Citations

Abstract Recurrent chromosomal rearrangements are a hallmark of hematologic malignancies and play critical roles in pathogenesis. The TP53 analog TP63 is rearranged in 5-10% of diverse subtypes of both aggressive T- and B-cell lymphomas. Patients with TP63-rearranged lymphomas have dismal outcomes, with 5-year overall survival rates between 0-17%, depending on cohorts. The function and mechanisms of TP63 rearrangements and TP63 fusion proteins in tumorigenesis are poorly understood. As a result, attempts to treat these patients to date have been largely empiric. Thus, there is an urgent need to understand how TP63 fusions contribute to tumorigenesis and to translate the findings into novel therapeutic options for these patients. Here, we demonstrated that TP63 fusions are essential for the propagation of T-cell lymphomas (TCLs). Knockdown of TP63 fusions with specific shRNAs in TCL cell lines harboring TP63 fusions suppressed both cell growth in vitro and tumor growth in vivo. Retroviral expression of TBL1XR1-TP63, the most common TP63 fusion, conferred cytokine independence in Ba/F3 cells, consistent with its role as an oncogene. To investigate the role of TP63 fusions in T- and B-cell lymphomagenesis, we engineered a CAG-Loxp-Stop-Loxp-TBL1XR1-TP63 conditional knock-in mouse model and crossed with hCD2-Cre mice. This results in expression beginning during early lymphoid development. As observed in patients, transgenic mice developed multiple subtypes of both T- and B-cell lymphoma. To define the effects and mechanisms of TP63 fusions within T cells, we performed CRISPR scanning, transcriptomic, epigenomic, and proteomic analyses. Our data showed that domains within both the N-terminal TBL1XR1 and C-terminal TP63 portions contribute to the function of this fusion. We found that the N-terminal component of TP63 fusions interacts with components of the NCOR/SMRT complex. At the same time, the C-terminal portion of TP63 (which recapitulates the deltaN-p63 isoform expressed in some carcinomas) interacts with the enhancer modifier KMT2D and its complex members. TBL1XR1-TP63 binds to a novel distal enhancer to drive MYC expression, and thus upregulates the expression of the histone H3K27 methylase EZH2. Finally, we assessed whether EZH2 is a vulnerability of TP63-rearranged lymphomas. We found that knockdown of EZH2 in TP63-rearranged lines significantly impaired cell growth, as did treatment with the EZH2 and 1 dual inhibitor valemetostat. Valemetostat, which is now being tested in patients with lymphoma, counteracted the oncogenic effects of TP63 fusions in multiple preclinical models in vivo. Together, our results identify the TP63 fusion as a highly unique oncogenic driver in lymphomagenesis capable of recruiting multiple epigenetic modifier complexes and inducing a targetable dependence on EZH2. Citation Format: Gongwei Wu, Noriaki Yoshida, Jihe Liu, Xiaoyang Zhang, Yuan Xiong, Tayla Heavican-Foral, Huiyun Liu, Geoffrey Nelson, Lu Yang, Renee Chen, Katherine Donovan, Marcus Jones, Mikhail Roshal, Yanming Zhang, Ran Xu, Ajit Nirmal, Salvia Jain, Catharine Leahy, Kristen Jones, Kristen Stevenson, Natasha Galasso, Nivetha Ganesan, Tiffany Chang, Wen-Chao Wu, Abner Louissaint, Lydie Debaize, Hojong Yoon, Paola Dal Cin, Wing Chan Chan, Shannan Ho Sui Ho Sui, Samuel Ng, Andrew Feldman, Steven M. Horwitz, Mathew Meyerson, Karen Adelman, Eric Fischer, Chun-Wei Chen, David Weinstock, Myles Brown. TP63 fusions drive enhancer rewiring, lymphomagenesis, and dependence on EZH2. [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 5755.

