Goldberg, Aaron D.

Abstract Background: Undetectable minimal residual disease (uMRD) at the end of first-line (1L) treatment (tx) with 12-cycles (C) of venetoclax (ven) + obinutuzumab (obin) is associated with prolonged survival for patients (pts) with chronic lymphocytic leukemia (CLL, Al Sawaf et al. Blood 2024). We hypothesized that MRD may be used to guide ven tx duration for CLL pts treated with 1L ven + obin. Methods In this ongoing phase II, multicenter investigator-initiated study, pts receive ven + obin for 1L tx of CLL/small lymphocytic lymphoma (NCT04447768). Eligible pts have a CIRS score of ≤ 6 and require 1L tx per iwCLL 2018 criteria. Pts receive 6 x 28-day C of obin and initiate ven on C1D22. Ven duration is dependent on peripheral blood (PB) MRD status measured by ClonoSeq next generation sequencing. At C7, pts undergo MRD testing. Pts uMRD6 (<10-6 sensitivity) at both C7 and C9 dc ven after 9C and enter treatment free observation (TFO). Pts with detectable MRD6 (dMRD6) at C7 undergo repeat testing at C12; if uMRD5 (<10-5) pts dc ven after 12C. Pts dMRD5 at C12 continue ven for an additional 12C (24C total) prior to TFO. The primary study endpoint is 36-month PFS; the unpromising rate is set at 82% and will be tested by a nonparametric survival estimate (Kaplan-Meier) along with Greenwood's formula. RNA sequencing (RNAseq) was performed pre-tx on patient bone marrow (or PB if inaspirable) samples. Unsupervised clustering using machine learning (ML) based on consensus nonnegative matrix factorization was applied to the most variable genes to identify patient clusters. Clusters were then biologically characterized by gene signature scoring using xCell algorithm and assessed for association with uMRD6 at C7 using a Fisher exact test. Results Baseline characteristics of the 100 pts who initiated tx include: median age 58 (range 34-81); 71% male, 90% White, 3% Black and 2% Asian, 5% unknown; 49% IGHV unmutated, 16% TP53 mutation, 8% del17p (previously reported, Roeker et al. ASH 2024). 3 pts stopped tx prior to C7. 51 pts were uMRD6 at C7 and C9 and completed 9C ven. 46 pts were dMRD6 at C7; 6 pts stopped tx outside of meeting protocol requirements and are included in intention-to-treat (IIT) analyses. 32 pts were uMRD5 at C12 and dc ven after 12C. 8 pts were dMRD5 at C12: 5 continued ven per protocol (3 completed 24C ven, 2 ongoing tx as of 15 May 2025 data cut-off), 2 stopped ven outside of protocol requirements (included in ITT analyses), and 1 pt withdrew consent. At a median follow-up of 35 months, the 36-month PFS rate is 90% (95% CI: 84%, 97%). 36-month OS is 94% (95% CI: 89%, 99%). Landmark PFS analyses from EOT were performed for pts who dc ven after 9C due to uMRD6 (24-month PFS 92%, 95% CI: 85, 100%, n=51) and pts who dc ven after 12C due to uMRD5 (24-month PFS 96%, 95% CI: 89%, 100%, n=32). For pts dc ven after 9C due to uMRD6 (n=51), PB MRD at 12C after EOT was: 59% uMRD6, 12% uMRD5, 4% uMRD4, 8% dMRD4 and 18% unknown. For pts dc ven after 12C due to uMRD5 status (n=32), PB MRD at 12C following EOT was: 9% uMRD6, 31% uMRD5, 9% uMRD4, 25% dMRD4 and 25% unknown. Of the 5 pts with PD, 3 pts have had Richter Transformation to diffuse large B-cell lymphoma (all uMRD6 at C7 / 9). Two pts with PD have not met iwCLL tx criteria and remain in TFO. Five pts have died (suicide, West Nile encephalitis, COVID-19, complications of glioblastoma and RT DLBCL). Five C12 dMRD5 pts who continued ven have reached C18, with only 1 of 5 converting to uMRD5 in PB. However, all 5 maintained uMRD4 (<10-4). Of 3 pts that completed 24C ven (2 ongoing tx), 1 pt had deepening of response to uMRD5 at C24, and 2 pts had rising MRD on ven (dMRD4 at C24). To investigate patient heterogeneity at baseline and its relationship to uMRD, we clustered patient RNAseq samples into two clusters using artificial intelligence/ML based unsupervised clustering. The clusters associated with uMRD6 at C7 (Fisher exact test p=0.038), and patients in the cluster with significantly higher immunosuppressive cells such as T-regulatory cells and M2 macrophages were less likely to be uMRD6 at C7. Conclusions At a median follow-up of 35 months, the estimated 36-month PFS rate is 90%. RNAseq transcriptomic analyses identified that patients with enriched immunosuppressive cells were less likely to be uMRD6 at C7. Additional follow-up is required to confirm the durability of this MRD-guided ven + obin tx strategy.

