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Introduction: Next-generation sequencing (NGS) represents a promising modality for measurable residual disease (MRD) testing in patients with acute myeloid leukemia (AML), but systematic efforts are required to define the appropriate targets, test characteristics, and clinical implications. We recently reported that detection of persistent NPM1 or FLT3 internal tandem duplication (ITD) mutations in adults with AML in first complete remission (CR1) prior to allogeneic hematopoietic cell transplantation (alloHCT) is associated with increased relapse and death compared with those testing negative (JAMA 2023, PMID: 36881031). FLT3 tyrosine kinase domain (TKD) variants are present in 7-10% of adult patients with AML but the utility of this target for AML MRD testing in CR1 prior to alloHCT was previously unknown. Methods: Patients aged 18 or older who underwent alloHCT for AML in CR1 between 2013 and 2019 reported to have a FLT3-TKD variant at diagnosis and a pre-conditioning remission blood sample available in the CIBMTR biorepository were eligible for this study. Single-amplicon NGS (SA-NGS) library generation utilizing UMI-tagged primers targeting the D835 and I836 codons of FLT3 was performed on 400ng genomic DNA sequenced with unique dual indices, with error-corrected variant calling. Primary outcomes were overall survival (OS) and cumulative incidence of relapse (CIR). Secondary outcomes were relapse-free survival (RFS) and non-relapse mortality (NRM), with NRM being considered as a competing risk. Results: A total of351 patients met inclusion criteria for this study, and 342 (97.4%) had sufficient DNA for SA-NGS and were analyzed for clinical outcomes. Of these patients, 81 (23.7%) experienced relapse at a median of 5 months post-alloHCT. Using the current ELN-recommended variant allele fraction (VAF) threshold of 0.1% for NGS-based AML MRD, 14 patients (4.1%) tested positive. Patients with FLT3-TKD MRD VAF≥0.1% experienced higher rates of relapse (73.8% vs. 20.5%, p < 0.0001) and decreased OS (11.4% vs. 66.8%, p < 0.001) compared to VAF<0.1%. The highly sensitive SA-NGS method allowed for exploration to determine if a deeper VAF threshold of 0.01% (previously validated for NPM1 and FLT3-ITD in the Pre-MEASURE study) was prognostic for FLT3-TKD as an MRD target. This led to an additional 20 patients being reclassified as positive (n = 34 with VAF above 0.01%, =9.9%). However, there was no significant difference in CIR (33.6% vs. 19.7%, p = 0.089) or OS (65.2% vs. 66.9%, p = 0.267) between patients with 0.01%≤VAF<0.1% and VAF<0.01% ( Figure). Out of 28 SA-NGS positive calls, 6 could not be validated by orthogonal digital droplet PCR testing, and interestingly, none of those 6 patients experienced relapse. Site-reported pre-transplant remission multiparametric flow cytometry (MFC) was available for 335 patients (98%). Results of MFC were not associated with differences in CIR (HR 1.2, 95% CI 0.52 - 2.76, p = 0.67) or OS (HR 0.78, 95% CI 0.34 - 1.77, p = 0.551).In multivariable analysis, FLT3-TKD NGS-MRD VAF≥0.1% remained prognostic for CIR (HR 6.1, 95% CI 3.1 - 12.0, p < 0.001) and OS (HR 3.2, 95% CI 1.7 - 5.9, p < 0.001). Conclusions: Detectable persistence of FLT3-TKD variants in blood from AML patients in first remission prior to first alloHCT is rare, but at a VAF level of 0.1% was strongly associated with increased relapse and death after transplant compared to those testing negative. In contrast to FLT3-ITD NGS-MRD, no evidence was found to support lowering the NGS-MRD VAF threshold from 0.1% to 0.01% for FLT3-TKD. Alternative methodology may further improve NGS-MRD test performance. Site-reported MFC prior to alloHCT did not stratify for post-transplant relapse or survival. Optimal NGS-MRD testing for patients with AML will likely require a multi-target approach and testing for persistence of FLT3-TKD MRD is shown here to represent an important component of this strategy.

