Red Blood Cell Transfusion Independence Research Articles

A phase 3b study of venetoclax and azacitidine or decitabine in an outpatient setting in patients with acute myeloid leukemia.

Venetoclax, a highly selective BCL-2 inhibitor, combined with hypomethylating agents (HMAs) azacitidine or decitabine, is approved for the treatment of newly diagnosed acute myeloid leukemia (ND AML) in patients who are ineligible to receive intensive chemotherapy. Previous clinical studies initiated venetoclax plus HMA in an inpatient setting owing to concerns of tumor lysis syndrome (TLS). This study (NCT03941964) evaluated the efficacy and safety of venetoclax plus HMA in a United States community-based outpatient setting in patients with ND AML (N=60) who were treatment naïve for AML, ineligible to receive intensive chemotherapy, had no evidence of spontaneous TLS at screening, and were deemed as appropriate candidates for outpatient initiation of venetoclax plus HMA by the investigator. Patients received venetoclax in combination with azacitidine (75mg/m2) or decitabine (20mg/m2) for up to 6 cycles during the study. With a median time on study of 18.3weeks, the best response rate of composite complete remission was 66.7%, and the overall post-baseline red blood cell (RBC) and platelet transfusion independence rate was 55.0%, consistent with results of studies in which treatment was initiated in an inpatient setting. Key adverse events included nausea, anemia, thrombocytopenia, neutropenia, and white blood cell count decrease of any grade (≥50% of patients). The observed safety profile was generally consistent with that of venetoclax plus HMA observed in inpatient AML studies. With close monitoring, 2 cases of TLS were identified, appropriately managed, and the patients were able to continue study treatment. CLINICAL TRIALS REGISTRATION: This study is registered at ClinicalTrials.gov. The registration identification number is NCT03941964.

Lack of RBC transfusion independence by Day 30 following allogeneic hematopoietic stem cell transplant strongly predicts inferior survival and high non-relapse mortality in acute myeloid leukemia patients.

Studies have suggested that acute myeloid leukemia (AML) patients with incomplete hematologic recovery undergoing allogeneic stem cell transplantation (allo-HSCT) had inferior overall survival (OS). This single-center, retrospective study of AML patients evaluated the relationship between red blood cell (RBC) and platelet (PLT) transfusion requirements during the first 30 days and long-term outcomes after allo-HSCT through multivariate analyses. A total of 692 AML patients received peripheral blood stem cells (89.2%), marrow (5.6%), or umbilical cord (5.2%) from matched related (37.4%), unrelated (49.1%), or haploidentical (8.2%) donors in 2011-2017. Transfusion requirements during the first 30 days for RBC (89.5% transfused, median 3, range 1-18 units) or PLT (98.2% transfused, median 6, range 1-144 units) were variable. By Day 30, 56.7% (95% confidence interval [CI]: 52.8-60.3%) and 86.1% (95% CI: 83.2-88.5%) had achieved RBC and PLT transfusion independence, respectively. Median follow-up among survivors (n = 307) was 7.1 years (range: 2.7-11.8). Lack of RBC transfusion independence by Day 30 was strongly and independently associated with worse 5-year OS (39.2% vs. 59.6%, adjusted hazard ratio [HR] 1.83, 95% CI: 1.49-2.25), leukemia-free survival (35.8% vs. 55.5%, HR = 1.75, 95% CI: 1.43-2.14), and NRM (29.7% vs. 13.7%, HR = 2.05, 95% CI: 1.45-2.89) (p < .001). There was no difference in relapse rates among patients who achieved or did not achieve RBC (p = .34) or PLT (p = .64) transfusion independence. Prolonged RBC dependence predicted worse survival and NRM rates, but not increased relapse. Posttransplant surveillance of such patients should be adjusted with more attention to non-relapse complications.

Imetelstat in patients with lower-risk myelodysplastic syndromes who have relapsed or are refractory to erythropoiesis-stimulating agents (IMerge): a multinational, randomised, double-blind, placebo-controlled, phase 3 trial

Unmet medical needs remain in patients with red blood cell transfusion-dependent (RBC-TD) lower-risk myelodysplastic syndromes (LR-MDS) who are not responding to or are ineligible for erythropoiesis-stimulating agents (ESAs). Imetelstat, a competitive telomerase inhibitor, showed promising results in a phase 2 trial. We aimed to compare the RBC transfusion independence (RBC-TI) rate with imetelstat versus placebo in patients with RBC-TD LR-MDS. In phase 3 of IMerge, a double-blind, placebo-controlled trial conducted in 118 sites including university hospitals, cancer centres, and outpatient clinics in 17 countries, patients (aged ≥18 years) with ESA-relapsed, ESA-refractory, or ESA-ineligible LR-MDS (low or intermediate-1 risk disease as per International Prognostic Scoring System [IPSS] criteria) were randomly assigned via a computer-generated schedule (2:1) to receive imetelstat 7·5 mg/kg or placebo, administered as a 2-h intravenous infusion, every 4 weeks until disease progression, unacceptable toxic effects, or withdrawal of consent. Randomisation was stratified by previous RBC transfusion burden and IPSS risk group. Patients, investigators, and those analysing the data were masked to group assignment. The primary endpoint was 8-week RBC-TI, defined as the proportion of patients without RBC transfusions for at least 8 consecutive weeks starting on the day of randomisation until subsequent anti-cancer therapy, if any. Primary efficacy analyses were performed in the intention-to-treat population, and safety analyses were conducted in patients who received at least one dose of trial medication or placebo. This trial is registered with ClinicalTrials.gov (NCT02598661; substudy active and recruiting). Between Sept 11, 2019, and Oct 13, 2021, 178 patients were enrolled and randomly assigned (118 to imetelstat and 60 to placebo). 111 (62%) were male and 67 (38%) were female. 91 (77%) of 118 patients had discontinued treatment by data cutoff in the imetelstat group versus 45 (75%) in the placebo group; a further one patient in the placebo group did not receive treatment. Median follow-up was 19·5 months (IQR 12·0-23·4) in the imetelstat group and 17·5 months (12·1-22·7) in the placebo group. In the imetelstat group, 47 (40% [95% CI 30·9-49·3]) patients had an RBC-TI of at least 8 weeks versus nine (15% [7·1-26·6]) in the placebo group (rate difference 25% [9·9 to 36·9]; p=0·0008). Overall, 107 (91%) of 118 patients receiving imetelstat and 28 (47%) of 59 patients receiving placebo had grade 3-4 treatment-emergent adverse events. The most common treatment-emergent grade 3-4 adverse events in patients taking imetelstat were neutropenia (80 [68%] patients who received imetelstat vs two [3%] who received placebo) and thrombocytopenia (73 [62%] vs five [8%]). No treatment-related deaths were reported. Imetelstat offers a novel mechanism of action with durable transfusion independence (approximately 1 year) and disease-modifying activity for heavily transfused patients with LR-MDS who are not responding to or are ineligible for ESAs. Janssen Research & Development before April 18, 2019, and Geron Corporation thereafter.