AbstractBackground and ObjectivesConvalescent COVID‐19 plasma (CCP) was developed and used worldwide as a treatment option by supplying passive immunity. Adult studies suggest administering high‐titer CCP early in the disease course of patients who are expected to be antibody‐negative; however, pediatric experience is limited. We created a multi‐institutional registry to characterize pediatric patients (<18 years) who received CCP and to assess the safety of this intervention.MethodsA REDCap survey was distributed. The registry collected de‐identified data including demographic information (age, gender, and underlying conditions), COVID‐19 disease features and concurrent treatments, CCP transfusion and safety events, and therapy response.ResultsNinety‐five children received CCP: 90 inpatients and 5 outpatients, with a median age of 10.2 years (range 0–17.9). They were predominantly Latino/Hispanic and White. The most frequent underlying medical conditions were chronic respiratory disease, immunosuppression, obesity, and genetic syndromes. CCP was primarily given as a treatment (95%) rather than prophylaxis (5%). Median total plasma dose administered and transfusion rates were 5.0 ml/kg and 2.6 ml/kg/h, respectively. The transfusions were well‐tolerated, with 3 in 115 transfusions reporting mild reactions. No serious adverse events were reported. Severity scores decreased significantly 7 days after CCP transfusion or at discharge. Eighty‐five patients (94.4%) survived to hospital discharge. All five outpatients survived to 60 days.ConclusionsCCP was found to be safe and well‐tolerated in children. CCP was frequently given concurrently with other COVID‐19‐directed treatments with improvement in clinical severity scores ≥7 days after CCP, but efficacy could not be evaluated in this study.

Abstract Objective Flares of autoimmune rheumatic diseases (AIRDs) following COVID-19 vaccination are a particular concern in vaccine-hesitant individuals. Therefore, we investigated the incidence, predictors and patterns of flares following vaccination in individuals living with AIRDs, using global COVID-19 Vaccination in Autoimmune Diseases (COVAD) surveys. Methods The COVAD surveys were used to extract data on flare demographics, comorbidities, COVID-19 history, and vaccination details for patients with AIRDs. Flares following vaccination were identified as patient-reported (a), increased immunosuppression (b), clinical exacerbations (c) and worsening of PROMIS scores (d). We studied flare characteristics and used regression models to differentiate flares among various AIRDs. Results Of 15 165 total responses, the incidence of flares in 3453 patients with AIRDs was 11.3%, 14.8%, 9.5% and 26.7% by definitions a–d, respectively. There was moderate agreement between patient-reported and immunosuppression-defined flares (K = 0.403, P = 0.022). Arthritis (61.6%) and fatigue (58.8%) were the most commonly reported symptoms. Self-reported flares were associated with higher comorbidities (P = 0.013), mental health disorders (MHDs) (P &lt; 0.001) and autoimmune disease multimorbidity (AIDm) (P &lt; 0.001). In regression analysis, the presence of AIDm [odds ratio (OR) = 1.4; 95% CI: 1.1, 1.7; P = 0.003), or a MHD (OR = 1.7; 95% CI: 1.1, 2.6; P = 0.007), or being a Moderna vaccine recipient (OR = 1.5; 95% CI: 1.09, 2.2; P = 0.014) were predictors of flares. Use of MMF (OR = 0.5; 95% CI: 0.3, 0.8; P = 0.009) and glucocorticoids (OR = 0.6; 95% CI: 0.5, 0.8; P = 0.003) were protective. A higher frequency of patients with AIRDs reported overall active disease post-vaccination compared with before vaccination (OR = 1.3; 95% CI: 1.1, 1.5; P &lt; 0.001). Conclusion Flares occur in nearly 1 in 10 individuals with AIRDs after COVID vaccination; people with comorbidities (especially AIDm), MHDs and those receiving the Moderna vaccine are particularly vulnerable. Future avenues include exploring flare profiles and optimizing vaccine strategies for this group.