Background The therapeutic landscape of mantle cell lymphoma (MCL) has evolved significantly since the early 2000s. We previously reported that a shift in frontline immunochemotherapy choices from 2002−2009 to 2010−2015 was associated with improved event-free survival and overall survival (OS) in both younger (age ≤65) and older (age >65) patients in a prospective Mayo Clinic/University of Iowa cohort (Castellino, Blood Advances, 2022). In addition, we recently reported that changes in treatment for relapsed/refractory (R/R) disease over the last two decades were associated with steady improvements in OS for R/R MCL (Tawfiq, ASH, 2022). In this study, we utilized data from the National Cancer Database (NCDB) to investigate the impact of therapy in the modern era on survival outcomes of patients with MCL in the US since 2004. Methods The NCDB is an outcomes database of more than 1,500 hospital-based cancer registries covering approximately 70% of newly diagnosed cancers in the US. The latest version of NCDB was used to identify patients with newly diagnosed MCL from 2004 to 2020. Three treatment eras were defined as Era 1 (2004−2009), Era 2 (2010−2014), and Era 3 (2015−2020), based on immunochemotherapy changes (from Era 1 to Era 2) and increased access to novel agents such as Bruton's tyrosine kinase (BTK) inhibitors (from Era 2 to Era 3). Overall survival between different eras was stratified and analyzed based on 3 age groups: <65, 65−79, and ≥80 years. Survival analysis was performed using the Kaplan-Meier method and all Cox proportional hazards models were adjusted for age and sex. Results A total of 32,746 patients with newly diagnosed MCL was identified, 12,847 (39.2%) patients were age <65, 14,297 (43.7%) age 65−79, and 5,602 (17.1%) age ≥80. For every age group, the distributions in sex, stage, Charlson-Deyo score, and treatment facility type (academic vs non-academic) were largely similar between eras. As expected, the median OS was significantly worse for patients age ≥80 years (19.8 months) compared to patients age 65-79 years (60.9 months) and patients age <65 years (143.9 months; p <0.001). In patients age <65 years, OS in Era 2 was improved when compared to Era 1, with a 5-year OS rate of 72.1% vs 67.6% (logrank p<0.001) (Figure 1) and an age- and sex-adjusted hazard ratio (HR) of 0.83 (95% CI 0.78−0.89, p<0.001). OS in Era 3 was similar to that in Era 2, with a 5-year OS rate of 72.2% vs 72.1% (logrank p=0.61) and an age- and sex-adjusted HR of 0.97 (95% CI 0.89−1.06, p=0.51). In patients age 65-79 years, similar trends in OS changes between eras were observed. The 5-year OS rate in Era 1, Era 2, and Era 3 was 43.3%, 52.8%, and 54.9%, respectively (p<0.001 comparing Era 2 vs Era 1, and p=0.05 comparing Era 3 vs Era 2). Age- and sex-adjusted HR was 0.83 (95% CI 0.78−0.87, p<0.001) comparing Era 2 vs Era 1 and 0.95 (95% CI 0.89−1.01, p=0.07) comparing Era 3 vs Era 2. In patients age ≥80 years, the improvement in OS from Era 1 to Era 2 was less prominent than other age groups. The 5-year OS rate was 22.9% vs 19.5% (p=0.03), and age- and sex-adjusted HR was 0.88 (95% CI 0.81−0.94, p<0.001). OS in Era 3 vs Era 2 was similar, with a 5-year OS rate of 23.1% vs 22.9% (logrank p=0.79) and an age- and sex-adjusted HR of 0.98 (95% CI 0.91−1.06, p=0.67). Conclusions This large NCDB study demonstrated that survival of patients with newly diagnosed MCL has improved over the last two decades. The results are consistent with our Mayo Clinic/University of Iowa prospective cohort study and confirm an improved OS after 2010, which was most likely driven by both frontline immunochemotherapy changes and better access to novel agents for R/R disease. The 5-year OS in patients diagnosed in 2015−2020 did not appear to be superior to those in 2010−2014, despite presumably having better access to novel agents such as BTK inhibitors in the R/R setting. This lack of a difference in OS may be partially due to short follow-up, but may also suggest that further improvement in frontline therapies by incorporating novel agents may be required to improve OS. The OS of patients age ≥80 years is limited and has only minimally improved after 2010, highlighting a significant unmet need for therapies with improved tolerability and efficacy in this age group.

Background: Patients (pts) receiving FDA-approved chimeric antigen receptor T-cell (CAR-T) therapy or Bispecific antibody Teclistamab (Tec) are commonly managed in the inpatient setting given the common adverse events such as cytokine release syndrome (CRS) and immune cell-associated neurotoxicity syndrome ICANS. We have previously reported that hospital-based outpatient (HBO) management of pts receiving CAR-T is feasible and safe (Bansal et al, ASH2022). In 2023, HBO management at our institution began incorporating home health visits and management of grade 1 CRS in outpatient setting for select pts receiving standard of care (SOC) CAR-T. Here, we report outcomes of our updated practice. Methods: We retrospectively analyzed medical records and remote monitoring data of adult pts who received SOC CAR-T or Tec between 10/2020 and 7/2023 at Mayo Clinic, Rochester under an IRB approved protocol. Results: In 3/2023, pts deemed to be low risk for severe CRS (fever onset >= 3 days from infusion, CRP<100) received HBO management for grade 1 CRS, including outpatient administration of tocilizumab. If CRS improved or resolved, outpatient monitoring was continued. If CRS persisted within the observation period on HBO, pts were admitted. Recurrent CRS after the first episode were all managed inpatient. Nine pts met these criteria for HBO CRS management and their outcomes were compared to those who received initial inpatient (INPT) CRS management (INPT, n=17) during the same timeframe, as well as the outcome of 164 pts who had CRS management INPT prior to our practice change (Table 1). Two-third of the pts with initial management of CRS outpatient did not require hospitalization. Median time to hospitalization trended later than those managed inpatient at the onset of CRS. The duration of hospitalization was comparable for all pts admitted between initial HBO and INPT CRS management. However with fewer admissions in the initial CRS HBO group, the average hospitalization days (LOS) per patient treated for that group was lower compared to initial INPT CRS management. Data on additional pts will be presented at ASH. In 1/2023, pts on RPM with no ongoing CRS symptoms, no language