Efficacy of Imetelstat in Achieving Red Blood Cell Transfusion Independence (RBC-TI) across Different Risk Subgroups in Patients with Lower-Risk Myelodysplastic Syndromes (LR-MDS) Relapsed/Refractory (R/R) to Erythropoiesis-Stimulating Agents (ESAs) in IMerge Phase 3 Study

CONCLUSIONS IMerge (NCT02598661) is a phase 2/3 global study of imetelstat, a first-in-class telomerase inhibitor, for patients with RBC transfusion-dependent non-del(5q) LR-MDS R/R to or ineligible for ESAs, a population with unmet needs. Phase 3 results showed that the rate of ≥8-week, ≥24-week and 1-year RBC-TI was higher with imetelstat than placebo (Zeidan et al. ASCO 2023. Abstr 7004; Platzbecker et al. EHA 2023. Abstr S165). Toevaluate clinical efficacy of imetelstat across different International Prognostic Scoring System (IPSS), revised IPSS (IPSS-R), IPSS-R cytogenetic, or IPSS-molecular (IPSS-M) risk categories,cytogenetic analysis was performed centrally on bone marrow aspirates by karyotyping, and mutation profile was analyzed using peripheral blood samples by next-generation sequencing on a panel of 36 genes commonly mutated in MDS. Baseline IPSS, IPSS-R, IPSS-R cytogenetic, or IPSS-M risk categories were derived for patients in the phase 3 portion of IMerge based on specific classification criteria, and rates of RBC-TI ≥8-week, ≥24-week, ≥1-year were assessed for each risk subgroup. In 105 IPSS-low patients, 95 (90.5%) remained IPSS-M very low/low/moderate low, and 10 patients (9.5%) upstaged to IPSS-M moderate high and high. In 50 IPSS-intermediate-1 patients, 39 (78%) remained IPSS-M very low/low/moderate low, and 11 patients (22%) upstaged to IPSS-M moderate high/high. Among 129 IPSS-R low/very low patients, 118 (91.5%) remained IPSS-M very low/low/moderate low, and 11 (8.5%) patients upstaged to IPSS-moderate high/high. In 25 IPSS-R-intermediate patients, 16 (64%) remained IPSS-M low/moderate low, and 9 patients (36%) upstaged to IPSS-M moderate high/high/very high. One IPSS-R high-risk patient remained IPSS-M high. Overall, significantly higher rates of ≥8-week, ≥24-week, and ≥1-year RBC-TI were achieved in patients receiving imetelstat (39.8%, 28%, and 13.6%) vs those receiving placebo (15%, 3.3%, and 1.7%). Further subgroup analysis demonstrated that imetelstat consistently had higher TI response rates than placebo across different risk subgroups, irrespective of classification system. For IPSS risk groups, the TI rates of ≥8-week, ≥24-week, and ≥1-year with imetelstat vs placebo were 40.0% vs 20.5% ( P = 0.034), 28.8% vs 5.1% ( P = 0.003), and 12.5% vs 2.6% ( P = 0.082), respectively, in patients with low risk and 39.5% vs 4.8% ( P = 0.004), 26.3% vs 0% ( P = 0.009), and 15.8% vs 0% ( P = 0.048), respectively, in patients with intermediate-1 risk. For IPSS-R risk groups, the TI rates of ≥8-week, ≥24-week, and ≥1-year with imetelstat vs placebo were 42.5% vs 19.6%, 29.9% vs 4.3%, and 11.5% vs 2.2%, respectively, in the low-risk subgroup. The TI rates of ≥8-week, ≥24-week, ≥1-year TI with imetelstat were 35%, 25%, and 20%, respectively, in the intermediate-risk subgroup, whereas placebo treatment had no response. The number of patients was too low in both arms of the very low or high IPSS-R subgroups to assess difference in TI response. For IPSS-R cytogenetic risk groups, the TI rates of ≥8-week, ≥24-week, and ≥1-year with imetelstat vs placebo were 37.1% vs 17.0%, 24.7% vs 4.3%, and 10.1% vs 2.1%, respectively, in very good/good risk groups and 54.5% vs 11.1%, 40.9% vs 0%, and 22.7% vs 0%, respectively, in the intermediate-risk group. For IPSS-M risk groups, the TI rates of ≥8-week, ≥24-week, and ≥1-year with imetelstat vs placebo were 47.8% vs 21.2%, 34.8% vs 3%, and 14.5% vs 0%, respectively, in patients with very low/low risk and 20.7% vs 6.3%, 10.3% vs 0%, and 6.9% vs 0%, respectively, in patients with moderate low/moderate high risk. In patients with high/very high risk, ≥8-week TI rates were 40% vs 0% with imetelstat vs placebo, with no ≥24-week or ≥1-year TI observed in either arm. All results are summarized in the Table. Improvement in RBC-TI rates was observed in patients treated with imetelstat vs placebo across different risk subgroups as defined by IPSS, IPSS-R, IPSS-R cytogenetic, or IPSS-M risk profiles. Notably, placebo had not achieved durable (≥24-week and ≥1-year) TI response in the higher-risk groups irrespective of the risk classification assessment model used, while TI response rates with imetelstat in higher-risk subgroups with poor prognosis were similar to TI response rates in lower-risk subgroups of heavily transfused R/R ESA LR-MDS, indicating that clinical efficacy of imetelstat is independent of risk categories.

Phase 1b Trial of Irak 1/4 Inhibition for Low-Risk Myelodysplastic Syndrome Refractory/Resistant to Prior Therapies: A Trial in Progress