Background: Risk for venous thromboembolism has a strong genetic component. Whole genome sequencing from the TOPMed program (Trans-Omics for Precision Medicine) allowed us to look for new associations, particularly rare variants missed by standard genome-wide association studies. Methods: The 3793 cases and 7834 controls (11.6% of cases were individuals of African, Hispanic/Latino, or Asian ancestry) were analyzed using a single variant approach and an aggregate gene-based approach using our primary filter (included only loss-of-function and missense variants predicted to be deleterious) and our secondary filter (included all missense variants). Results: Single variant analyses identified associations at 5 known loci. Aggregate gene-based analyses identified only PROC (odds ratio, 6.2 for carriers of rare variants; P =7.4×10 −14 ) when using our primary filter. Employing our secondary variant filter led to a smaller effect size at PROC (odds ratio, 3.8; P =1.6×10 −14 ), while excluding variants found only in rare isoforms led to a larger one (odds ratio, 7.5). Different filtering strategies improved the signal for 2 other known genes: PROS1 became significant (minimum P =1.8×10 −6 with the secondary filter), while SERPINC1 did not (minimum P =4.4×10 −5 with minor allele frequency <0.0005). Results were largely the same when restricting the analyses to include only unprovoked cases; however, one novel gene, MS4A1 , became significant ( P =4.4×10 −7 using all missense variants with minor allele frequency <0.0005). Conclusions: Here, we have demonstrated the importance of using multiple variant filtering strategies, as we detected additional genes when filtering variants based on their predicted deleteriousness, frequency, and presence on the most expressed isoforms. Our primary analyses did not identify new candidate loci; thus larger follow-up studies are needed to replicate the novel MS4A1 locus and to identify additional rare variation associated with venous thromboembolism.

AbstractHaploidentical donors offer a potentially readily available donor, especially for non-White patients, for blood or marrow transplantation (BMT). In this collaboration across North America, we retrospectively analyzed outcomes of first BMT using haploidentical donor and posttransplantation cyclophosphamide (PTCy) in MDS/MPN-overlap neoplasms (MDS/MPN), an otherwise incurable hematological neoplasm. We included 120 patients, 38% of non-White/Caucasian ethnicity, across 15 centers with median age at BMT 62.5 years. The median follow-up is 2.4 years. Graft failure was reported in 6% patients. At 3-years, nonrelapse mortality (NRM) was 25%, relapse 27%, grade 3-4 acute graft versus host disease (GVHD) 12%, chronic GVHD requiring systemic immunosuppression 14%, progression-free survival (PFS) 48% and overall survival (OS) 56%. On multivariable analysis, statistically significant associations included older age at BMT (per decade increment) with NRM (sdHR 3.28, 95%CI 1.30-8.25), PFS (HR 1.98, 95% 1.13-3.45) and OS (HR 2.01, 95% CI 1.11-3.63), presence of mutation in EZH2/RUNX1/SETBP1 with relapse (sdHR 2.61, 95%CI 1.06-6.44), and splenomegaly at BMT/prior splenectomy with OS (HR 2.20, 95%CI 1.04-4.65). Haploidentical donors are a viable option for BMT in MDS/MPN, especially for those disproportionately represented in the unrelated donor registry. Disease-related factors including splenomegaly and high-risk mutations dominate outcomes following BMT.

A 35-year-old male greenhouse worker presented with myalgia, fatigue, and fever. Initially, he was thought to have an unspecified viral infection and was treated with conservative therapy. However, the patient’s symptoms persisted, and he reported additional symptoms of mild abdominal pain and headaches. Laboratory evaluation was significant for elevated liver enzymes. Due to concern for acute hepatitis and persistent fever the patient was hospitalized. During his hospital course, no infectious etiology was found to explain his symptoms. After discharge from the hospital, additional testing showed positive serology for Q fever IgG phase II antibody (1:8192) and phase II antibody IgM (> 1:2048). He was treated with doxycycline and had a good clinical response. Upon follow-up, he had worsening Phase I IgG serologies. Transesophageal echo demonstrated vegetations consistent with endocarditis.

