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OBJECTIVE To evaluate a regimen of inhaled Technosphere insulin (TI) plus insulin degludec in adults with type 1 diabetes, who prestudy were predominately using either an automated insulin delivery (AID) system or multiple daily insulin injections (MDI) with continuous glucose monitoring. RESEARCH DESIGN AND METHODS At 19 sites, adults with type 1 diabetes were randomly assigned to TI plus insulin degludec (N = 62) or usual care (UC) with continuation of prestudy insulin delivery method (N = 61) for 17 weeks. RESULTS Prestudy, AID was used by 48% and MDI by 45%. Mean ± SD HbA1c was 7.57% ± 0.97% at baseline and 7.62% ± 1.06% at 17 weeks in the TI group and 7.59% ± 0.80% and 7.54% ± 0.77%, respectively, in the UC group (adjusted difference 0.11%, 95% CI −0.10 to 0.33, P value for noninferiority = 0.01). HbA1c improved from baseline to 17 weeks by >0.5% (5.5 mmol/mol) in 12 (21%) in the TI group and in 3 (5%) in the UC group and worsened by >0.5% (5.5 mmol/mol) in 15 (26%) in the TI group and in 2 (3%) in the UC group. The most common TI side effect was a brief cough; eight participants discontinued TI due to side effects. CONCLUSIONS In adults with type 1 diabetes, HbA1c after 17 weeks with a regimen of TI and degludec was noninferior to UC, which consisted predominately of either AID or MDI. TI should be considered an option for people with type 1 diabetes, particularly those who are motivated to further reduce postprandial hyperglycemia.

Background: TP53-mutated (TP53mut) myeloid neoplasms (MN) have particularly poor survival. Discrepancies in defining TP53mut MN have impact on diagnostic work up, therapeutic decisions, and clinical trial enrolment. Methods: MN cases harboring TP53mut (variant allele frequency, VAF ≥2%) were classified based on bone marrow (BM) and peripheral blood (PB) blast % using the 4th revision of the WHO classification (WHO-4R). Biallelic loss was defined as (i) ≥2 mutations each with VAF ≥2%; (ii) single TP53mut VAF ≥2% plus 17p loss detected on karyotype, FISH, or SNP; or (iii) single TP53mut VAF ≥50%, whereas monoallelic loss was defined as single TP53mut VAF <50% without 17p loss. Primary endpoint was overall survival (OS) from diagnosis. Conditional Inference Trees (CIT) analysis was used to determine the true effect of a predictor. Results: We identified 580 cases including WHO-4R defined acute myeloid leukemia (AML, BM/PB blasts ≥20%, n=219, 37.8%), myelodysplastic syndrome (MDS) with excess blasts-2 (EB-2, BM 10-19% or PB 5%-19%, n=92, 15.9%), MDS with excess blasts-1 (EB-1, BM 5-9% or PB 2-4%, n=75, 12.9%), and the remaining were MDS with low blasts (-LB, BM <5% and PB ≤1%, n=194, 33.4%). Of the 578 cases evaluable for allelic status, 437 (75.6%) and 141 (24.4%) had biallelic and monoallelic TP53 loss, respectively. Higher frequency of biallelic loss was observed with increasing blasts. 63.2%, 73.3%, 78% and 86.3% of cases with MDS-LB, MDS-EB1, MDS-EB2, and AML had bi-allelic TP53 loss (P<0.0001). In a multivariable analysis, WHO-4R categories, VAF ≥10%, and biallelic loss were independent predictors of poor survival. CIT analysis further stratified the cohort into 4 groups with distinct survival: (1) MDS-LB (n=194, 33.4%); (2) MDS-EB1/EB2 and AML with VAF <10% (n=38, 6.6%); (3) MDS-EB1/EB2 with VAF ≥10% (n=149, 25.7%); and (4) AML with VAF ≥10% (n=199, 34.3%). MDS-LB cases could be further stratified based on allelic status and complex karyotype (CK): OS was poor for cases with biallelic TP53 loss and monoallelic TP53mut with CK compared to monoallelic TP53mut without CK, who had the most favorable survival (12.7 vs. 13 vs. 34.8 months, P<0.0001).MDS-EB1/EB2/AML with VAF<10% could also be stratified by CK: MDS-EB1/EB2/AML with VAF<10% cases without CK had the favorable survival compared to their counterparts with CK and MDS-EB1/EB2 with VAF ≥10% cases (26.2 vs. 5.6 vs. 6.3 months, P=0.003).MDS-EB1/EB2 with VAF ≥10% was a homogenous subgroup: Biological characteristics including the proportion of cases with biallelic TP53 loss, CK (P>0.9), monosomal karyotype (MK, P>0.9), del 5q (P=0.6), del 7q (P=0.4), and del 17p (P=0.2) were comparable between MDS-EB1 and -EB2 with VAF ≥10%. Importantly, median OS of MDS-EB1 and EB2 with VAF ≥10% was comparable (9.6 vs. 7.2 months, P=0.12). OS in this group was comparable regardless of the blast %, allelic status, or presence of CK.AML with VAF ≥10% had extremely poor survival: Median OS was 3.9 months. Survival of AML was equally poor irrespective of the mono- or biallelic (3.6 vs. 3.9, P=0.89) and non-CK vs. CK (1.8 vs. 3.9 months, P=0.09). Combined, our model would acknowledge poor survival of 514 (89.1%) cases. In contrast, retrospective application of the 5th edition of the WHO classification (WHO-5) and International Consensus Classification (ICC) would classify only 211 (36.4%) and 468 (80.7%) cases as biallelic/multi-hit TP53mut MN, respectively. Finally, the Harrell's c-index of the proposed model, WHO-5, and ICC was 0.66, 0.571, and 0.617, respectively. Conclusion: We provide evidence for subsequent refinements in classifying MN harboring TP53mut. Our salient findings include: (i) acknowledgement of CK as ‘biallelic equivalent’ in MDS-LB; as well as EB1/EB2/AML with VAF 2 to <10% cases; and (ii) demonstration of poor survival of MDS-EB1 and -EB2 with VAF ≥10% regardless of the allelic status. In conclusion, our proposed model acknowledged poor survival of a higher proportion of cases as TP53mut MN compared to the current models with a higher c- index.