Background and Significance: Chronic stimulation of both the interleukin-1 receptor (IL-1R) and toll-like receptors (TLRs) in myeloid progenitors is thought to promote a proinflammatory environment in the bone marrow that causes persistent cytopenia in patients with low-risk myelodysplastic syndrome (LR-MDS). The serine/threonine kinases IRAK1 and IRAK4 are critical for the signaling downstream of IL-1R and most TLRs that promotes production of proinflammatory cytokines and NLRP3 inflammasome-driven pyroptosis, leading to bone marrow inflammation and cell death. Therefore, inhibition of IRAK1/4 is a potential target for the treatment of LR-MDS by decreasing inflammation and cell death within the bone marrow, allowing for restoration of hematopoiesis. R289 is a prodrug that is converted to the active drug R835 in the gastrointestinal (GI) tract. R835 is a potent and selective inhibitor of IRAK1 and IRAK4 kinases that inhibits TLR and IL-1R-dependent proinflammatory cytokine production in multiple cell types. In vivo, R835 blocks TLR4 and IL-1R-dependent systemic cytokine release in mice. The safety and pharmacokinetic properties of R289/R835 were evaluated in a phase 1 study in healthy volunteers (Study C-906289-001). R289 was well tolerated with no serious or severe adverse events (AEs) reported. Most AEs were mild and transient; the most common AEs (mild/moderate) were headache and GI disturbance. Overall, the phase 1 trial results supported the further study of R289. An open-label phase 1b study to determine the tolerability and preliminary efficacy of R289 for patients with LR-MDS refractory to prior therapies is currently recruiting patients. Study Design and Methods: The R289 phase 1b study (NCT05308264) is an open label, single arm, multi-center study, which includes a dose escalation phase (up to 12 patients) and a dose expansion phase (up to 10 patients). Inclusion criteria for both phases will include patients ≥18 years with a definitive diagnosis of low-risk MDS (International Prognostic Scoring System-R ≤3.5) and ≤5% bone marrow myeloblasts. Patients must be relapsed or refractory/resistant or intolerant to prior MDS therapies. Exclusion criteria include prior MDS treatment(s) within 4 weeks of study treatment, clinically significant anemia (from iron deficiency, hemolysis, or GI bleeding), and chronic myelomonocytic leukemia. Dose Escalation Phase: A 3+3 dose escalation design will be used to determine the maximum tolerated dose (MTD). An initial R289 dose of 250 mg qd, will be given orally, with or without food, progressing to 500 mg qd with dose limiting toxicity (DLT) assessed at both doses. The DLT evaluation period will be 28 days. After completion, patients not experiencing DLTs may remain at their respective dose levels as long as they demonstrate continued clinical benefit without toxicity. Dose Expansion Phase: Up to 10 additional patients with LR-MDS will be enrolled, with R289 administered to all patients at a dose not exceeding the MTD determined in the dose escalation phase. The primary endpoint of the study is safety and tolerability of R289, assessed by incidence of AEs, discontinuation/interruption of R289 due to AEs, and incidence of DLTs. Secondary endpoints include preliminary efficacy, assessed by red blood cell transfusion independence by Week 24 (% achieving ≥50% reduction in transfusions), and pharmacokinetics of R289. Change from baseline in plasma biomarkers, including C-reactive protein and TNFα, and bone marrow biomarkers will be assessed. Statistical analyses will be primarily descriptive. Tabulations will be produced for disposition, demographics, disease characteristics, safety, pharmacokinetics, pharmacodynamics, and clinical activity. For analyses of clinical activity, such as proportion of patients with RBC transfusion independence, complete responder rate, overall response rate, and proportion of subjects with hematologic improvements, the summary will be produced separately for the dose escalation phase and dose expansion phase. For the dose escalation phase, data will be summarized by dose level and overall. The trial is currently recruiting at 9 US sites. The study has enrolled 7 patients in the dose escalation phase.

Safety and Efficacy Results from CLI120-001 a Phase 1 Study in RR-AML and HR-MDS: Update from Higher Dose Levels

Background: RVU120, a first-in-class CDK8/19 kinase inhibitor, showed antileukemic activity mediated by inhibition of STAT5 phosphorylation in AML cell lines and patient-derived cells.Clinical activity in a population of patients with relapsed/refractory AML and HR-MDS with poor prognostic factors was shown in a currently ongoing phase 1 dose escalation study (NCT04021368) consistent with the preclinical evidence of both cytotoxic and erythroid and myeloid differentiation effects in cell and mouse models. Aims: The primary objective of the study is to determine the safety profile and the recommended phase 2 dose (RP2D) of RVU120 as a single agent in R/R AML and HR-MDS. Secondary objectives include the characterization of PK, antitumor activity, and exploratory pharmacodynamic (PD) effects. Methods: CLI120-001 is an open-label, multi-center, dose escalation study. RVU120 is administered orally every other day, for a total of 7 doses, in a 3-week treatment cycle until disease progression or unacceptable toxicity. Adverse events are graded according to NCI-CTCAE v.5.0. DLTs are assessed at the completion of Cycle 1. Disease evaluation is performed according to Dohner 2017 and Cheson 2006 response criteria for AML and MDS respectively. Pharmacodynamic assessments (PD) include a flow cytometry assay to assess target engagement by evaluating changes in phosphorylated STAT5. Results: As of 26 Jul 2023, 31 patients received RVU120 at doses between 10 and 175 mg, median age 71 years, median of 3 prior lines of therapy. ECOG PS was 2 in 8 pts, 1 in 20 pts, and 0 in 3pts. No severe drug reactions, no DLT have been reported, with manageable nausea and vomiting being the most frequent treatment-emergent adverse events. Twelve out of the 24 evaluable patients showed clinically relevant benefit. Four patients achieved a reduction of blasts to &amp;lt;5% in the BM: One patient with NPM1 and FLT3 mutated AML, achieved a CR, 3 patients with HR-MDS had a marrow CR, one of those had G3 BM fibrosis and is currently in C3 of treatment. 3 additional patients treated across different dose levels experienced a sustained BM blast reduction: 2 patients with TP53+ AML with 37% and 74% BM blast reduction, 1 patient with AML-MRC and monosomy 7 with 28% blast reduction; 1 patient with AML-MRC failing 4 lines of therapy received allogeneic BM transplantation after 6 cycles of RVU120 treatment. 5 patients achieved hematology improvement including: 1 patient with HR-MDS failing 2 lines of therapy, 1 patient with AML secondary to MF, became RBC transfusion independent (TI) and is still ongoing after &amp;gt;18 months with nearly normal Hgb and Plts values. 2 patients with AML-MRC, with baseline RBC and Plt transfusion dependance (TD), became TI and reached normal Plts values. 1 patient with AML-MRC with RBC and Plt TD and severe neutropenia showed RBC and Plt TI and ANC recovery and is currently in C7 of treatment. A correlation between pSTAT5 inhibition and RVU120 exposure was observed. Conclusion: In the ongoing phase 1 trial, RVU120 shows clinical activity in both AML and HR-MDS, inducing RBC transfusion independence and blast reduction with a tolerable safety profile. Clearance of BM blasts including a formal CR were observed in patients treated at different dose levels. Relevant target inhibition is achieved from 110 mg onwards with expected higher pSTAT 5 inhibition with further dose escalation.

Hematological Response to Frontline Treatment in Lower Risk Myelodysplastic Syndromes (LRMDS) Is Associated with Better Overall Survival

