and 60% in BV/N/I arm (3 of 5). The median follow-up for progression free survival (PFS), duration of response (DOR), and overall survival (OS) is 24.8 months and 33.7 months. The median PFS, duration of response and OS have not been reached for either arm with 24 months of follow-up ( Figure 1). In B/N 30 of 61 patients came off study to receive alternative treatments (primarily autologous stem cell transplant (SCT)) and in BV/N/I 23 of 57 patients did. Safety: Table 1 shows treatment-related Grade 3+ toxicity occurring in > 1 patient and adverse events (AE) of special interest. All 126 patients (118 eligible and 8 ineligible) are evaluable for safety. The rate of Grade 3+ treatment related toxicity is 43% (28/65) and 52% (32/61) for BV/N and BV/N/I, respectively. However, when rash is excluded the rate of treatment related toxicities is similar between the two arms 38.5% vs 39.3%. There was no grade 4 rash, and the rash was treatable in all cases with topical or oral steroids. There were no Grade 5 toxicities in either arm. Conclusion: In this randomized Phase 2 study comparing BV/N vs. BV/ N/I the difference in CR rate of 6.7% between the doublet and the triplet was not statistically significant. Additionally, the triplet had more grade 3 rash than the doublet, there was otherwise no significant difference in grade 3 or greater toxicity between the two arms. With a median follow-up of 24 months the PFS and DOR have not been reached for either arm, suggesting excellent disease control from both regimens. Differences in response for BV pre-treated patients between the two arms is intriguing especially as more patients are treated with BV in the frontline, but the sample size is too small to draw firm conclusions. Correlative studies are underway to elucidate a response vs. resistance signature, and biological understanding of differential benefit.

Abstract Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma; data indicate that blastoid and pleomorphic variants have a poor prognosis. We report characteristics and outcomes of patients with blastoid/pleomorphic variants of MCL. We retrospectively studied adults with newly diagnosed MCL treated from 2000 to 2015. Primary objectives were to describe progression-free survival (PFS) and overall survival (OS). Secondary objectives included characterization of patient characteristics and treatments. Of the 1029 patients with MCL studied, a total of 207 neoplasms were blastoid or pleomorphic variants. Median follow-up period was 82 months (range, 0.1-174 months); median PFS was 38 months (95% confidence interval [CI], 28-66) and OS was 68 months (95% CI, 45-96). Factors associated with PFS were receipt of consolidative autologous hematopoietic transplantation (auto-HCT; hazard ratio [HR], 0.52; 95% CI, 0.31-0.80; P < .05), MCL International Prognostic Index (MIPI) intermediate (HR, 2.3; 95% CI, 1.2-4.3; P < .02) and high (HR, 3.8; 95% CI, 2.0-7.4; P < .01) scores, and complete response to induction (HR, 0.29 (95% CI, 0.17-0.51). Receipt of auto-HCT was not associated with OS (HR, 0.69; 95% CI, 0.41-1.16; P = .16) but was associated with MIPI intermediate (HR, 5.7; 95% CI, 2.5-13.2; P < .01) and high (HR, 10.8; 95% CI, 4.7-24.9; P < .01) scores. We report outcomes in a large cohort of patients with blastoid/pleomorphic variant MCL. For eligible patients, receipt of auto-HCT after induction was associated with improved PFS but not OS. Higher MIPI score and auto-HCT ineligibility were associated with worse survival.