Introduction: Mantle cell lymphoma (MCL) is an uncommon B-cell non-Hodgkin lymphoma (NHL) Prognosis is highly variable due to underlying biological and molecular heterogeneity. The first-line (1L) treatment paradigm for MCL continues to evolve with increasing use of bruton tyrosine kinase inhibitors (BTKi) and decreasing use of autologous stem cell transplant (ASCT). TP53 alterations are associated with inferior outcomes in MCL. The aim of this retrospective study is to determine treatment strategies and clinical outcomes in MCL patients based on TP53 gene mutation status. Methods: Retrospective data were collected from 19 institutions in the United States from 1/1993 to 1/2024. We examined treatment patterns and outcomes among MCL patients >18 years of age with known TP53 mutation status by sequencing. Patients who did not receive treatment were excluded. The analysis was stratified based on presence of TP53 mutations. Systemic therapies were categorized as chemo-immunotherapy (CIT), non-chemotherapy (including monoclonal antibodies, lenalidomide, venetoclax, and novel agents on clinical trial), and regimens containing BTKi. The primary outcome was overall survival (OS) and secondary outcomes were progression free survival (PFS) and time to next treatment (TTNT). OS and PFS were estimated with the Kaplan-Meier method and log-rank tests were used to compare groups. Results: 645 patients were included in the study, with 468 men (72.6%) and median age was 64 years (range 30-89). 230/645 patients (35.7%) had a TP53 mutation, of which 182 (79%) were identified prior to 1L. While the male/female distribution was the same between the mutated and unmutated groups, median age at diagnosis and MIPI risk score was higher in the TP53 mutated group (age 65.9 vs 63.1 yrs, p= 0.015; MIPI 6.4 vs 6.1, p<0.001). TP53 unmutated patients had a median of 1 line of therapy vs. 2 for the mutated group (p<0.001, range 1-8). Blastoid histology and higher ki67 were also associated with the TP53 mutated group (p=0.045, 0.01 respectively) The median OS was 14.2 years for TP53 unmutated and 8.3 years for TP53 mutated patients (p<0.0001). PFS in 1L was 0.95 years in TP53 mutated compared to 2.02 years in TP53 unmutated group (p<0.0001). Selection of 1L therapeutic strategy was not associated with presence of TP53 mutation (Χ2 p= 0.21) although more patients in the TP53 unmutated group underwent ASCT (119/415 vs 38/230; Χ2 p=0.0006) TP53 mutation was associated with inferior survival compared to TP53 unmutated patients for CIT in 1L but the difference did not reach statistical significance when non-chemotherapy regimens and regimens containing BTKi were used. For CIT in 1L, 5 year OS was 78% [71-84%] for unmutated compared to 58% [48-67%] for the mutated group (p=0.0001 ). For non-chemotherapy regimens, 5 year OS for unmutated patients was 73% [52- 86%] compared to 52% [25-73%] for the mutated group (p=0.09). For regimens containing BTKi, 5 year OS for unmutated was 93% [81-97%] compared to 57% [28-78%] for mutated (p=0.07). Within the TP53 mutated group, there were no differences in any clinical outcomes between those receiving CIT, non-chemotherapy, or BTKi in 1L. While median OS appeared numerically longer in the BTKi group (14.4 yrs vs 8.8 yrs for CIT and 6.8 yrs for non-chemotherapy), the difference did not reach statistical significance (p=0.58). In contrast,TP53 unmutated patients who received CIT in 1L had better TTNT (p=0.0039) compared to those in non-chemotherapy and BTKi groups. There was no improvement in PFS (p=0.79) or OS (p=0.47). Conclusions To our knowledge this is the largest retrospective real world dataset of MCL treatment outcomes stratified by TP53 mutation. As in prior studies, TP53 mutation portends a worse prognosis in MCL compared to TP53 unmutated patients, but outcomes are better than historically reported. CIT in 1L was not associated with improved OS in either group. Irrespective of TP53 mutation status, incorporation of BTKi in first line was not associated with improved clinical outcomes. The gap in OS between TP53 mutated and unmutated MCL may be narrowing as treatment paradigms shift away from intensive induction chemotherapy and ASCT, and due to an increasing number of effective therapies for relapsed patients. Clinical trials of novel agents are needed to further improve the OS of TP53 mutated MCL patients.