6538 Background: TP53 mutated ( TP53 mt ) high-risk myeloid neoplasm (HR-MN) confers a dismal prognosis in the contemporary era with only a subset of eligible patients (pts) able to achieve long-term remission with allogeneic stem cell transplantation (allo-HCT). Owing to poor outcomes, many physicians believe it is futile to treat older pts with disease-directed therapy, since curative intent allo-HCT cannot be offered. We sought to describe the outcomes of older pts with TP53 mt HR-MN receiving disease directed treatment. Methods: We conducted a multicenter observational study in collaboration with 11 U.S. academic centers under the COMMAND consortium. We reviewed the data of 451 older (≥ 60 years [yrs]) TP53 mt HR-MN (n= 282 acute myeloid leukemia [AML], n= 91 MDS transformed AML, n= 50 myeloproliferative neoplasm blast phase (MPN-BP) and n= 28 high-risk myelodysplastic syndromes [HR-MDS]) pts to analyze their outcome with disease directed treatment. Results: The median age was 70 yrs (range [R],60-90) and 58% were male. Proportions of pts with age ≥ 70 yrs were 47.5%. Eastern Cooperative Oncology Group Performance Status (ECOG-PS) was available in 68% (n= 306) of pts; 10.5%, 49%, 32% and 8.5% had ECOG-PS 0-3, respectively. The median bone marrow (BM) blast % was 32 (R, 5-99) and TP53 variant allele frequency (VAF) was 45% (R, 2-97). The proportion of pts with multi-hit (MH) TP53 mt and complex cytogenetics (CG) was 83% and 82%, respectively. 43 %, 31%, 20% and 6% received hypomethylating agent (HMA) + venetoclax, intensive chemotherapy, HMA and other low-intensity therapy, respectively. The complete remission rate with or without count recovery (CR/CRi) amongst evaluable patients (n= 356) was 37%. The median duration of response was 6.7 months (mo) (R, 5.9-7.5). Amongst 56 (12%) pts who underwent allo-HCT, the median overall survival (mOS) from time of allo-HCT was 21.9 mo. The mOS among pts ≥ 70 yrs was 6.5 mo. The mOS in mo was better in HR-MDS (16.4), compared to de novo AML (6.5), MDS transformed AML (7.1) and MPN-BP (5.27), p= 0.003. We conducted multivariable analysis for OS using baseline variables that were significant/ showed trend towards significance, on univariate analysis ( p <0.1). HR-MDS (HR; 0.43, 95% CI: 0.23-0.82, p= 0.01), CR/CRi (HR; 0.55, 95% CI: 0.39-0.77, p= <0.001) and allo-HCT (HR; 0.28, 95% CI: 0.16-0.47, p= <0.001) positively impacted OS. Whereas age ≥ 70 yrs showed trends towards inferior OS (HR; 1.31, 95% CI: 0.95-1.80, p=0.09). Complex CG (HR; 1.63, 95% CI: 0.83-3.21, p =0.15) and MH TP53 mut (HR; 1.30, 95% CI: 0.67-2.52, p= 0.42) did not retain significance for OS. Conclusions: Our multi-center study suggests that disease directed treatment in older TP53 mt HR-MN leads to modest response rates with short durations of response in the absence of allo-HCT. 12% of pts were able to receive allo-HCT with improvement in OS close to 2 yrs. The decision to treat this poor risk gp of pts should be based on individual pt characteristics and desires.