barriers, and no compliance concerns received home health visits during weeks 3 and 4 post CAR-T infusion in place of clinic visits on HBO. Home health visit team communicated with HBO staff to review assessment and plan. Changes in HBO utilization will be presented. Finally, 24 pts received 223 Tec infusions on HBO. Median age was 66 years, 15 (61%) were males, 9 (38%) had high risk cytogenetics. The median prior lines of therapy was 5. Among these pts, 220/223 (99%) doses were performed on HBO and 204/220 (93%) infusions never required admission for management. Twenty pts enrolled in RPM (Figure 1). An average of 2 alerts were generated per patient during the 2 week period and median time from infusion to alert was 1.5 days. Majority of alerts were resolved over a phone call and only 13/114 (11%) alerts required a physician visit/hospital admission. Of the 16 Tec infusions resulting in admission, 4/16 (25%) required re-admission resulting in a total of 20 hospitalizations. Admissions mostly occurred during step-up dosing (18/20; 90%). Most common reason for first admission was fever (13/16, 85%) and median time to admission was 1 day from infusion. Median LOS was 1.5 days (range, 0-12). In terms of CRS, majority were Grade 1 (12/13, 93%) which were managed with steroids (dexamethasone/ prednisone) alone. One patient had CRS grade 4 event, in the setting of concurrent decompensation during dialysis, and was treated with steroids, tocilizumab, vasopressor, CRRT, thoracentesis, intubation and mechanical ventilation. The rate of second CRS event after management of first CRS with steroid (dexamethasone/ prednisone) was 15% (2/13). These second CRS episodes also resolved with steroid alone. Data on additional pts receiving Tec will be presented at ASH. Conclusion: Our data showed that additional advances in outpatient practice, including initial outpatient management of CRS and outpatient administration of Tec step up dosing are feasible, safe and reduce hospital resource utilization.

Background:Patients with R/R CLL/SLL who experience intolerance to or disease progression after Bruton tyrosine kinase inhibitor (BTKi) and venetoclax treatment have no established standard of care and poor outcomes, indicating a critical unmet need. Liso-cel, an autologous, CD19-directed, 4-1BB CAR T cell product, has demonstrated efficacy in large B-cell lymphoma and CLL/SLL. In the primary analysis of the phase 1/2, single-arm, multicenter TRANSCEND CLL 004 (NCT03331198) study, a single administration of liso-cel demonstrated rapid, deep, and durable responses and a manageable safety profile in patients with R/R CLL/SLL, including those with progression on previous BTKi and venetoclax failure (Siddiqi T, et al. Lancet 2023). The primary endpoint was met in the prespecified subset of efficacy-evaluable patients with disease progression on BTKi and venetoclax failure (primary efficacy analysis set [PEAS]) at a target dose of 100 × 10 6 CAR + T cells (null hypothesis: ≤ 5%) with the rate of complete response/remission (CR) and CR with incomplete marrow recovery (CRi) by an independent review committee (IRC) per 2018 International Workshop on CLL (iwCLL) criteria at 18.4% ( P = 0.0006). Here we report results from TRANSCEND CLL 004 with a median follow-up of 23.5 months. Methods: Patients must have received ≥ 2 prior lines of therapy, including a BTKi. Eligible patients received liso-cel at a target dose of either 50 × 10 6 (dose level [DL] 1) or 100 × 10 6 (DL2) CAR + T cells after lymphodepleting chemotherapy. The primary endpoint was CR/CRi in the PEAS at DL2. Key secondary endpoints were ORR and rate of undetectable MRD (uMRD; 10 −4 by next-generation sequencing) in blood. All null hypotheses were tested at the primary analysis and not retested in this analysis. Results:Of 137 leukapheresed patients, 118 received liso-cel (safety set), 97 (DL1 = 9; DL2 = 88) were efficacy evaluable, and 54 (DL1 = 4; DL2 = 50) were in the PEAS. In the safety set, median (range) age was 65 years (49-82), 83% had high-risk cytogenetics (del[17p], 42%; TP53 mutation, 47%; unmuted immunoglobulin heavy-chain variable gene, 47%; ≥ 3 chromosomal aberrations, 61%), median (range) lines of prior therapy was 5 (2-14), and all patients had prior BTKi. As of data cutoff (February 28, 2023), median (range) on-study follow-up was 23.5 months (0.4-59.6) for the safety set. In the PEAS at DL2, CR/CRi rate was 20% (95% CI, 10.0-33.7; Table 1). ORR was 44% (95% CI, 30.0-58.7). One patient who had best overall response (BOR) of partial response/remission (PR) at primary analysis had deepened to CR/CRi at 18 months without any additional therapy. Of 9 patients who had BOR of CR/CRi at the primary analysis, 8 had ongoing CR/CRi and 1 completed the study with the last assessment as CR/CRi. The uMRD rate was 64% (95% CI, 49.2-77.1) in blood and 60% (95% CI, 45.2-73.6) in marrow. Median (95% CI) duration of response was 35.3 months (12.4-not reached [NR]) and median duration of CR/CRi was NR. Median (95% CI) PFS was 11.9 months (5.7-26.2). Median (95% CI) OS was 30.3 months (15.0-NR). The efficacy outcomes were similar in the full population at DL2. Of 16 patients who had BOR of CR/CRi at primary analysis, 10 had ongoing CR/CRi. In the safety set, rates of any-grade and grade ≥ 3 treatment-emergent AEs were similar across age groups (Table 2). The rate of any-grade cytokine release syndrome (CRS) was 85% (grade 3, 8%; no grade 4/5) and neurological events (NE) was 45% (grade 3, 18%; grade 4, 1%; no grade 5); 69% received tocilizumab and/or corticosteroids for CRS/NEs. Median (range) time to onset and resolution was 4 days (1-18) and 6 days (2-37) for CRS and 7 days (1-21) and 7 days (1-83) for NEs, respectively. Prolonged cytopenia (grade ≥ 3 at Day 30 after liso-cel infusion), grade ≥ 3 infections, hypogammaglobulinemia, tumor lysis syndrome, second primary malignancy, and macrophage activation syndrome occurred in 54%, 18%, 15%, 11%, 9%, and 3%, respectively. Forty-five (33%) of 137 leukapheresed patients died after liso-cel infusion (disease progression, n = 27 [20%]; AE, n = 6 [4%]; other reasons, n = 12 [9%]). Conclusions: With longer follow-up, liso-cel continued to demonstrate durable CR/CRi, high uMRD rates, and a manageable safety profile in patients with heavily pretreated, high-risk R/R CLL/SLL. The safety results from longer follow-up were similar to those reported in the primary analysis with no new safety signals and were consistent across age groups.