Background : Maintaining oxygen delivery during conditions of hypoxia is important, particularly for patients with hemoglobinopathies.Evidence in comparative physiology indicates that high hemoglobin-oxygen (Hb-O2) affinity serves as a beneficial hematological adaptation to chronic hypoxia exposure. The improved hypoxia tolerance is likely due to an increase in arterial oxygen saturation with high Hb-O2 affinity. However, the relationship between high Hb-O2 affinity and hypoxia tolerance in humans is not well understood. Etavopivat is a potent, selective, once-daily, oral activator of the red blood cell (RBC) pyruvate kinase isozyme (PKR), with a half-life of ~13 hours, under investigation for the treatment of sickle cell disease (SCD) and other hematological conditions. Etavopivat has a multimodal mechanism of action in RBCs by decreasing 2,3-diphosphoglycerate (2,3-DPG) levels to increase Hb-O2 affinity and increasing adenosine triphosphate (ATP) levels to improve RBC health. In Phase 1 trials etavopivat increased Hb-O2 affinity in healthy volunteers (HVs; Forsyth et al. Clin Pharmacol Drug Dev 2022) and patients with SCD (Saraf et al. Blood Adv 2024) in room air. Aim: To investigate arterial oxygenation changes with etavopivat under conditions of moderate and severe hypoxia in HVs. Methods: HVs visited the laboratory for assessments at baseline and following 7 days of etavopivat exposure (400 mg once daily). Participants completed rhythmic handgrip exercises (rest, 10% and 20% maximum voluntary contraction [MVC]) during graded hypoxic exposure, breathing room air (21% O2), moderate hypoxic gas (15% O2), and severe hypoxic gas (10% O2), resulting in acute duration (~12 minutes) of exposure to each level of hypoxia. Hb-O2 affinity was assessed by partial pressure of oxygen at 50% Hb saturation (P50), measured using dual-wavelength spectrophotometry at a standardized pH (~7.4) and temperature (37 ºC). Arterial catheterization was used to collect samples for fractional oxygen saturation (FO2Hb) and Hb and to measure arterial blood pressure. Blood gases were analyzed after 5 minutes of resting exposure to each inspirate, then ~2.5 minutes after commencing each of the 3-minute handgrip exercises (10% followed by 20% MVC). Liquid chromatography-tandem mass spectrometry was used to evaluate 2,3-DPG and ATP levels in whole blood. Data for FO2Hb and heart rate were analyzed using separate repeated measures 2 (treatment) x 3 (intensity) ANOVA for each inspirate and all other hematological data pre vs post etavopivat were analyzed using paired-sample t-tests. Statistical significance was set at P<0.05. Data presented are mean ± standard deviation. Results: Sixteen HVs (five women) aged 32 ±8 years were enrolled. After 7 days of oral once-daily 400 mg etavopivat, P50 decreased from 28.6 ±1.6 at baseline to 24.8 ±1.3 mmHg (P<0.001). Hb concentration remained unchanged from baseline (14.6 ±1.1 g/dL), post etavopivat (14.5 ±1.1 g/dL; P>0.05). FO2Hb at rest decreased from 96.0% ±0.6 under normal oxygen conditions to 74.6% ±6.7 during severe hypoxic exposure; however, this decrease in FO2Hb was mitigated post etavopivat exposure (79.7% ±5.2, P<0.001). A similar mitigation of the FO2Hb decrease was observed during the handgrip exercise (20% MVC, P<0.001). Concentrations of 2,3-DPG decreased and RBC ATP increased following etavopivat exposure during both normoxia and moderate hypoxia (P<0.001). Mean arterial pressure was lower post etavopivat exposure under normoxia, but not during moderate or severe hypoxia. Heart rate showed no change post etavopivat exposure during normoxia and hypoxia (P>0.50). Etavopivat was well tolerated with no unexpected adverse events reported. Conclusions: Etavopivat enhanced FO2Hb during brief hypoxic episodes with an apparent relationship to hypoxia severity for which the greatest improvements were observed at more severe hypoxic exposure. In SCD, high Hb-O2 affinity is beneficial for maintaining Hb ‘R’ state, thereby reducing the risk of polymerization and associated sickling. Increased Hb-O2 affinity, together with maintenance of a high FO2Hb under hypoxic conditions, demonstrates etavopivat's ability to promote oxygen exchange and subsequent delivery. Together with projected improvement of RBC health, also achieved via PKR activation, this indicates a potential clinical benefit with etavopivat for hemoglobinopathies and beyond.