Background The majority of LRMDS patients (pts) (70%) do not progress but unfortunately succumb to complications related to cytopenia, namely anemia and red blood cell transfusion dependency (RBC-TD) or their interplay with co-morbidities. RBC-TD is associated with worse outcome reflecting bone marrow failure and long-term sequela of RBC-TD. There is growing evidence that response to treatment and RBC transfusion independence (TI) are associated with favorable outcome. In lieu of 2 recent randomized clinical trials demonstrating efficacy of luspatercept &amp; imetelstat in LRMDS, we assessed the impact of response to sequential lines of treatment in LR-MDS on overall survival (OS) to guide our treatment choices and to determine whether erythroid stimulating agents (ESA) should still be our 1 st line of therapy. Methods We included LRMDS pts (IPSS-R very low &amp; low) from Moffitt Database who received ESA as frontline therapy (FL) and assessed subsequently outcomes with second line (SL) therapy (SOC or clinical trial). We excluded MDS/MPN and del5q pts. We also excluded all pts who eventually progressed to either higher risk MDS or AML to better reflect the majority LRMDS in that disease state. We assessed details of FL and SL. Pts who received FL &amp; SL were then divided into 4 groups based on response to FL and SL therapy: group 1 (no/no), group 2 (no/yes) with response only to SL, group 3 (yes/no) response to FL only, and group 4 (yes/yes) with response to both lines of therapy. Response was defined as hematological improvement (HI) with ≥1.5 g/dl Hgb increase in non-TD pts and RBC-TI in TD pts at baseline for at least for 8 weeks. We compared median OS (mOS) among those groups. Results There were 603 LRMDS pts who met eligibility criteria and received ESA as FL (Table-1); 43% were RBC-TD, mean serum EPO was 132 (n=211 pts), 69% received epoetin, 17% darbepoetin and 14% with G-CSF. HI was observed in 42% of pts with no difference among ring sideroblasts (RS) +/- (46% vs 40%, p =.12). Response was higher among non-RBC-TD (52% vs 31%, p&amp;lt; .001). The median time to start ESA was 1.2 mo (0-249). The median time on ESA therapy was 11 mo (.4-213). 331 pts (55%) received SL which included HMA 43% (n= 142), lenalidomide 39% (n=130), luspatercept 7% (n=24), ATG 2% (n=8), investigational agent 4% (n=14), and other 4% (n=13) . The HI rate was 27% (91/331). No difference in HI based on RS nor RBC-TD was observed. The median duration on SL treatment was 6 mo (.1-93). 170 pts (28%) received 3 rd line of therapy with 7% HI, 88 pts (15%) received 4 th line of therapy with 3% HI and 39 pts (7%) had 5 th line of therapy with 2% HI. Among the 331 pts who received at least FL and SL, pts were divided into 4 groups based on response to (methods, table-2), the mOS was 114 mo among Yes/Yes response group, 103 mo among yes/no group, 97 mo no/yes and 64 mo among no/no ( P=.007; Figure-1). Response to FL was significantly associated with better OS after adjusting for RS (HR .74 ,95% CI .55-.99, p=.043). Conclusions Only half of patients who receive ESA as FL therapy for LRMDS received any subsequent therapies. Response rates were highest with ESA as FL than any SL therapy. HI with FL and/or SL is associated with improved OS. Lack of response to first line of therapy is associated with worse OS. Responses beyond SL were rarely observed. Identifying and moving agents with high HI rate as FL therapy and or selecting option based on predictors of best chance of response to a specific treatment as FL may lead to better overall survival.

Efficacy and Safety of Venetoclax in Combination with Azacitidine for the Treatment of Patients with Treatment-Naive, Higher-Risk Myelodysplastic Syndromes

Introduction: Azacitidine (Aza) has been shown to prolong survival in patients with treatment-naive, higher-risk myelodysplastic syndrome (HR MDS) compared to lower-intensity, conventional treatment regimens; however, improvement in clinical outcomes are needed. Clinical data on the synergy of Aza with venetoclax (Ven)-a selective, potent BCL-2 inhibitor-in the treatment of myeloid malignancies and the unmet need in HR MDS provide a rationale to evaluate Ven in combination with Aza in treatment-naive HR MDS. Here, we report efficacy and safety data in patients with treatment-naive HR MDS treated with Ven+Aza at the recommended Phase 2 dose (RP2D) in the safety expansion part of the Phase 1b study (NCT02942290). Methods: Adult patients were enrolled with de novo treatment-naive HR MDS defined by the Revised International Prognostic Scoring System (IPSS-R) score of &amp;gt;3 with an Eastern Cooperative Oncology Group performance status of ≤2, and bone marrow (BM) blasts &amp;lt;20% at baseline. Patients received Ven 400 mg orally daily on Days 1-14 and Aza 75 mg/m 2 intravenously or subcutaneously on Days 1-7 or on Days 1-5, 8, and 9 of each 28-day cycle (RP2D). The primary objective was to assess the complete remission (CR) rate. Key secondary objectives included determining marrow CR (mCR), overall response rate (ORR), hematologic improvement (HI), postbaseline red blood cell (RBC) and platelet transfusion independence (TI), overall survival (OS), duration of CR, time to next treatment (TTNT), transformation to acute myeloid leukemia (AML), and time to AML transformation. Responses were assessed by International Working Group 2006 criteria. Prophylactic antibiotics were mandated in Cycle 1 and recommended for Grade ≥3 neutropenia thereafter. Safety was analyzed in patients who received ≥1 dose of study treatment. Results: At thedata cutoff of May 31, 2023, 107 patients had received Ven+Aza at the RP2D. Key baseline characteristics for all treated patients are shown in Table 1A. Median age was 68 years (range, 26-87), 64% of patients had intermediate or poor cytogenetic risk, and &amp;gt;89% had ≥5% BM blasts. Median number of treatment cycles before transplantation was 3.0 (range, 1.0-11.0). At the median follow-up of 31.9 months (95% CI, 30.4-42.5), CR rate was 29.9% (95% CI, 21.4-39.5), with a median CR duration of 16.6 months (95% CI, 10.0-not reached [NR], Table 1B). Median OS was 26 months (95% CI, 18.1-51.5), with an estimated 12-month OS of 71.2% (95% CI, 61.4-78.9)and 24-month OS of 51.3% (95% CI, 41.2-60.5). Median OS for CR was NR. Median TTNT including transplantation was 6.8 months (95% CI, 5.6-8.3). Sixty-two (57.9%) patients received subsequent treatment, including transplantation in 42 (39.3%) patients; the median time to transplantation was 4.8 months (range, 1.4-16.8). Among patients who received transplantation post-study, 17 were transplant ineligible at study entry. Postbaseline TI rate was 61.7% for RBC and 72.0% for platelets. Median maximal duration of TI achieved was 5.4 months (range, 1.8-50.8) and 5.4 months (range, 1.9-56.0) for RBC and platelets, respectively. Postbaseline overall hematologic improvement (HI) was achieved in 51 (49.0%) of 104 evaluable patients, and specific responses included erythroid (40/93; 43.0%), platelet (32/74; 43.2%) and neutrophil (10/57; 17.5%) indices. All patients experienced ≥1 treatment-emergent adverse event (TEAE), with 94.4% of patients reporting grade ≥3 TEAEs. Serious adverse events (SAEs) occurred in 68.2% of patients. Common TEAEs of any grade were constipation (53.3%), nausea (49.5%), neutropenia (48.6%), thrombocytopenia (44.9%), febrile neutropenia (42.1%), diarrhea (41.1%), anemia (39.3%), vomiting (36.4%), and hypokalemia (26.2%). Grade ≥3 TEAEs reported in ≥20% of patients were neutropenia (48.6%), thrombocytopenia (43.0%), febrile neutropenia (42.1%), and anemia (34.6%). Infections were reported in 57% of patients, including SAEs in 40.2% of patients. Of the 59 deaths (55.1%) reported, 23 (21.5%) were due to disease progression and 7 (6.5%) to adverse events. Within 60 days after study start, 7 deaths (6.5%) were reported. Conclusion: Ven 400 mg for 14 days plus Aza combination was well tolerated with favorable responses of CR+PR+mCR in &amp;gt;80% and HI in nearly 50% of patients with treatment-naïve HR MDS. A separate Phase 3 study of this combination is ongoing to confirm survival benefit.