Introduction: Detection of measurable residual disease (MRD) prior to allogeneic hematopoietic cell transplant (alloHCT) in patients with acute myeloid leukemia (AML) in remission is associated with increased relapse and inferior survival after transplant. We recently reported that next-generation sequencing (NGS) detection of mutated NPM1 or FLT3-ITD in first complete remission (CR1) blood prior to alloHCT is strongly associated with increased relapse and death (PMID: 36881031). However, the prognostic implications of detecting persistence of other common AML-associated mutations at this treatment landmark remain incompletely defined. Around 20% of patients diagnosed with AML have variants in isocitrate dehydrogenase ( IDH) genes (~7% for IDH1) and clinical outcomes are known to differ due to co-occurrence of other mutations, IDH subtypes, treatment strategies, and patient factors. Studies have examined the relationship between residual IDH1 variants ( IDH1m) in CR and subsequent clinical outcomes, but definitive standardized evidence to inform decision-making for the clinical utility of IDH1m as a target for AML MRD testing was not previously available. Methods: Adult patients undergoing alloHCT for IDH1 mutated AML in CR1 at CIBMTR sites in the USA between 2013-2019 were eligible for the study if remission blood sample collected within 100 days before alloHCT and outcome data were available. Ultrasensitive error-corrected NGS (NGS-MRD) targeting IDH1, NPM1, and FLT3 genes was performed on DNA from pre-conditioning blood to identify residual variants. Detected IDH1m were validated by digital droplet PCR (ddPCR). The day of transplant was considered as day 0. Median follow-up time was calculated for censored patients. Overall survival (OS) was estimated using Kaplan-Meier (log-rank tests) and Cox proportional hazards models (forward selection); cumulative incidence of relapse was examined using Fine-Gray regression models with non-relapse mortality as a competing risk. Results: A total of 148 patients were included in the study, with a median follow-up time of 24 months. Relapse was observed in 37 (25%) patients, with the majority occurring within 1 year after alloHCT (n = 28, 76%). Pre-transplant flow cytometry results were reported by the transplant centers for 97% of patients (n = 144), but no statistically significant differences in clinical outcomes were observed between the positive and negative groups (OS: p = 0.3; relapse: p = 0.07). 53 patients (36%) tested positive for IDH1m persistence in CR1, with a 100% validation rate by ddPCR for variants with an orthogonal assay available. Logistic regression indicated that IDH1m persistence in remission was more likely to occur in patients older than 40 years (OR: 1.02 with every 1-year increase after 40, p = 0.04). Clinical outcomes showed no statistically significant difference between the pre-alloHCT IDH1m positive and negative groups (Figure 1A), and this remained true after further subgroup analysis by age. The variant allele fraction (VAF) of the residual IDH1m ranged from 0.09% to 48.5% (median: 1.5%), and no differences in clinical outcomes were observed when stratifying by high (≥2.5%) or low VAF (<2.5%). Among patients with co-mutated NPM1 and/or FLT3-ITD at baseline (n=69), those with residual mutated NPM1 and/or FLT3-ITD in pre-transplant remission had significantly higher rates of relapse compared to those with residual IDH1m only or NGS-negative groups (p = 0.01, Figure 1B). The cohort excluding patients with co-mutated NPM1 and/or FLT3-ITD did not show any significant clinical outcome differences based on IDH1m persistence. Conditioning intensity did not show an association with clinical outcomes, and multivariable analysis for overall survival and relapse did not identify residual IDH1m as an important marker. Conclusion: Detection of persistent IDH1 variants in the blood of adult patients with AML in CR1 prior to first alloHCT is common, but not associated with increased relapse or death after transplant compared with those testing negative. For those patients with IDH1 mutated AML co-mutated with either NPM1 and/or FLT3-ITD, detection of persistent NPM1 and/or FLT3-ITD was associated with higher rates of relapse. These findings, from the largest study to date, do not support the detection of isolated IDH1 variants in CR1 blood prior to alloHCT as evidence of AML MRD or increased post-transplant relapse risk.