Background: Polatuzumab vedotin (Pola) is an antibody drug conjugate targeting CD79b that incorporates the microtubule disrupting monomethyl auristatin E payload. Pola was approved in 2023 for the upfront treatment of diffuse large B cell lymphoma (DLBCL) in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (polaRCHP) based on the POLARIX trial. However, the activity of pola appears to vary based on DLBCL cell of origin (COO) subtype, with greater efficacy in activated B cell (ABC) DLBCL compared to germinal center B cell (GCB) DLBCL (Russler-Germain Blood 2023). When outcomes in POLARIX are stratified by COO, polaRCHP demonstrated progression free survival (PFS) and overall survival (OS) benefits over RCHOP in patients with ABC but not GCB subtype DLBCL (PFS HR 0.34 ABC vs 1.03 GCB, OS HR 0.27 ABC vs 1.64 GCB; Morschhauser ASH 2023 and FDA data). Most prospective studies of pola used gene expression to assess COO, which is not readily clinically available. This study aims to examine if COO subtype by Hans algorithm (based on CD10, BCL6, and MUM1 expression by immunohistochemistry) is predictive of pola responses and outcomes in patients with large B cell lymphoma (LBCL). Methods: We conducted a retrospective, multicenter observational study of adults with LBCL who received pola (monotherapy or in combination) from 2015-2024 with Hans algorithm COO data and response assessment available. Patients were stratified by receipt of pola in the frontline vs relapsed/refractory (R/R) setting. The primary endpoint was overall response rate (ORR) to pola-based treatment in GCB vs non-GCB subtypes. Secondary endpoints included complete response rate (CRR), PFS, and OS. For time to event endpoints, patients responding to pola who received CAR T or stem cell transplantation prior to progression were censored at time of cellular therapy. Demographics were summarized by descriptive statistics. Comparative and survival analyses used Chi squared/Fischer exact tests and Kaplan Meier analysis. Data cutoff was July 1, 2024. Results: 718 patients were included. Median follow-up was 15 months (interquartile range [IQR] 8-32). Median age at LBCL diagnosis was 66 years (IQR 56-74); 62% were men; 69 (10%) had double hit lymphoma (DHL); 129 (18%) had underlying low grade lymphoma. Pola was used in the frontline setting in 293 (41%) patients, of whom 139 (47%) had GCB vs 154 (53%) non-GCB COO. Of the 426 patients receiving pola for R/R LBCL (including one patient receiving pola retreatment), 224 (53%) had GCB vs 202 (47%) non-GCB COO. Among patients receiving pola-based regimens in the R/R setting (GCB vs non-GCB: pola monotherapy = 7% vs 4%, pola + R = 26% vs 26%, pola + BR = 55% vs 61%, pola + other = 12% vs 9%; p = 0.44), the ORR in GCB vs non-GCB LBCL was 36% vs 61% (p < 0.001), while CRR in GCB vs non-GCB was 17% vs 36% (p < 0.001). COO remained a significant component of logistic multivariate regression models of ORR (p < 0.001) and CRR (p < 0.001) when incorporating IPI at original LBCL diagnosis, histology, DHL status, and refractory status to frontline therapy. Despite this, no significant PFS or OS differences by COO were seen, potentially due to approximately 1/4 patients being censored due to receiving subsequent cellular therapy (e.g. CAR T) prior to progression. In patients receiving frontline pola-based regimens (of which 275 [94%] included an anthracycline), ORR and CRR were similar in GCB vs non-GCB (ORR 89% vs 88% p > 0.5; CRR 76% vs 77% p > 0.5). While PFS and OS were similar between COO groups in the frontline cohort, follow-up and cohort size were limited. Conclusion: Based on this real-world evidence, COO classification by Hans algorithm is a strong predictor of the activity of pola-containing therapy in R/R LBCL, with significantly higher ORR and CRR in patients with non-GCB compared to GCB COO LBCL. This aligns with the cumulative existing evidence. ORR and CRR to pola-containing therapy in the frontline setting did not differ significantly by COO subtype, but longer follow-up of larger cohorts is needed to clarify the predictive role of COO by Hans algorithm in this setting, especially considering the PFS advantage with polaRCHP in POLARIX was not associated with significant differences in ORR or CRR. Overall, clinicians should consider factoring COO subtype into treatment decisions regarding pola-containing regimens, and studies of pola-based therapies should stratify patients and report outcomes by COO subtype.