Impact of Mutational Status on Clinical Response to Imetelstat in Patients with Lower-Risk Myelodysplastic Syndromes in the IMerge Phase 3 Study

CONCLUSIONS Imetelstat, a first-in-class telomerase inhibitor, showed higher rates of red blood cell (RBC) transfusion independence (TI) for ≥8 weeks, ≥24 weeks, and ≥1 year (39.8%, 28.0%, and 17.8%) than placebo (15.0%, 3.3%, and 1.7%) in the IMerge (NCT02598661) phase 3 study of patients with RBC transfusion-dependent non-del(5q) lower-risk myelodysplastic syndromes (LR-MDS) relapsed/refractory to erythropoiesis-stimulating agents (Platzbecker et al. EHA 2023. Abstr S165). To evaluate the impact of MDS-associated mutations on clinical efficacy of imetelstat, we performed next-generation sequencing of a panel of 36 genes, recurrently mutated in MDS, using DNA samples from peripheral blood collected at study entry. Further analysis of TI responses to imetelstat was performed across different mutation subgroups, defined based on genes involved in different biological functions, including the splicing process, epigenetic modifiers, transcription regulation, and receptors/kinases. Baseline mutation data were available in 165 of 178 patients (imetelstat, n = 110; placebo, n = 55; 93.2% and 91.7% of total in each group, respectively). Of patients with mutation data, 161 (97.6%) had ≥1 mutation detected, among whom, 75 (70.1%), 33 (30.8%), and 9 (8.4%) patients in the imetelstat group and 38 (70.4%), 15 (27.8%), and 7 (13%) patients in the placebo group had &amp;gt;1, &amp;gt;2, and &amp;gt;3 mutations, respectively. The ≥8-week TI rates in the imetelstat vs placebo groups were 42.7% vs 15.8% ( P = .006) for patients with &amp;gt;1 mutation, 45.5% vs 6.7% ( P = .012) for patients with &amp;gt;2 mutations, and 55.6% vs 14.3% ( P = .089) for patients with &amp;gt;3 mutations, respectively. The ≥24-week TI rates were 26.7% vs 2.6% ( P = .003), 33.3% vs 0% ( P = .014), and 33.3% vs 0% ( P = .117), respectively. In patients with mutations associated with poor prognosis ( TP53, ETV6, RUNX1, ASXL1 or EZH2), 31.8% and 9.1% of patients in the imetelstat group achieved ≥8-week and ≥24-week TI vs 0 of those in the placebo group. TP53 mutations were detected in 2 patients in each group; both patients in the imetelstat group and none in the placebo group had ≥8-week TI. Among patients with ASXL1 mutations, 5 of 18 patients (27.8%) in the imetelstat and 0 of 6 (0) in placebo group had ≥8-week TI. Among patients with ETV6 mutations, 1 of 2 (50%) in the imetelstat group and 0 of 1 patients in the placebo group had ≥8-week TI. Two patients in each group had RUNX1 mutations; none achieved TI. Imetelstat ≥8-week TI rates were 43.8%, 37.7%, 40.0%, and 80.0% for patients harboring mutated genes in the RNA spliceosome, epigenetic modifiers, transcription regulation, and receptors/kinases, respectively; ≥24-week TI was 30.2%, 27.5%, 20.0%, and 80.0%, respectively. The most frequently mutated gene was SF3B1 (125 of 165; 75.8%), the ≥8-week and ≥24-week TI rates were 48.8% vs 16.3% ( P = .001) and 35.4% vs 2.3% ( P &amp;lt; .001) with imetelstat vs placebo. In the imetelstat group, ≥8-week TI was achieved in patients with different spectrum of SF3B1 hot-spot mutations: 2 of 8 patients (25.0%) with E622D, 4 of 7 (57.1%) with R625C/L/G, 7 of 12 (58.3%) with H662Q/N/D/Y, 2 of 2 (100%) with T663P, 2 of 6 (33.3%) with K666R/T/Q/N, 18 of 41 (43.9%) with K700E, 2 of 2 (100%) with A744P, and 1 of 2 patients (50.0%) with E783K. Durable ≥24-week TI was also observed in patients with these hot-spot mutations. Other genes with mutation frequency &amp;gt;10% were TET2 (32.7%), DNMT3A (17.0%), ASXL1 (14.5%), and CUX1 (12.7%). The ≥8-week TI rates in the imetelstat group vs placebo group were 50% vs 21.4% for TET2 mutations; 31.6% vs 22.2% for DNMT3A mutations; 27.8% vs 0 for ASXL1 mutations; 35.7% vs 14.3% for CUX1 mutations (Figure). The ≥24-week TI rates were 40% vs 0, 26.3% vs 11.1%, 11.1% vs 0, and 14.3% vs 0, respectively, for those mutations (Figure). Higher RBC-TI rates were observed in patients with various baseline mutational profiles treated with imetelstat compared with placebo in IMerge. While the sample size for specific mutations was small, consistent with the observation that patients with LR-MDS have a low number of specific mutations, TI responses in patients receiving imetelstat occurred regardless of the presence of mutations associated with poor prognosis or the number of mutations. Imetelstat showed comparable TI rates across different molecularly defined subgroups, suggesting that clinical benefit of imetelstat in patients with LR-MDS is independent of the underlying molecular pattern.

The ELEMENT-MDS Trial: A Phase 3 Randomized Study Evaluating Luspatercept Versus Epoetin Alfa in Erythropoiesis-Stimulating Agent-Naive, Non-Transfusion-Dependent, Lower-Risk Myelodysplastic Syndromes