Background Acute myeloid leukemia (AML) with TP53 mutation (m) has poor outcomes even in the contemporary era with median overall survival (OS) of 6-9 months. The only factor that has been shown to improve outcomes is allogeneic hematopoietic cell transplantation (allo-HCT) (Badar et al AJH 2022; Leukemia 2023). However, the role of allo-HCT for TP53-m AML continues to be a matter of debate given high rates of relapse after allo-HCT particularly in TP53-m AML with complex cytogenetics (CG). We used the COMMAND consortium database to investigate the factors that influenced physician's decision for allo-HCT in TP53-m AML. Method We conducted a multicenter observational study in collaboration with 7 U.S. academic centers under COMMAND consortium. We reviewed electronic medical records of 369 TP53-m AML patients to analyze reasons for not pursuing allo-HCT including refractory disease, donor availability, advanced age/co-morbidities, physician perspective on ineffectiveness of allo-HCT in improving outcome and patient's decision. Diagnostic criteria for TP53 allelic state were according to the International Consensus Classification (ICC) (Blood 2022; 140:1200). Next-generation sequencing and cytogenetic studies were performed according to institutional standard protocols. Results The median age at diagnosis was 68 years, with 222 (60.5%) patients being male. The majority of patients were diagnosed with de novo AML 179 (48.8%), followed by secondary AML (sAML) in 103 (28%) patients, and therapy-related (t)AML in 85 (23.2%) patients. Ninety-four percent of evaluable patients had complex cytogenetics (CG) and 192 (52%) had multi-hit TP53-m. One-hundred forty-seven (42%) patients received intensive chemotherapy (CPX 351 [66 (44%)], 7+3 [78 (53%)]), while 205 (58%) patients received low-intensity regimens including hypomethylating agents (HMA) plus venetoclax (137 [66%]) and HMA +/- investigational agents (68 [33%]). The rate of complete remission (CR)/CR with incomplete count recovery (CRi) was 34.4% and overall response rate (CR/CRi + partial remission [PR] + morphologic leukemia free state [MLFS]) was 52%. Forty-seven (13%) patients received allo-HCT in CR1 and 17 (5%) patients received allo-HCT in CR2. Of the 294 patients for whom data on allo-HCT decision-making was available, the most common reason for not proceeding to allo-HCT was refractory disease in 126 (43%) patients. Other significant reasons included advanced age/comorbidities (n=78 [30.6%]), physician recommendation (n=7 [2%]), patient's decision (n=24 [9.4%]), and patient relocation or changing healthcare providers (n= 9 [3.5%]). Two (0.4%) patients had no suitable donor available for allo-HCT. Amongst the 7 patients for whom allo-HCT was not pursued due to physician's decision, the median age of the patients was 69 years (R, 59-70), 3 (25%) patients had sAML, and all of them had multi-hit TP53-m associated with complex CG. Six out of seven (86%) patients received HMA plus venetoclax and 1 (14%) patient received HMA-based induction. Six patients achieved CR/CRi after induction and 1 patient had partial remission. The median survival of these patients was 11 months (R, 10.7-11.3), eventually all patients died from progressive AML. Conclusion Our survey suggests that the primary reason for not proceeding with allo-HCT was refractory disease, underlying the difficulty in achieving the disease control needed for allo-HCT. There is an urgent need for better frontline therapies tailored specifically for TP53-m AML, along with refined patient selection criteria to better identify candidates who would benefit most from allo-HCT to potentially improve their long-term outcomes.