Background: Two National Cancer Institute-funded pharmacovigilance programs have identified 49 serious hematology-related ADRs since 1998. The programs, called RADAR (Research on Adverse Drug events and Reports) and then SONAR (Southern Network on Adverse Reactions) involve > 50 institutions and > 75 co-investigators worldwide. The work builds on three prior studies evaluating “Davids and Goliaths” in medical oncology and in cardiology (PLOS One, eClinicalMedicine, and Journal of Scientific and Professional Integrity). Here we review the hematology focused safety investigations of RADAR/SONAR. Methods: Data were based on initial safety signals being identified by a RADAR/SONAR co-investigator. Then, case-series were derived. Collaborations with basic scientists allowed for basic science correlative studies. Results were disseminated primarily as Brief Report in the literature and Black Box warnings on the related drug. In some instances, studies identified hematologic toxicities that prevent FDA from approving a submitted drug application. Results: sADRs were frequently identified based on very small case series, including ticlopidine-and clopidogrel associated thrombotic thrombocytopenic purpura (22 and 10 patients, respectively), thalidomide- and lenalidomide-associated venous thromboembolism (9 and 5 patients, respectively), rituximab-associated progressive multi-focal leukoencephalopathy (22 patients), peginesatide-associated fatal anaphylaxis (5 patients), and COVID-19 vaccine associated immune thrombocytopenia (1 patient). Meta-analyses provided data for epoetin- and darbepoetin-associated mortality among cancer patients and lenalidomide- and thalidomide-associated venous thromboembolism. Following the onset of the COVID-19 pandemic, RADAR/SONAR investigated social media and pre-prints (COVID-19 vaccine associated cerebral vein thrombosis and immune thrombocytopenia). Time from FDA approval to sADR discovery was a median of 5 years (range, 0 months (thalidomide-associated venous thromboembolism) to 34 years (ciprofloxacin-associated neuropsychiatric toxicity). Basic science correlative studies identified ADAMTS13 autoantibodies (ticlopidine), leachates that developed in a multi-dose vial (peginesatide), anti-red blood cell antibodies (epoetin-associated pure red cell aplasia), and high-risk genes (fluoroquinolones and rituximab). Overall, RADAR/SONAR studies are estimated to have saved over 1 million lives and also resulted in overall payments to the Department of Justice of $1.5 billion (related to marketing of unsafe drugs). Discussion: RADAR/SONAR has proven to be a very important adjunct to FDA and pharmaceutical manufacturer-led safety investigations for hematology, paralleling the success in medical oncology and in cardiology. Going forward, independent centers of excellence for safety-focused investigations such as the CERSI network and the SENTINEL network (both are NIH funded) should be broadened to include a hematology-focused safety center.

Background: TP53 mutations (TP53mut) are highly prevalent in therapy-related myeloid neoplasms (t-MN) compared to de novo MN (35-40% vs 7-13%) and are associated with a poor outcome. Understanding the risk factors involved in the pathogenesis of TP53mut t-MN is critical to prevent its development. Methods: We characterized t-MN cases by examining primary cancer type vs autoimmune disease diagnosis vs solid organ transplantation, treatment modality, and latency (interval between primary cancer/disease and t-MN diagnosis) to identify patient and disease-related factors associated with TP53mut t-MN. Allelic loss of TP53mut MN was defined according to International Consensus Classification (ICC) criteria (Arber et al., Blood 2022). Results: Of 587 t-MN patients, 33% (n=194) had acute myeloid leukemia (t-AML) and 67% (n=393) had myelodysplastic syndrome (t-MDS, blasts<20%). Primary diagnosis comprised of 243 (41.6%) solid cancers and 300 (51.4%) hematological malignancies, while 7% (n=41) of t-MN cases had autoimmune disease or underwent solid organ transplant. Overall, 94 (16.1%) patients received prior radiotherapy (RT) alone and 75.6% (n=444) received chemotherapy (CT) with/without RT. 109 patients (18.7%) underwent autologous stem cell transplant (ASCT). The median latency from primary diagnosis to t-MN was 83.2 months (IQR 41.3, 153.2), and there was a trend towards shorter latency in t-AML compared to t-MDS (70.5 vs 85.8 months; P=0.07). Of the t-MN patients, 280 (47.7%) harbored TP53mut, which was associated with significantly poorer survival compared to wild-type (TP53wt) t-MN (9.7 vs 21.9 months; P <0.001). In contrast to TP53wt (59.0% vs 41.0%), the majority of TP53mut t-MN presented with t-MDS vs t-AML (75.7% vs 24.3%; P <0.001). According to ICC criteria, multi-hit MDS (n=131; 47.8%) was the most common entity, followed by AML (n=68; 24.8%), MDS/AML (n=34; 12.4%), and single-hit MDS (n=8, 2.9%). Poor prognostic karyotype changes e.g., del 5q, del 7q, complex karyotype and monosomal karyotype, were more prevalent in TP53mut compared to TP53wt t-MN. Co-mutations in other genes were enriched in TP53wt t-MN. As TP53mut t-MN is associated with a dismal outcome, we assessed the factors associated with its development. There were no significant differences in median age at primary cancer/disease diagnosis (59.0 vs 59.9 years; P=0.4) or