Importance Reduced heart rate during exercise is common and associated with impaired aerobic capacity in heart failure with preserved ejection fraction (HFpEF), but it remains unknown if restoring exertional heart rate through atrial pacing would be beneficial. Objective To determine if implanting and programming a pacemaker for rate-adaptive atrial pacing would improve exercise performance in patients with HFpEF and chronotropic incompetence. Design, Setting, and Participants Single-center, double-blind, randomized, crossover trial testing the effects of rate-adaptive atrial pacing in patients with symptomatic HFpEF and chronotropic incompetence at a tertiary referral center (Mayo Clinic) in Rochester, Minnesota. Patients were recruited between 2014 and 2022 with 16-week follow-up (last date of follow-up, May 9, 2022). Cardiac output during exercise was measured by the acetylene rebreathe technique. Interventions A total of 32 patients were recruited; of these, 29 underwent pacemaker implantation and were randomized to atrial rate responsive pacing or no pacing first for 4 weeks, followed by a 4-week washout period and then crossover for an additional 4 weeks. Main Outcomes and Measures The primary end point was oxygen consumption (V̇ o 2 ) at anaerobic threshold (V̇ o 2,AT ); secondary end points were peak V̇ o 2 , ventilatory efficiency (V̇ e /V̇ co 2 slope), patient-reported health status by the Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS), and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. Results Of the 29 patients randomized, the mean age was 66 years (SD, 9.7) and 13 (45%) were women. In the absence of pacing, peak V̇ o 2 and V̇ o 2 at anaerobic threshold (V̇ o 2,AT ) were both correlated with peak exercise heart rate ( r = 0.46-0.51, P &amp;lt; .02 for both). Pacing increased heart rate during low-level and peak exercise (16/min [95% CI, 10 to 23], P &amp;lt; .001; 14/min [95% CI, 7 to 21], P &amp;lt; .001), but there was no significant change in V̇ o 2,AT (pacing off, 10.4 [SD, 2.9] mL/kg/min; pacing on, 10.7 [SD, 2.6] mL/kg/min; absolute difference, 0.3 [95% CI, −0.5 to 1.0] mL/kg/min; P = .46), peak V̇ o 2 , minute ventilation (V̇ e) /carbon dioxide production (V̇ co 2 ) slope, KCCQ-OSS, or NT-proBNP level. Despite the increase in heart rate, atrial pacing had no significant effect on cardiac output with exercise, owing to a decrease in stroke volume (−24 mL [95% CI, −43 to −5 mL]; P = .02). Adverse events judged to be related to the pacemaker device were observed in 6 of 29 participants (21%). Conclusions and Relevance In patients with HFpEF and chronotropic incompetence, implantation of a pacemaker to enhance exercise heart rate did not result in an improvement in exercise capacity and was associated with increased adverse events. Trial Registration ClinicalTrials.gov Identifier: NCT02145351

PURPOSE Brexucabtagene autoleucel (brexu-cel) is an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory mantle cell lymphoma (MCL). This therapy was approved on the basis of the single-arm phase II ZUMA-2 trial, which showed best overall and complete response rates of 91% and 68%, respectively. We report clinical outcomes with brexu-cel in the standard-of-care setting for the approved indication. PATIENTS AND METHODS Patients who underwent leukapheresis between August 1, 2020 and December 31, 2021, at 16 US institutions, with an intent to manufacture commercial brexu-cel for relapsed/refractory MCL, were included. Patient data were collected for analyses of responses, outcomes, and toxicities as per standard guidelines. RESULTS Of 189 patients who underwent leukapheresis, 168 (89%) received brexu-cel infusion. Of leukapheresed patients, 79% would not have met ZUMA-2 eligibility criteria. Best overall and complete response rates were 90% and 82%, respectively. At a median follow-up of 14.3 months after infusion, the estimates for 6- and 12-month progression-free survival (PFS) were 69% (95% CI, 61 to 75) and 59% (95% CI, 51 to 66), respectively. The nonrelapse mortality was 9.1% at 1 year, primarily because of infections. Grade 3 or higher cytokine release syndrome and neurotoxicity occurred in 8% and 32%, respectively. In univariable analysis, high-risk simplified MCL international prognostic index, high Ki-67, TP53 aberration, complex karyotype, and blastoid/pleomorphic variant were associated with shorter PFS after brexu-cel infusion. Patients with recent bendamustine exposure (within 24 months before leukapheresis) had shorter PFS and overall survival after leukapheresis in intention-to-treat univariable analysis. CONCLUSION In the standard-of-care setting, the efficacy and toxicity of brexu-cel were consistent with those reported in the ZUMA-2 trial. Tumor-intrinsic features of MCL, and possibly recent bendamustine exposure, may be associated with inferior efficacy outcomes.