Background TP53-mutated (m) acute myeloid leukemia (AML) is an adverse risk disease, which continues to have dismal outcome in the contemporary era of novel therapies. Venetoclax (VEN) in combination with hypomethylating agents (HMA; azacitidine or decitabine) have shown to improve complete remission (CR) rates compared to HMA alone, however no significant differences in overall survival (OS) have been observed. Methods We conducted a retrospective study through the COMMAND consortium (a collaboration of acute leukemia experts from 10 US academic institutions) to analyze the impact on survival outcomes of HMA plus (+) VEN compared to HMA-based therapies in adult (≥18 years) pts with TP53m AML. The AML Database of 381 pts with TP53m AML diagnosed between 2012-2022 was queried and 154 (40%) (HMA [n=50] and HMA +VEN [n=104]) pts were identified eligible for this analysis. Continuous variables were summarized as median (range) while categorical variables were reported as frequency (percentage). The Kaplan-Meier method was used to estimate OS, defined as time from diagnosis to death or last follow-up. Logistic regression models were used to determine the univariate and multivariate of OS. Multivariable models included all significant univariate predictors. All tests were two-sided with a p value &lt;0.05 considered statistically significant. Results Baseline characteristics and responses The median age (years [yrs]) was 74 (range [R], 38-87) and 71 (R,29-88) yrs in the HMAand HMA + VEN groups (gps) (p= 0.23), respectively ( Table 1). Thirty-four (68%) and 57 (55%) patients (pts) were ≥ 70 yrs in the HMA and HMA + VEN gps, respectively (p= 0.16). Twenty-six percent vs 31% ( p=0.57), 86% vs 90% ( p=0.58) and 68% vs 73% ( p=0.56) of pts had secondary AML, had complex cytogenetics (CG), and had multi-hit TP53m in the HMA and HMA + VEN gps, respectively. The proportion of pts with most frequently occurring (&gt; 5%) myeloid co-mutations ( RUNX1, ASXL1, TET2, DNMT3A, RAS, PTPN11 and JAK2) were not significantly (NS) different between the HMA and HMA + VEN gps, as shown in Table 1. The early treatment related mortality in first 30 days of induction was higher in the HMA+VEN gp (25%) when compared with the HMA gp (6%), p=0.004. The complete remission rates (CR/CRi) were higher in the HMA + VEN gp compared to the HMA gp (35% vs 18%, p=0.05). Similarly, the proportion of pts receiving allogeneic stem cell transplant (allo-HCT) after induction was higher in the HMA + VEN gp when compared with the HMA gp (13% vs 4%; p=0.14). Duration of response and overall survival The median follow up was 9.8 months (mo) (R, 1-56) and 5.80 mo (R, 1-30.4) in the HMA and HMA + VEN gps, respectively ( p=0.12). The median duration of response (DOR) was higher in the HMA +VEN gp (15.6 mo) when compared with the HMA gp (7.93 mo), but NS ( p=0.26). The median OS was NS different when comparing the HMA and HMA + VEN gps (9.23 vs 7.3 mo, p=0.80 [ Figure 1]). Multivariable analysis for duration of response and overall survival We did multivariable analysis (MVA) for DOR and OS using baseline variables ( Table 1) that showed significance/trend towards significance in univariate analysis ( p&lt;0.1). Allo-HCT (HR; 0.11, 95% CI: 0.02-0.52, p=0.005) retained significance for better DOR, whereas age ≥ 70 yrs (HR; 1.7, 95% CI: 0.63-4.65, p=0.28) and complex CG (HR; 3.05, 95% CI: 0.79-11.73, p=0.10) did not retain significance in MVA. In MVA for OS, achievement of CR/CRi (HR; 0.35, 95% CI; 0.20-0.59, p=&lt;0.001) and allo-HCT after induction (HR; 0.06, 95% CI; 0.09-0.46, p=0.007) retained favorable significance for OS, whereas complex CG (HR; 2.36, 95% CI: 1.11-4.99, p=0.02) retained significance for shorter OS. PTPN11m (HR; 1.57, 95%CI: 0.75-3.28, p=0.23) and TET2m (HR; 1.02, 95% CI: 0.56-1.87, p= 0.92) did not retain significance in MVA. Conclusion In this multi-center real-world study, while HMA+VEN led to improvement in CR rates and a higher proportion of pts were bridged to allo-HCT, it did not associate with an improvement in OS when compared with HMA monotherapy. More effective treatment strategies are warranted to improve outcome of pts with TP53m AML.