Background and Significance: Anemia is a common and debilitating symptom in patients with myelodysplastic syndromes (MDS), frequently leading to dependence on red blood cell (RBC) transfusions. Transfusion-dependent (TD) patients have worse overall survival and quality of life, and repeat transfusions are associated with complications, including iron overload. Erythropoiesis-stimulating agents (ESAs) are the standard treatment for anemia in patients with lower-risk (LR)-MDS, but many patients are ineligible for or refractory to ESAs, and responses are limited. Luspatercept, a late-stage erythroid maturation agent, is approved to treat TD patients with LR-MDS after ESA failure. In the phase 3 COMMANDS study, in ESA-naive patients with LR-MDS requiring transfusions, a significantly higher proportion of patients receiving luspatercept than epoetin alfa achieved RBC transfusion independence for ≥ 12 weeks with concurrent hemoglobin (Hb) increase ≥ 1.5 g/dL (weeks 1-24) (Platzbecker U, et al. Lancet 2023. doi: 10.1016/S0140-6736(23)00874-7). The potential of luspatercept to improve moderately severe chronic anemia and reduce RBC transfusion dependence has not yet been investigated in the majority non-transfusion-dependent (NTD) LR-MDS patient population. Preventing transfusion dependence is crucial for improving LR-MDS patient outcomes. The aim of this actively enrolling, phase 3, randomized, multicenter study is to compare the safety and efficacy of luspatercept versus epoetin alfa in reducing progression to RBC transfusion dependence in ESA-naive, NTD adult patients with anemia due to LR-MDS. Study design and methods: The ELEMENT-MDS study includes a 5-week screening period, a 96-week treatment period, an extension phase, and a post-treatment follow-up period (Figure). Target enrollment is 360 patients with anemia due to Revised International Prognostic Scoring System (IPSS-R) Very low-, Low-, or Intermediate-risk MDS. Eligible patients are ≥ 18 years of age with a confirmed MDS diagnosis, baseline serum erythropoietin (sEPO) levels ≤ 500 U/L, and symptomatic anemia defined as a score of moderate or worse on ≥ 1 Patient Global Impression of Severity (PGI-S) item (fatigue, shortness of breath, weakness, or dizziness). Participants must be RBC transfusion-independent per International Working Group 2018 criteria (no RBC transfusions within 16 weeks prior to randomization) and have baseline Hb ≤ 9.5 g/dL. Patients will be excluded if they have a del(5q) cytogenetic abnormality, unclassifiable MDS or myelodysplastic/myeloproliferative neoplasms, anemia due to reasons other than MDS, bleeding disorders, low absolute neutrophil or platelet counts, uncontrolled hypertension, previous acute myeloid leukemia diagnosis, or history of recent malignancies, among other reasons. Participants will be randomized 1:1 to receive luspatercept or epoetin alfa. Stratification factors include baseline sEPO levels, ring sideroblast status, and IPSS-R risk category. Patients will receive luspatercept once every 3 weeks at a starting dose of 1.0 mg/kg (escalation up to 1.75 mg/kg allowed) or epoetin alfa once a week at a starting dose of 450 IU/kg (escalation up to 1050 IU/kg allowed). The primary endpoint will compare the proportion of patients becoming TD (defined as requiring ≥ 3 RBC units/16 weeks) during any continuous 16-week interval in weeks 1-96. The key secondary endpoint is a Hb increase ≥ 1.5 g/dL sustained for ≥ 16 weeks during weeks 1-48. Additional secondary endpoints include time to RBC transfusion dependence, transfusion-free survival, time to achieve modified hematologic improvement-erythroid response, transfusion independence ≥ 24 weeks, and quality of life assessment. Safety endpoints include type and severity of adverse events and relationship to treatment, overall survival, and progression to high-risk MDS and acute myeloid leukemia. Summary: The results of this phase 3 study will determine the efficacy and safety of luspatercept as a therapy for ESA-naive NTD patients with LR-MDS, who have limited treatment options for anemia. The study is registered at ClinicalTrials.gov (NCT05949684) and EudraCT (2022-500430-29-00).

Characterization and Management of Cytopenias after Imetelstat Treatment in the IMerge Phase 3 Trial of Patients with Lower-Risk Myelodysplastic Syndromes (LR-MDS)

CONCLUSIONS Imetelstat, an oligonucleotide and a first-in-class telomerase inhibitor, selectively targets malignant hematopoietic stem and progenitor cells with high telomerase activity by direct binding to the RNA template. In patients with MDS the on-target effects of imetelstat are associated with the development of hematologic treatment-emergent adverse events (TEAEs). In the IMerge phase 3 trial, among patients treated with imetelstat, 68% experienced grade 3-4 neutropenia, and 62% had grade 3-4 thrombocytopenia; however, clinical consequences of grade 3-4 infection or bleeding were similar in patients treated with imetelstat and placebo (Platzbecker et al. EHA 2023. Abstr S165). Here, we report additional data on the occurrence and management of cytopenias after treatment with imetelstat. IMerge phase 3 trial (NCT02598661) is a multicenter study involving 178 patients with a median age of 72 years with red blood cell (RBC) transfusion dependency and LR-MDS relapsed/refractory to or ineligible for erythropoiesis-stimulating agents. Patients were randomized 2:1 to receive either imetelstat or placebo and stratified by prior RBC transfusion burden (4-6 or &amp;gt;6 U) and by International Prognostic Scoring System risk group. The safety population included all patients who received ≥1 dose of study drug and comprised 118 patients treated with imetelstat and 59 with placebo. TEAEs of neutropenia and thrombocytopenia with imetelstat treatment were more prevalent in cycles 1-3 (68.6% and 62.7% respectively), and their frequency decreased over time: 42.7% and 48.5% in cycles 4-6, 36.8% and 44.7% in cycles 7-12, and 31.3% and 37.5% in cycle 13 and beyond. Based on laboratory assessment, neutrophil and platelet counts decreased from baseline levels in patients treated with imetelstat versus those treated with placebo (91.5% and 95.8% vs 47.5% and 33.9%, respectively). Neutropenia decreased to a maximum of grade 4 and 3 in 55 and 29 of imetelstat-treated patients, respectively, and &amp;gt;80% of cytopenia events stabilized to grade ≤2 within 4 weeks (Figure). The median time to grade 4 neutropenia was 5.0 weeks (range,1.1-90.3 weeks) for the imetelstat group vs 23.0 weeks (range, 23.0-23.0 weeks) for the placebo group. Similarly, median time to grade 4 thrombocytopenia was 5.2 weeks (range, 2.0-29.9 weeks) with imetelstat vs 35.5 weeks (range, 28.0-43.0 weeks) with placebo. It is noteworthy that among 47 patients who achieved the primary end point of 8-week RBC transfusion independence with imetelstat, 34 (72.3%) and 28 patients (59.6%) had grade 3-4 neutropenia and grade 3-4 thrombocytopenia, respectively. In the imetelstat group, 3 patients had grade 3-4 neutropenia concurrent with grade 3-4 infections, and no patients experienced grade 3-4 thrombocytopenia associated with grade 3-4 bleeding events. There were no grade 5 cytopenias for either imetelstat or placebo groups. In the imetelstat group, cytopenias were managed with protocol-specified treatment delays and dose adjustments. Dose reductions due to neutropenia and thrombocytopenia occurred in 39 patients (33.1%) and 27 patients (22.9%), respectively. Of imetelstat-treated patients, 6 (5.1%) discontinued treatment due to neutropenia (1 case, grade 4; all others, grade 3), and 4 (3.4%) discontinued due to thrombocytopenia (1 case, grade 2; 3 cases, grade 3). In addition to dose reductions and discontinuation of imetelstat, thrombocytopenia and neutropenia were managed by cycle delays in 46.6% and 50.8% of patients, by platelet transfusions in 17.8% of patients, and by concomitant therapy with growth factor support (mostly during cycles 2-4) in 34.7% of patients. Similar patterns of imetelstat dose modifications were seen in a pooled phase 2 and phase 3 safety analysis of IMerge. In the IMerge phase 3 trial, thrombocytopenia and neutropenia were the most common and most frequently reported grade 3-4 AEs during treatment cycles 1-3. However, these AEs were generally transient, reversible, and manageable through treatment delays and dose adjustments, allowing for patients to remain on treatment and continue to experience clinical benefit. Moreover, occurrence of grade 3-4 cytopenias in responders suggests that these TEAEs do not affect the efficacy of imetelstat.