gender (females 43.3% vs 39.3%; P=0.3) between TP53mut and TP53wt t-MN. However, TP53mut patients were older at t-MN diagnosis (69 vs 67.4 years; P=0.05). Correlations between gene mutations and prior malignancies revealed a significant association between TP53mut and hematological primary cancers (odds ratio [OR] 1.6; P=0.006), especially multiple myeloma (MM, OR 4.9; P<0.001) and lymphoproliferative disease (LPD, OR 2.0; P=0.013). Among solid cancers, head and neck malignancies were significantly associated with increased risk of developing TP53mut t-MN (OR 7.7; P=0.01). Compared to RT alone, ASCT (OR 2.2; P=0.004) and CT (OR 2.0; P=0.008) were associated with an increased risk of TP53mut t-MN. Recent studies indicate that CT/RT confer a selective advantage to preexisting TP53mut hematopoietic stem and progenitor cells, allowing clonal expansion/evolution and progression to t-MN. We hypothesized that TP53mut t-MN with high-risk disease features is a function of TP53mut clonal expansion/evolution rate and would predict latency between primary cancer and t-MN. Indeed, the latency between primary cancer and t-MN diagnosis was longer in TP53mut (87.8 months, IQR 45.5, 154.1) compared to TP53wt (74.7 months, IQR 37.5, 146.9 months) t-MN (P=0.05). Interestingly, 54% and 29% of TP53mut t-MN had a latency of ≥5 and ≥10 years, respectively. There were no correlations between latency and TP53 variant allele frequency (VAF) (r=0.38 and P=0.7) or between TP53mut t-MDS and t-AML (85.2 vs 109.3 months; P=0.9). Together, latency between primary cancer and t-MN was not associated with TP53mut t-MN phenotype, VAF or other poor-risk disease features. Conclusion: Hematological malignancies, especially MM and LPD treated with high-dose CT, were strongly associated with TP53mut t-MN development, highlighting the importance of careful and ongoing screening in this population. Also, the long latency of TP53mut t-MN provides an opportunity to devise effective surveillance strategies and preventative interventions long before TP53mut t-MN development.

Introduction: The combination of chemotherapy and immunotherapy, commonly referred to as chemo-immunotherapy (CIT), has long been a cornerstone in the treatment of lymphoma. Although this approach has resulted in successful treatments for many patients (pts), a significant number continue to experience unfavorable results, underscoring the urgency for improved treatments. There is still a significant gap in knowledge about the immune profile of lymphoma pts, specifically in terms of (1) how their immune phenotype compare to those of healthy individuals and (2) how treatment affects their immune system. This study aimed to compare the immune profiles of lymphoma pts (at baseline) to that of matched healthy controls, and track the changes in the immune system during and after lymphoma treatment. Methods: Pts with newly diagnosed, untreated lymphoma, without prior history of cancer or autoimmunity were enrolled in the Dyna-RISC study. Whole blood samples were collected at baseline (BL), on day 1 of cycle 2 (C2D1), on day 1 of last cycle (CLD1), and 6 months after completion of therapy (6mo). Age- and gender-matched healthy individuals provided blood for baseline comparison. Samples were stained fresh with a pre-mixed lyophilized cocktail containing 30 metal-tagged monoclonal antibodies (Maxpar Direct Immune Profile Assay), fixed and cryopreserved. Samples were barcoded and acquired in batches on the Helios CyTOF (cytometry by time-of-flight) system. Cytometry data was analyzed using OMIQ. Differential abundance analysis was performed using relative frequencies of cell subsets (% of parent) using a false-discovery rate of 0.05 to account for multiple comparisons. Results: Between 11/2020 and 06/2021, 15 lymphoma pts were enrolled. Median age was 62 years (range 43-86), 5 pts (33%) were female. Five pts had follicular lymphoma (FL), 3 had diffuse large B-cell lymphoma (DLBCL),1 had primary mediastinal B-cell lymphoma (PBML), 1 had classic Hodgking lymphoma (cHL), 1 had mantle cell lymphoma (MCL), 1 had plasmablastic lymphoma (PBL), 1 had splenic marginal zone lymphoma (SpMZL), 1 had ALK- anaplastic large cell lymphoma (ALCL), 1 had subcutaneous panniculitis-like T-cell lymphoma (SPTCL). Four pts received bendamustine plus rituximab (BR) and 7 pts received R-CHOP. In total, more than 30 million cellular events were acquired, resulting in over 18 million analyzable live single-cell events after expert manual gating. A total of 27 cell subsets were identified within 9 major immune cell compartments. At baseline, lymphoma pts showed significant reduction (p<0.05) of CD4+ naïve T cells (median 1.37%, range 0.33%-9.01%) compared to controls (median 9.28%, range 3.44-21.3%). Concurrently, lymphoma patients at baseline had significant elevation (p<0.05) of intermediate monocytes (median 2.1%, range 0.64%-5.73%) compared to controls (median 0.8%, range 0.2%-2.73%). Naïve cytotoxic T cells were significantly increased (p<0.05) in lymphoma pts at the 6mo timepoint (median 2.08%, range 0.7%-7.46%) compared to baseline (median 0.23%, range 0.03%-4.79%). A sub-group analysis restricted to patients who received either BR or R-CHOP with 6mo timepoint samples available (n=10), showed a significant reduction (p<0.05) in the frequency of CD4+ central memory T cells in the BR group (median 