INTRODUCTION: Luxeptinib (CG-806; LUX) is an orally active noncovalent kinase inhibitor of Bruton's tyrosine kinase (BTK), wild type and mutant forms of Fms-like tyrosine kinase 3 (FLT3) (including the internal tandem duplicates (ITD), tyrosine kinase domain (TKD), and F691L mutant forms), and growth receptors like KIT, CSF1R, PDGFRα, and TRKs. In prior studies, LUX has been shown to suppress aberrant proliferative signaling in B cell malignancies and acute myeloid leukemia (AML) via regulation of BTK, LYN, SYK, AKT, ERK, and MAPK. LUX is cytotoxic to primary AML cells insensitive to other FLT3 inhibitors and to malignant B-cells insensitive to ibrutinib, at pM and nM concentrations, respectively. AIMS: The primary objectives of these studies are to assess the safety, tolerability, and pharmacokinetics (PK) of LUX and determine recommended phase 2 doses for relapsed or refractory (R/R) AML and B cell malignancy patients. METHODS: In two studies (NCT04477291; NCT03893682), LUX (original formulation, G1) was administered continuously as oral capsules BID in 28-day cycles of ascending cohorts (relapsed or refractory de novo, secondary, or therapy-related AML or higher risk myelodysplastic syndrome (MDS), and relapsed and refractory for B cell lymphoma and chronic lymphocytic/small lymphocytic leukemia). A novel generation 3 (G3) formulation of LUX designed to increase bioavailability was tested at a single-dose (sub-study) for relative bioavailability (RBA), followed by continuous dosing in subsequent R/R AML patients. RESULTS: In the B-cell study (as of 15 th May 2023), LUX has been administered to 36 patients at dose levels from 150 mg to 900 mg BID in patients with a median of 3 lines of prior treatment, with 47.2% having received a BTK-inhibitor. Only one (2.8%) patient had a DLT of hypertension and 14 (38.9%) experienced at least one drug related ≥Grade3 treatment emergent adverse event (TEAE). Two patients (900 mg) are currently on study with no DLT and no ≥Grade 3 related TEAEs. A Follicular lymphoma patient is at cycle 28, and achieved a best response as partial response (PR) with a decrease in lesion size of 76.2%; an SLL patient is at cycle 13, and achieved stable disease (SD) showing a decrease in lesion size of 43.1% (Figure A). The overall best response achieved among the 17 patients who have been on treatment for more than 12 weeks are stable disease (SD) (n=11), partial response (PR) (n=3), minor response (n=2) and complete response (CR) (n=1). As of 5 th June 2023, in the AML trial, a total of 40 patients (16 (40%) FLT3-ITD, 21 (52.5%) FLT3-WT, 2 (5.0%) FLT3-TKD, and 1 (2.5%) unknown mutations) with a median of 3 prior treatments (range, 1 - 10) have been treated with LUX G1 formulation at dose levels from 450 mg - 900 mg BID (n=34) or with 50 mg BID of G3 formulation (n=6). Four (10%) experienced drug related SAE and 7 (17.5%) had a drug related grade ≥3 TEAEs. The most common related TEAEs were lymphocyte count decrease, platelet count decrease, and anemia (n=2; 5% patients each). One (2.5%) patient at 450 mg dose, reported complete remission without minimum residual disease (CRmrd) and remained on study for 56 weeks. In the RBA sub-study, G3 (50 mg) produced comparable exposures to G1 (450-900 mg range) (Figure B) and was, therefore, selected as the starting dose for use in the R/R AML study. Six patients were treated with a continuous dosing of 50 mg BID G3; with plasma levels of 274 ng/mL and 195 ng/mL LUX observed by the end of C1D15 and C1D22 respectively. No drug related Grade ≥3 TEAEs or DLTs were observed in 50 mg BID G3 LUX treated patients; with no new safety signals observed for the G3 formulation. Based on these findings and expected exposures for higher dose levels, the cohort safety review committee has approved escalation of G3 dosing to 200 mg BID at which dosing is ongoing. CONCLUSIONS: LUX has a favorable safety profile in patients at all tested dose levels, for multiple cycles, for both studies. Antitumor activity was observed in a heavily pretreated relapsed AML patient and in multiple B-NHL subtypes and CLL/SLL patients including several with prior ibrutinib exposure. Continuous dosing of patients with R/R AML and Higher-Risk MDS with the G3 formulation is ongoing; with updated clinical data (200 mg dose level) to be presented at the meeting.