Background Limited stage (stage I−II) disease is an uncommon presentation of mantle cell lymphoma (MCL), and its optimal management remains controversial. A British Columbia study (Leitch, Ann Oncol, 2003) and a Surveillance, Epidemiology and End Results (SEER) study (Murthy, Clin Lymphoma Myeloma Leuk, 2014) suggested the importance of radiotherapy (RT). A National Cancer Database (NCDB) study in the pre-BTK inhibitor (BTKi) era showed that chemotherapy (Chemo) plus RT (Chemo+RT) improved overall survival (OS) compared to Chemo or RT alone (Gill, Int J Radiat Oncol Biol Phys, 2015). However, a retrospective International Lymphoma Radiation Oncology Group study (Dabaja, Ann Oncol, 2017) reported comparable OS with Chemo+RT vs Chemo or RT alone. The potential differences in OS with different frontline therapy modalities may be modified by subsequent therapies for relapsed or refractory (R/R) disease. In this study, we used the NCDB data to analyze frontline treatment patterns and outcomes of limited stage MCL in the pre-BTKi vs BTKi eras. Methods The NCDB was queried to identify patients with stage I−II MCL diagnosed in 2004−2020. Because the first BTKi ibrutinib was approved by the FDA for R/R MCL in November 2013, we defined 2004−2013 as pre-BTKi era and 2014−2020 as BTKi era. Frontline treatment modalities were categorized to RT alone, Chemo alone, or Chemo+RT. Survival analysis was performed using the Kaplan-Meier method and the Cox proportional hazards model. Results Among 32,746 patients with newly diagnosed MCL in 2004−2020, 3,836 (11.7%) presented with stage I−II disease, with 2,428 having treatment information available. For patients diagnosed in the pre-BTKi era (n = 2005), 195 (9.7%) received RT alone, 1472 (73.4%) received Chemo alone, and 338 (16.9%) received Chemo+RT. For patients diagnosed in the BTKi era (n = 423), 45 (10.6%) received RT alone, 320 (75.7%) received Chemo alone, and 58 (13.7%) received Chemo+RT. Patients in the RT alone group were older (P <0.001) and had more females (P <0.001), but there were no statistically significant differences in Charlson-Deyo score, international prognostic index, or treating facility type (academic vs non-academic). For patients with stage I disease, in the pre-BTKi era, patients treated with Chemo+RT (n = 182) had improved OS compared to those treated with RT alone (n = 141) or Chemo alone (n = 647), with a 5-year OS of 75.4% vs 71.8% vs 61.4% (P <0.001). Similar results were observed in the BTKi-era, with a 5-year OS of 83.6% vs 69.5% vs 62.9% (P <0.001) for patients treated with Chemo+RT (n = 31), RT alone (n = 30), or Chemo alone (n = 130), respectively. After adjusting for age and sex, Chemo+RT was associated with improved OS compared to Chemo alone (pre-BTKi era, HR = 0.59, 95% CI = 0.46−0.75, P <0.001; BTKi era, HR = 0.34, 95% CI = 0.14−0.79, P = 0.013), but not compared to RT alone (pre-BTKi era, HR = 0.62, 95% CI = 0.23−1.68, P = 0.343; BTKi era, HR = 0.77, 95% CI = 0.56−1.05, P = 0.10) (Figure 1A). For patients with stage II disease, in the pre-BTKi era, patients treated with Chemo+RT (n = 156) had improved OS compared to those treated with RT alone (n = 54) or Chemo alone (n = 825), with a 5-year OS of 70.0% vs 47.3% vs 58.4% (P <0.001). In the BTKi-era, patients treated with Chemo+RT (n = 27) or RT alone (n = 15) both had improved OS compared to those treated with Chemo alone (n = 190), with a 5-year OS of 77.2% vs 78.8% vs 61.9% (P = 0.004) . After adjusting for age and sex, Chemo+RT was associated with improved OS compared to Chemo alone in BTKi era only (pre-BTKi era, HR = 0.85, 95% CI = 0.67−1.07, P = 0.165; BTKi era, HR = 0.49, 95% CI = 0.25−0.95, P = 0.034), but not compared to RT alone (pre-BTKi era, HR = 0.78, 95% CI = 0.53−1.13, P = 0.185; BTKi era, HR = 0.97, 95% CI = 0.35−2.67, P = 0.952) (Figure 1B). Conclusions Treatment pattern for limited stage MCL has not changed significantly from the pre-BTKi era to the BTKi era, with approximately 15% of patients receiving Chemo+RT, 10% RT alone and 75% Chemo alone. In the BTKi era, Chemo+RT appeared to be associated with better OS compared to Chemo alone but not compared to RT alone. Interpretation of the results requires caution because (1) patient numbers are small in Chemo+RT and RT alone groups, (2) longer follow-up may be needed, and (3) selection of therapy was not random, eg, patients receiving Chemo alone may have had higher disease burden such as bulky disease and/or non-contiguous stage II involvement but these details are not available in NCDB.