0.76%, range 0.06%-1.02%) compared to the R-CHOP group (median 3.3%, range 2.19%-5.0%). Additional results describing the details of the immune profile dynamics at intermediate timepoints (C2D1, CLD1) will be presented at the conference. Conclusion: Our results suggest that lymphoma patients have an unfavorable immune profile (high intermediate monocytes combined with low naïve CD4+ T cells) at the time of diagnosis, compared to matched healthy individuals. Their immune profile is reshaped after treatment with increase in naïve cytotoxic T cells 6 months after therapy. Bendamustine-based treatment seems to particularly affect T cell recovery post-therapy, leading to a reduction in CD4+ central memory T cells, compared to patients treated with R-CHOP. These findings highlight the importance of studying baseline and treatment-mediated immune changes in lymphoma pts. This characterization is of special interest in the context of therapies that rely on the fitness of immune cells to mediate an effect, such as chimeric antigen receptor (CAR) T cell therapy and bispecific T cell engagers (BiTEs).

Background: Follicular dendritic cell sarcoma (FDCS) is a rare low- to intermediate-grade sarcoma, typically presenting as a slowly growing, painless mass composed of spindle-shaped cells in a whorled pattern. First described in 1986, FDCS has since been identified in several hundred cases. FDCS originates from mesenchymal dendritic cells and is distinct from other histiocytic neoplasms. Its management aligns more with soft tissue sarcomas. Epidemiologically, FDCS is exceedingly rare, constituting less than 0.4% of soft tissue sarcomas. Methods: With IRB approval, we identified patients with biopsy-proven FDCS treated at Mayo Clinic. Chart review extracted clinical characteristics, laboratory testing, treatment data, and clinical outcomes, compiled into Excel. Data analysis was performed through RStudios. Descriptive statistics of patient characteristics, such as gender and stage of disease, were summarized in tables. We compared overall survival (OS) through Kaplan Meier curves, stratifying patients into cohorts based on topics of interest, such as differences in survival in nodal vs. extranodal disease or differences in survival among different chemotherapy regimens. Results: Forty patients met the inclusion criteria, of biopsy proved FCDS. Median age at diagnosis was 57.7 years (SD 14). Men comprised 45% of patients. Locations of malignancy were abdomen and pelvis (32.5%), thoracic and pulmonary regions (32.5%), lymph nodes and neck (20.0%), musculoskeletal (2.5%), and other locations (12.5%). Primary therapies included surgical resection (42.5%), systemic chemotherapy (32.5%), no treatment (10.0%), radiation (2.5%), with data missing for 12.5% of cases. Concurrent or preceding Castleman's Disease was seen in 7.5% (3/40) of patients; one case preceded FCDS, and two were concurrent. Of these patients with Castleman's Disease, one was resected and the other two were not. Two cases were unicentric, and one was multicentric. First-line systemic chemotherapy was most often gemcitabine and docetaxel, with 9/40 patients receiving this regimen. Ifosfamide and doxorubicin were utilized in 3/40 patients. 2/4 patients had received doxorubicin alone. 2/4 patients had received CHOP. The response rate for patients with gemcitabine and docetaxel was complete response for 2/9 (22%) patients, partial response for 2/9 (22%), stable disease for 2/9 (22%), progressive disease for 1/9 (11%), and missing for 2/9 (22%), giving an overall response rate of 67%. For ifosfamide and doxorubicin, one patient had partial response (33%), another had stable disease (33%), and the last patient's data was missing (33%), adding up to a 66% overall response rate. For CHOP, one patient had progressive disease, and the other had partial response. For doxorubicin, both patients had stable disease. At a median follow-up of 29.5 months (IQR 9.2-75.2 months), the median OS was 160.68 months for the group with both nodal and extranodal disease versus 39.95 months for the extranodal disease-only group. The median OS of the nodal disease alone was not reached, with an estimated 2-year OS of 75%. To evaluate the impact of various primary therapies on outcomes in patients with advanced disease, we conducted a survival analysis by therapy used (no treatment, radiation, surgical resection, and systemic chemotherapy). Patients receiving no treatment had a median survival time of 28.9 months, while those treated with radiation had a median survival time of 19.3 months. Patients undergoing surgical resection had an undetermined median survival time, but notably, 80% were alive at the end of the time period analyzed in this study with a median follow-up time of 60.7 months. Those receiving systemic chemotherapy had a median survival time of 30.7 months. Conclusions: This project is one of the largest known single-center studies dedicated to FDCS. We show that the incidence of preceding or concurrent Castleman's Disease is relatively low. Gemcitabine and docetaxel was the most utilized chemotherapy regimen, but there weren't enough data to conclude if this regimen had a better response rate compared to others. Surgical resection of advanced disease is associated with superior outcomes. When systemic therapy is needed, the median survival was lower.