Efficacy and Safety of Recombinant Thrombopoietin Combined with Immunosuppressive Therapy for Primary Treatment of Severe Aplastic Anemia: A Single-Center, Open-Label, Randomized, Clinical Trial

Standard immunosuppressive therapy (IST) combined with eltrombopag is the first-line treatment regimen for severe aplastic anemia patients who are ineligible for allo-hematopoietic stem cell transplantation (allo-HSCT). However, there was no second-generation TPO receptor agonist available in China before 2019, and only a first-generation TPO preparation was available for clinical treatment. Although rhTPO and eltrombopag act on different receptor binding sites, the differentiation pathways are similar, so rhTPO can theoretically also stimulate hematopoietic stem cells and promote hematopoietic recovery in AA. In 2015, we used rhTPO combined with IST as the first-line treatment for SAA. The results showed that the OR and quality of response in the rhTPO group were significantly higher than those in the control group. Multivariate analysis showed that the application of rhTPO was an independent prognostic factor affecting the efficacy of IST. Based on these results, we performed a single-center, randomized, open-label, parallel-controlled clinical trial to assess the hematologic response rate and long-term safety 3, 6, and 12 months after treatment. The study was conducted between 2015 and 2019 with 188 patients with primary SAA who were randomly assigned to the control or rhTPO group (95 with IST alone and 93 with rhTPO). For rhTPO, 15000 IU was administered subcutaneously starting on day 14 after p-ATG administration and then once every other day for a total of 14 injections. The median age of the 93 patients in the rhTPO group was 33 years (range 16-67). These included 58 patients with SAA and 35 patients with very severe aplastic anemia (VSAA), which were comparable to the control group. There were no significant differences in baseline clinical parameters between groups. No significant differences were observed in the overall hematologic response rates at 3, 6, and 12 months between the rhTPO and control groups (3 months: 40.9% vs 41.1%, P = 0.979; 6 months: 52.7% vs 52.6%, P = 0.994; 12 months: 65.6% vs 63.2%, P = 0.782, respectively). The median time of platelet transfusion independent was 49 (0-376) days in the rh-TPO group and 47 (0-195) days in the control group, which was not different between the two groups ( P = 0.757). The median time of RBC transfusion independence was 47 (5-404) days and 49 (0-295) days, respectively ( P = 0.592). The median follow-up time was 64 (1.3-86.2) months. The 5-year overall survival was 86.4% (95% confidence interval [CI], 77.2-92.0%) in the rh-TPO group and 84.1% (95% CI, 74.5-90.3%, P = 0.898) in the control group. The 5-year event-free survival was 51.7% (95% CI, 41.0-61.5%) and 54.1% (95% CI, 43.5-63.6%, P = 0.947) in the two groups, respectively. No significant differences were observed in the relapse rate and clonal evolution rate between the two groups (11.5% vs. 11.7%, 4.3% vs.3.2%, repectively). Subcutaneous rhTPO injection was well tolerated by patients, with no significant adverse effects other than mild localized pain at the injection site. The patients in the rhTPO group did not have concomitant thrombotic or embolic complications; moreover, reticulo-fibrillary or collagen fibrillary hyperplasia in bone marrow was not detected in any patients at three and six months after IST. Ten patients had anti-TPO antibodies at the end of TPO treatment, with no positive anti-TPO antibodies. In conclusion, our study is the only prospective randomized controlled clinical trial in China of rhTPO combined with IST for the treatment of SAA, with no difference in the hematologic response rate of the 28-day rhTPO combination regimen compared to standard IST; however, we did confirm the safety of rhTPO at this dose. Further clinical studies are required to determine the most effective dosage and duration of rhTPO treatment.

Long-Term Evaluation of Luspatercept in Erythropoiesis-Stimulating Agent (ESA)-Intolerant/Refractory Patients (pts) with Lower-Risk Myelodysplastic Syndromes (LR-MDS) in the Phase 3 MEDALIST Study

Background: Pts with LR-MDS receiving luspatercept in the phase 3 MEDALIST trial previously reported durable, long-term red blood cell (RBC) transfusion independence (RBC-TI) (Fenaux P, et al. J Clin Oncol 2022;40[suppl 16]. Abstract 7056). MEDALIST pts were eligible to enroll in a follow-up study to evaluate long-term efficacy and safety. Aims: To report long-term efficacy and safety outcomes in ESA-refractory/intolerant pts with LR-MDS treated with luspatercept in the MEDALIST trial with an additional 26 mo of follow-up from the final MEDALIST data cutoff. Methods: Eligible pts were ≥ 18 y of age; IPSS-R-defined Very low-, Low-, or Intermediate-risk MDS with ring sideroblasts; were refractory, intolerant, or unlikely to respond to ESAs, and required regular RBC transfusions. Pts were randomized 2:1 to luspatercept (starting dose 1.0 mg/kg, with titration up to 1.75 mg/kg) or placebo. Efficacy outcomes include RBC-TI ≥ 8 wk and ≥ 16 wk. Cumulative duration of response was determined by Kaplan-Meier (KM) analysis. Rates of longest single and cumulative duration of RBC-TI ≥ 1 y and exposure-adjusted incidence rates (EAIR) of treatment-emergent adverse events (TEAEs) and AEs of special interest (AESIs) were calculated. Rates of high-risk (HR)-MDS and acute myeloid leukemia (AML) progression were calculated from LR-MDS diagnosis to HR-MDS/AML diagnosis, or to last HR-MDS/AML follow-up date for pts who did not progress. Results: As of January 2, 2023, 11 pts remained on luspatercept treatment; 8 pts randomized to luspatercept and none from placebo continued in post-treatment follow-up. The median (range) follow-up time was 39.9 (2.8-76.0) mo for luspatercept arm pts and 38.7 (1.7-68.6) mo for placebo arm pts. The median (range) duration of treatment was 50.9 (5.9-332.9) wk for luspatercept pts and 24.0 (9.0-103.0) wk for placebo pts. Seventy-five of 153 (49.0%) luspatercept pts achieved RBC-TI ≥ 8 wk during the entire treatment period and 53/75 (70.7%) had ≥ 2 response periods with a median cumulative duration of 110.14 wk (95% confidence interval [CI], 53.71-154.14; Figure A). Overall, 31/75 (41.3%) luspatercept pts had the longest RBC-TI duration ≥ 1 y, and 44/75 (58.7%) had a cumulative RBC-TI duration ≥ 1 y. In total, of the 48/153 (31.4%) pts receiving luspatercept who achieved RBC-TI ≥ 16 wk during the entire treatment period, 32/48 (66.7%) had ≥ 2 response periods with a median cumulative duration of 129.29 wk (95% CI, 79.86-240.43). Grade 3/4 treatment-related TEAEs were reported in 14/153 (9.2%; EAIR, 5.3 per 100 pt-y [PYs]) and 3/76 (3.9%; EAIR, 6.6 per 100 PYs) luspatercept and placebo pts, respectively; TEAEs of any grade leading to permanent treatment discontinuation were reported in 24/153 (15.7%; EAIR, 8.6 per 100 PYs) luspatercept and 6/76 placebo pts (7.9%; EAIR, 13.0 per 100 PYs). The most common TEAEs of any grade reported in &amp;gt; 5% of luspatercept pts were fatigue (47/153 [30.7%]; EAIR, 22.1 per 100 PYs; vs placebo, 11/76 [14.5%]; EAIR, 27.1 per 100 PYs), diarrhea (47/153 [30.7%]; EAIR, 23.5 per 100 PYs; vs placebo, 8/76 [10.5%]; EAIR, 18.4 per 100 PYs), asthenia (41/153 [26.8%]; EAIR, 18.8 per 100 PYs; vs placebo, 9/76 [11.8%]; EAIR, 21.5 per 100 PYs), peripheral edema (40/153 [26.1%], EAIR, 17.6 per 100 PYs; vs placebo, 13/76 [17.1%]; EAIR, 32.0 per 100 PYs), and back pain (38/154 [24.7%]; EAIR, 16.8 per 100 PYs; vs placebo, 5/76 [6.6%]; EAIR, 11.7 per 100 PYs; Figure B). During the entire treatment period, 26/44 (59.1%), 9/23 (39.1%), and 12/86 (14.0%) pts who received ≤ 1 mg/kg, 1.33 mg/kg, and 1.75 mg/kg luspatercept, respectively, reported fatigue of any grade. No new progression to HR-MDS or AML events have been reported since the last data cutoff (Santini V et al. Blood 2022;140[suppl 1]:4079-4081). Conclusions: Pts with LR-MDS who received luspatercept for &amp;gt; 2 years longer than in the original MEDALIST study, continued to experience sustained periods of RBC-TI with more than half of pts experiencing cumulative RBC-TI for ≥ 1 year. The long-term safety profile of luspatercept is consistent with previous shorter-term reports, and AEs were mostly lower grade with rates of fatigue decreasing with increasing luspatercept dose. These data demonstrate the long-term efficacy and safety of luspatercept in pts with LR-MDS intolerant/ineligible for ESA treatment.