Background: A subset of follicular lymphoma (FL) patients will experience a ‘high-risk defining event’ (HRDE) that portends poor survival due to early progression of disease or transformation to diffuse large B cell lymphoma (TFL). Progression of disease within 24 months (POD24) from front-line immunochemotherapy (ICT) identifies patients with a subsequent five-year OS of 50% compared to a reference group of 90% (Casulo et al. JCO 2015). Although a robust surrogate endpoint for OS in clinical trials (Casulo et al. Blood 2022), it remains to be established if the OS of patents is influenced by the nature of the HRDE. In this study, we examined whether characteristics and clinical trajectory of those with relapsed/progressive FL is the same as that of patients experiencing TFL. Methods: We conducted an international retrospective analysis of newly diagnosed FL patients requiring treatment across 14 academic centres between 2002 and 2021 in the era of rituximab and PET-CT staging. Patients were included with grade 1-3A FL requiring first-line (1L) treatment (ICT, rituximab monotherapy or radiotherapy). We excluded patients with untreated FL, de novo TFL and those with <24 months follow up provided they did not experience a HRDE. Baseline clinical, imaging and laboratory values, treatment details and outcomes were collected. We defined HRDE groups as persistent (relapse or progression) FL within 24 months of 1L treatment (FL24), early TFL (<24 months of 1L treatment) or late TFL (>24 months of 1L treatment). Patients not experiencing a HRDE formed the FL reference group. Landmark overall survival (OS) analysis was performed by Cox regression using risk status as a time-varying covariate for time of HRDE. For the FL reference group, landmark was defined at 24 months after 1L treatment. Results: 501 patients met the inclusion criteria and were categorised as: reference FL (n=378), FL24 (n=50), early TFL (n=28), late TFL (n=15). 24 patients who died within 24 months of 1L treatment without documentation of preceding HRDE and were omitted. Median follow up for patients alive beyond 24 months was 5.1 years. Median age at diagnosis was 60 years, 91% had ECOG performance status 0-1 and 38% were high-risk (>3) FLIPI. 1L chemotherapy regimens included: bendamustine (59%), CHOP (24%), CVP (8%), other (9%); a majority received rituximab (80%) vs obinutuzumab (20%). Maintenance therapy was used in 54% of pts. Expectedly, those experiencing HRDE had an inferior OS compared to the reference group (HR 5.23, p<0.001)(Figure 1). However, among HRDE group, median OS significantly differed: early TFL patients (3.0 yrs) and FL24 (12.6yrs)(HR 2.27, p=0.02) (Table 1). There was no difference in OS after HRDE between early TFL and late TFL ( p=0.81). Biopsy was performed in 84% of TFL cases with no difference in OS between biopsy-proven vs clinically suspected cases ( p=0.23). Multivariate OS analysis assessing HRDE and treatment demonstrated no significant interaction between HRDE group and 1L chemotherapy ( p=0.52), monoclonal antibody ( p=0.29) or maintenance therapy ( p=0.27). Several established prognostic features at baseline were enriched in patients who went on to experience HRDE including: ECOG >1 ( p<0.001), raised LDH ( p<0.001), advanced-stage disease (( p<0.011) and high risk FLIPI ( p=0.005). Baseline FDG-PET was available in 259 patients. Adverse PET metrics were enriched in only early TFL, and not FL24 or late TFL patients, including high SUV max( p=0.009), total metabolic tumor volume ( p=0.015) and total lesional glycolysis ( p=0.01). Conclusions: HRDEs after 1L treatment are associated with inferior OS in FL compared with standard-risk patients. Unlike POD24, this study demonstrates disparate clinical outcomes between patients experiencing early progression with persistent FL and those experiencing TFL. Adverse metabolic characteristics on baseline FDG-PET also suggest biological distinction between HRDE subsets. These findings have important implications for epidemiological studies, biomarker development and clinical trials aiming to improve outcomes in this underserved high-risk FL cohort.