Background Clonal hematopoiesis (CH) is defined by somatic mutations in hematopoietic stem cells, often conferring a selection advantage based on clonal selection pressures. CH in DNA Damage Response and Repair (DDR, e.g. TP53, PPM1D) genes are frequent in individuals exposed to chemotherapy and radiation (chemo/XRT). In metastatic prostate cancer (mPC) patients, the prevalence of CH is estimated at 57% and is increased among those with prior exposure to chemo or XRT. In these patients, the use of radiotheranostics is becoming more prevalent and are now being tested in earlier lines of therapy. We have identified an increase in DDR-somatic variants post lutetium-177-PSMA, raising concern for long term hematologic safety. Here, we evaluate the spectrum of CH and CCUS (clonal cytopenias of undetermined significance) in mPC patients, prior to receiving radioisotope therapies. Methods We performed error corrected next-generation sequencing (NGS) on peripheral blood samples from 67 mPC patients enrolled in the Prostate Cancer Medically Optimized Genome Enhanced Therapy Study (PROMOTE) study (NCT #01953640). All patients enrolled also had whole exome sequencing (WES) performed on initial metastatic biopsies and on whole blood for germline genotyping. Somatic variants with a variant allele fraction (VAF) ≥0.5% were considered as CH, using standard bioinformatic variant calling algorithms. Results The median age at NGS was 74.4 years (range, 58.4-92.3). While all patients received androgen deprivation therapy (ADT) +/- androgen receptor pathway inhibitor (ARPI), 67.2% (n=45, pelvic XRT- 35, palliative XRT- 10) received prior XRT and 3% (n=2) received prior docetaxel. No patients in this cohort received prior platinum or PARP inhibitor. Of those treated with XRT or chemo, the median time from first exposure to CH sample collection was 4.1yrs (range, 0.12-29.6) and 2.3yrs (range, 0.6-4.0), respectively. Of the 67 patients, we identified a total of 111 pathogenic variants in 59 (88.1%) patients. We compared our NGS data to the germline data and tumor for each patient (All samples obtained at the same time point; Wang et al 2018). Our analysis excluded 2 ATM variants likely to be germline, and 1 TP53 variant likely to be tumor-derived. Each patient had at least one somatic variant, with a median of 2 variants (range, 1-6The median CH VAF was 1.8% (range, 0.5-50.2) with 91.0% of alterations detected at a VAF of <10%. Specific somatic variants, presence/absence of CH, number of variants, nor VAF was associated with age, prior chemo, or XRT exposures. At time of NGS, 54% of patients were anemic (hgb <13g/dL), 7% were thrombocytopenic (platelets <135 x109), 6% were leukopenic (WBC <3 x 109), and no patients were neutropenic (ANC <1 x109). Persistent cytopenias, lasting >3months, were present in 25% (n=17) of patients; however, bone marrow biopsies (BMB) were performed only in 6% (n=4). Three (75%) of these 4 patients had mPC infiltration in the BM, and 1 (25%) had mild dysplasia not meeting criteria for MDS but meeting criteria for CCUS (CHEK2 somatic variant). At last follow-up, there were no patients formally diagnosed to have myeloid neoplasm (MN). Median overall survival (OS) from prostate cancer diagnosis was 8.6yrs (range, 1.4-28.4). With a median follow up of 2.2yrs (range 0.1-10.8) after CH testing, 3.0% (n=2) were alive, with most deaths occurring due to mPC. The presence of CH did not impact overall survival (OS), however, presence of cytopenias at the time of NGS testing was associated with worse outcomes (median OS 2.5yrs vs 1.2 yrs., p=0.025). Conclusions We define the landscape of CH mutations in mPC patients predominantly treated with ADT/ARPI and XRT, demonstrating that DNMT3A, TET2, PPM1D and ASXL1 are frequently mutated (88%) and largely subclonal (91% with VAF ≤10%). While 25% of these patients had cytopenias, with cytopenias negatively impacting survival, due to inadequate BM biopsy work up, the true prevalence of CCUS and MN could not be estimated. Given the advancement of genotoxic therapies and the high prevalence of subclonal CH in mPC, future studies investigating CH as a predictive biomarker of hematological dysfunction are much needed.