AbstractBackgroundAlthough the clinical outcomes of patients with TP53‐mutated acute myeloid leukemia (AML) are dismal, subsets of patients eligible for curative‐intent therapies may fare better. Because racial disparities are known to affect outcome in hematologic malignancies, the authors sought to explore disparities among patients with TP53‐mutated AML.MethodsA multicenter, retrospective study was conducted in a cohort of 340 patients who had TP53‐mutated AML (275 non‐Hispanic White [NHW] and 65 non‐Hispanic Black [NHB]) to analyze differences in treatment and outcome among NHW and NHB patients.ResultsThe median patient age was comparable between NHW and NHB patients (p = .76). A higher proportion of NHB patients had therapy‐related AML (31% vs. 20%; p = .08) and had co‐mutations (74% vs. 61%; p = .06). A higher proportion of NHW patients received intensive chemotherapy compared with NHB patients (47% vs. 31%; p = .02). Conversely, a higher proportion of NHB patients received low‐intensity chemotherapy (9% vs. 5.5%; p = .02) or best supportive care (22% vs. 7%; p < .001). The complete response rate (including complete responses with or without complete count recovery) was 31% versus 24.5% (p = .39) in NHW and NHB patients, respectively. Only 5% of NHB patients received allogeneic stem cell transplantation compared with 15.5% of NHW patients (p = .02). The proportion of patients who were event‐free (18.5% vs. 8.5%; p = .49) or who remained alive (24.9% vs. 8.3%; p = .13) at 18 months was numerically higher in NHW versus NHB patients, respectively, but was not statistically significant.ConclusionsThe current study highlights disparities between NHW and NHB patients with TP53‐mutated AML. Efforts are warranted to eliminate treatment disparities in minority populations.

Abstract We conducted a multi-center study to analyze factors predicting survival among patients with TP53-mutated (m) AML receiving allogeneic hematopoietic stem cell transplant (allo-HSCT) in the recent era. Among 370 patients, 68 (18%) patients were bridge to allo-HSCT. The median age of the patients was 63 years (range, 33–75), 82% of patients had complex cytogenetics and 66% of patients had multi-hit TP53m. Forty three percent received myeloablative conditioning (MAC) and 57% received reduced intensity conditioning (RIC). The incidence of acute graft versus host disease (GVHD) was 37% and chronic GVHD was 44%. The median event-free survival (EFS) from the time of allo-HSCT was 12.4 months (95% CI: 6.24–18.55) and median overall survival (OS) was 24.5 months (95% CI: 21.80-27.25). In multivariate analysis utilizing variables that showed significance in univariate analysis, complete remission at day 100 post allo-HSCT retained significance for EFS (HR: 0.24, 95% CI: 0.10–0.57, p = 0.001) and OS (HR: 0.22, 95% CI: 0.10–0.50, p = < 0.001). Similarly, occurrence of chronic GVHD retained significance for EFS (HR: 0.21, 95% CI: 0.09–0.46, p = < 0.001) and OS (HR: 0.34, 95% CI: 0.15–0.75, p = 0.007). Our report suggests that allo-HSCT offers the best opportunity to improve long-term outcome among patients with TP53m AML.