Background: We previously reported that treatment with the anti-CD30 antibody-drug conjugate brentuximab vedotin (BV) in combination with the checkpoint inhibitors targeting CTLA-4 and/or PD-1 (ipilimumab (I) and nivolumab (N)) led to high overall response rates (ORR) and complete response (CR) rates in relapsed/refractory (R/R) Hodgkin's lymphoma patients in a Phase 1 ECOG-ACRIN sponsored clinical trial. As previously presented in the Phase 1 component of NCT01896999 (E4412), the ORR for the treatment arms were: BV+I 76%, BV+N 89%, and BV+I+N 82%, with CR rates of 57%, 61%, and 73% across the groups, respectively. This suggested that not all patients who responded derived equal benefit. Moreover, with a median follow-up of 2.24 years, the PFS of 1.1 year, NR, and 2.49 years across the groups suggest that even some patients who achieved CR progressed on or subsequent to treatment. Currently biomarkers have no ability to predict which patients will maximally benefit from these therapies. We investigated blood-based immune biomarkers mechanistically across all cohorts which may explain differential responses and guide future treatment decisions for R/R HL patients. Methods: Peripheral blood plasma for 54 of 61 (89%) patients evaluable for response was collected at up to 4 time points and tested for 92 immuno-oncology soluble analytes with Olink proximity extension assay and for antibody titers to 20 known tumor antigens by ELISA. Matching peripheral blood mononuclear cells (PBMC) were analyzed by CyTOF mass cytometry for major immune cell subsets and marker surface expression, and for T cell receptor diversity by Immunoseq®. Mixed effect linear models were used to identify significantly associated changes (P<0.05) related to treatment longitudinally within groups and to ORR between groups. Results: Analysis of plasma demonstrated durable increase in soluble plasma PD-1 and decreases in CCL17, ANGPT2, MMP12, IL13, and CXCL13 in N-containing regimens, and higher GZMA and CAIX in BV+I (P<0.05). Despite baseline heterogeneity in PBMC composition, we found durable increases in plasmacytoid dendritic cells (pDC) after N-containing treatments, and transient increases in plasmablasts and memory B cells, as well as early decreases in naïve CD4+ T cells and neutrophils across treatments. Treatment with BV+I+N demonstrated late increases in neutrophils, and changes in memory B cell markers. Clinical benefit analyses revealed that elevated soluble CD5, ADA, CXCL13, and CCL17 at baseline or after two treatment cycles were associated with worse ORR (P<0.05), and that a module of co-regulated soluble analytes at baseline, including MUC16, was associated with worse progression free survival (PFS) (P<0.05). NY-ESO-1 autoantibodies were more frequent in non-responders, and the top 10% of expanded TCR clonotypes were increased in responders after one treatment cycle (P<0.05). Conclusion: This data reveals differential immune activation based on treatment modality for patients with R/R HL receiving checkpoint-based regimens in combination with an ADC. Our data highlights potential tumor- and immune-derived predictive and pharmacodynamic biomarker candidates of response and resistance. These novel findings have relevance for R/R HL patients receiving immunotherapy and other immunotherapy combinations such as immuno-chemotherapy platforms. Prospective evaluation of these biomarkers in the Phase II component of this study, a randomized comparison of BV+N vs. BV+N+I which has completed adult accrual, is planned. Figure Legend Clinical responders and non-responder patient samples were analyzed using ELISA (auto antibodies), CyTOF (Cell populations), TCRseq (T cell clonality) and Olink (proteomics). The results showed that pDCs, Neutrophils and B-Plasmablasts increased with specific drug combinations independently of clinical response. While T Cell expansion was associated with clinical response, the increase of auto antibodies against NY-ESO-1 and circulating proteins CD5, ADA, MUC16, CXCL13, CXCL9 and CCL17 were associated with worse prognosis

Background: Treatment of chronic lymphocytic leukemia (CLL) has been transformed with targeted therapies including inhibitors of Bruton's tyrosine kinase (BTKi). Currently three covalent BTK inhibitors (cBTKi) are approved for CLL, but most patients eventually relapse, commonly through acquisition of the C481S BTK mutation (Woyach et al. 2014). Pirtobrutinib and nemtabrutinib are non-covalent BTK inhibitors (ncBTKi) developed to target and inhibit C481S mutant BTK. However novel secondary site mutations in BTK, namely T474I and L528W, have been found to confer resistance to both cBTKi and ncBTKi (Wang et al. 2022). Regardless of these mutations, BCR signaling remains intact, suggesting that inhibition of BTK maintains its therapeutic importance. LP-168 is a novel ultra-selective 4 th generation BTKi with an active warhead capable of covalent interaction with WT BTK or non-covalent binding when a BTK C481 mutation is present. Methods: To determine the target selectivity of LP-168 we screened the compound against 468 kinases in the scanMAX Kinase Assay. For validation of covalent binding, dialysis against WT BTK was performed. Primary CLL B cells were isolated by negative selection and treated with LP-168 for all experiments. BCR signaling alterations were assessed via immunoblot to observe changes in target protein phosphorylation. Changes in CLL migration towards CXCL12 or CXCL13 were interrogated by transwell migration. Cytotoxicity towards primary CLL cells was measured via Annexin V/PI flow cytometry with and without HS-5 stromal cell support. Experiments using TMD8 cells were performed following CRISPR modification to insert WT, C481S, or T474I BTK. In vivo survival studies were performed using both the Eμ-TCL1 and Eμ-MTCP1 mouse engraftment models. Results: LP-168 demonstrated selectivity towards BTK with roughly 700-fold selectivity for BTK vs its next off-target. In an enzymatic assay, LP-168 displayed nanomolar potency towards both WT BTK (IC 50=0.11 nM) and C481S BTK (IC 50=1.0 nM). Following 2-hour drugging, LP-168 inhibited BCR signaling in primary CLL B cells at increasing concentrations, demonstrated by reduced phosphorylation of BTK (92%, p<0.0001, n=8) and its immediate downstream target PLCγ2 (41%, p=0.0013, n=8). Migration capacity of primary CLL cells towards CXCL12 and CXCL14 was also found to decrease after 2-hours of treatment with LP-168 (52%, p<0.001, n=10 and 51%, p<0.001, n=10, respectively). After 48 hours of exposure, LP-168 was able to induce cytotoxicity of primary CLL cells alone and in co-culture with HS-5 stromal cells in a dose-dependent manner, with similar or improved efficacy to other BTKi. LP-168 decreased CLL cell production of CCL3 and CCL4 chemokines (CCL3: 93%, p<0.001, n=8; CCL4: 93%, p<0.001, n=8). LP-168 also demonstrated modest cytotoxicity towards TMD8 cells harboring either C481S BTK (24%, p=0.0008 , n=3) or T474I BTK (13%, p=0.0690, n=3), as well as decreased production of CCL3 (C481S: 95%, p<0.0001, n=3; T474I: 99%, p<0.0001, n=3) and CCL4 (C481S: 97%, p<0.0001, n=3; T474I: 98%, p<0.0001, n=3) (Figure 1A). Further, we observed inhibition of downstream BCR signaling in primary CLL B cells harboring C481S via immunoblotting and cytokine production. Finally, to evaluate the in vivo efficacy of LP-168 we tested this compound in both the Eµ-TCL1 and Eµ-MTCP1 models. We treated mice daily via oral gavage and found that 50 mg/kg of LP-168 significantly improved survival in the Eµ-TCL1 model when compared to vehicle (median 51 vs 44 days; p=0.0018) or ibrutinib at 50 mg/kg (median 51 vs 45 days; p=0.0098) and the Eµ-MTCP1 model when compared with vehicle (median 122 vs 62 days; p<0.0001) or ibrutinib at 50 mg/kg (median 122 vs 96 days; p=0.0162) (Figure 1B). Conclusions: Collectively, our data demonstrate that LP-168 is a potent and selective inhibitor of BTK with activity against CLL, even in the presence of mutations that mediate resistance to cBTKi and ncBTKi. These data support the continued preclinical and clinical investigation of LP-168, which is currently being studied in the phase 1 setting of CLL (NCT04775745) and NHL (NCT04993690).

Background: Oncolytic virotherapy, an innovative immunomodulatory therapeutic approach, is currently being investigated for its potential in treating relapsed refractory (R/R) hematologic malignancies. This study focuses on the use of an engineered Vesicular Stomatitis Virus called VSV-IFNβ-NIS, a bullet-shaped rhabdovirus which encodes both interferon beta (IFNβ) and sodium iodine symporter (NIS) with particular tumor cell tropism. Viral IFNβ serves as an indicator of viral proliferation and boosts the host's anti-tumor immune response. This is a phase 1 clinical trial with the identifier NCT03017820, wherein patients (pts) with R/R multiple myeloma (MM), and non-Hodgkin lymphoma (NHL) are treated with a single systemic administration of VSV-IFNβ-NIS. Study Design and Methods: Patient Eligibility Criteria: The Mayo Clinic Institutional Review Board approved the protocol. The study includes adult patients with relapsed or refractory multiple myeloma (MM), or T-cell lymphoma (TCL). For MM or plasmacytoma, patients should have <15% plasma cells and a largest diameter of <5 cm. TCL patients should have a mass <5 cm. Study Design: This is a single-center phase 1 trial aiming to determine the maximum tolerated dose of VSV-IFNβ-NIS in patients with R/R MM, and TCL. Secondary objectives included assessing the safety profile and estimating the clinical response rate of VSV-IFNβ-NIS. Correlative objectives involved monitoring viral replication through plasma IFN-β transgene levels and using SPECT/CT imaging with the NIS gene. Viral genomes were measured through quantitative reverse transcription (qRT) polymerase chain reaction (PCR) of VSV RNA, and any virus shedding was examined in body fluids. The tested doses were 5 × 109 TCID50, 1.7 × 1010, 5 × 1010, and 1.7 × 1011 TCID50. The virus was administered via IV infusion over 30 minutes, and patients received 650 mg acetaminophen and 50 mg diphenhydramine hydrochloride before infusion and every 6 hours for 24 hours to manage fever and hypotension. Two expansion cohorts at DL4 have been added (20 additional PTCL, 10 B-cell lymphoma and histiocytic neoplasms) to obtain additional data on tolerability and efficacy and biomarkers of response in these histologies. Safety and Response Assessments: All patients undergo toxicity evaluation, and adverse events (AEs) assessment using the Common Terminology Criteria for Adverse Events (CTCAE) version 4 criteria, except for cytokine release syndrome (CRS) grading, which follows the 2014 Lee criteria. Dose escalation and tolerability are based on the standard 3+3 phase 1 trial design. Ruxolitinib is added from days 2-5 or day -1 to day 9 depending on the arm to mitigate IFNβ toxicity. Response assessment followed the International Myeloma Working Group criteria for MM and the Lugano Classification for NHL and histiocytic neoplasms. Pharmacodynamic and Pharmacokinetic Analyses: For viremia and viral shedding assessment, RNA is isolated from whole blood, mouth rinse, buccal swabs, and urine samples. Quantitative RT-PCR determined VSV-nucleocapsid (N) RNA copy number, and virus shedding is assessed through coculturing samples on Vero cells. Anti-VSV antibodies are evaluated using the standard plaque reduction neutralization assay. Plasma cytokine levels are measured with a 30-plex human cytokine kit, and human IFN-β levels is quantified using an enzyme-linked immunosorbent assay (ELISA) kit. Statistical Analysis: Incidence of dose-limiting toxicities and AEs are tabulated by dose level (DL). AEs are summarized by type, maximum grade, and duration across patients in each DL. Spearman rank correlation tests are used evaluated correlations between laboratory-based measures, and Wilcoxon rank sum tests compared continuous measures between response groups. Response rates will be summarized by DL and disease group, with estimated response rates and corresponding 95% binomial confidence intervals calculated.