Efficacy and Safety of Luspatercept Versus Epoetin Alfa in Erythropoiesis-Stimulating Agent (ESA)-Naive Patients (Pts) with Transfusion-Dependent (TD) Lower-Risk Myelodysplastic Syndromes (LR-MDS): Full Analysis of the COMMANDS Trial

Introduction: ESAs are an established treatment (tx) for pts with TD LR-MDS and endogenous serum erythropoietin (sEPO) levels ≤ 500 U/L; however, eligible pts often do not respond, or the response duration is limited. Luspatercept is approved in the US and EU to treat anemia due to LR-MDS after ESA failure. The preplanned interim analysis of the phase 3 COMMANDS trial (NCT03682536), comparing luspatercept with epoetin alfa in ESA-naive TD pts with anemia due to LR-MDS (with or without ring sideroblasts [RS]) showed for the first time the superiority of another therapy over ESAs in improving red blood cell transfusion independence (RBC-TI) rates (Platzbecker U, et al. Lancet 2023. doi:10.1016/S0140-6736[23]00874-7). Here we report the full efficacy and safety analysis of the COMMANDS trial. Methods: Eligible pts were ≥ 18 y of age, had Revised International Prognostic Scoring System-defined LR-MDS with &amp;lt; 5% bone marrow blasts, sEPO &amp;lt; 500 U/L, and were TD (received 2-6 RBC U/8 wk for ≥ 8 wk before randomization). Pts were randomized 1:1 to luspatercept (1.0-1.75 mg/kg) subcutaneously (SC) Q3W, or epoetin alfa (450-1050 IU/kg) SC Q1W for ≥ 24 wk and stratified by baseline RBC transfusion burden (&amp;lt; 4 vs ≥ 4 RBC U/8 wk), RS status (RS+ vs RS−), and sEPO (≤ 200 vs &amp;gt; 200 U/L). The primary endpoint was the achievement of RBC-TI ≥ 12 wk with a concurrent mean hemoglobin (Hb) increase ≥ 1.5 g/dL (wk 1-24). Key secondary endpoints (wk 1-24) included achievement of RBC-TI ≥ 12 and for 24 wk and hematologic improvement-erythroid (HI-E) ≥ 8 wk. Other endpoints included duration of RBC-TI ≥ 12 wk, progression to acute myeloid leukemia (AML), and safety. Results: As of Mar 31, 2023, 182 pts were randomized to luspatercept and 181 to epoetin alfa, with a median (range) tx duration of 51.3 (3-196) and 37.0 (1-202) wk and median (range) follow-up of 17.2 (1-46) and 16.9 (0-46) months, respectively. The primary endpoint was achieved by110 (60.4%) pts in the luspatercept arm versus 63 (34.8%) in the epoetin alfa arm ( P &amp;lt; 0.0001). Subgroup analysis of the primary endpoint response showed that response rates achieved with luspatercept versus epoetin alfa, respectively, were greater for SF3B1-mutated and non-mutated pts (Table), greater for pts with baseline sEPO ≤ 200 U/L and with baseline sEPO &amp;gt; 200 to &amp;lt; 500 U/L (Table), and greater for RS+ pts (Table). The response rates were comparable between tx arms for RS− pts (Table). RBC-TI ≥ 12 wk was achieved by 124 (68.1%) and 88 (48.6%) pts in the luspatercept and epoetin alfa arms, respectively, RBC-TI for 24 wk by 87 (47.8%) and 56 (30.9%) pts, and HI-E ≥ 8 wk by 135 (74.2%) and 96 (53.0%) pts. The median (95% CI) duration of RBC-TI ≥ 12 wk was longer with luspatercept versus epoetin alfa (128.1 wk [108.3-not estimable (NE)] versus 89.7 wk [5.9-157.3]; HR, 0.534; Figure), and longer for clinically relevant subgroups, including RS+ and RS−. The median duration of tx was longer in the luspatercept arm compared with the epoetin alfa arm (51.3 versus 37.0 wk). Five (2.7%) and 6 (3.3%) pts in the luspatercept and epoetin alfa arms, respectively, progressed to AML. Overall, 178 (97.8%) and 165 (92.2%) pts receiving luspatercept and epoetin alfa reported tx-emergent adverse events (TEAEs) of any grade; 107 (58.8%) and 88 (49.2%) pts reported grade 3/4 TEAEs, respectively. The most common any-grade TEAEs in either arm (≥ 10% of pts) were diarrhea (17.6% luspatercept vs 14.0% epoetin alfa), COVID-19 (14.8% vs 15.6%), asthenia (13.7% vs 16.2%), and anemia (12.1% vs 10.6%). TEAEs of interest were reported by 105 (57.7%) and 81 (45.3%) pts receiving luspatercept and epoetin alfa, respectively, with asthenia including fatigue, malaise, and lethargy (30.8% vs 24.6%), hypertension (15.9% vs 9.5%), malignancies and premalignant disorders (14.3% vs 12.8%), kidney toxicity (8.8% vs 6.7%), and injection site reactions (6.6% vs 2.2%), occurring in &amp;gt; 5% pts. In both tx arms, rates of on-tx deaths (8.2% for luspatercept and 7.2% for epoetin alfa) and post-tx deaths (13.2% and 13.4%) were similar. Conclusions: Results of this full analysis confirm the findings from the interim analysis; RBC-TI duration and erythroid responses achieved with luspatercept are superior compared with epoetin alfa. Luspatercept safety results were consistent with previous MDS studies. These data show that luspatercept could represent a new standard of care for pts with TD LR-MDS.

Red Blood Cell Transfusion Independence Status Is an Independent Predictor of Survival: A Post Hoc Time-Dependent Analysis of the Phase 3 Simplify-1, Simplify-2, and Momentum Trials

Introduction: The management of anemia in myelofibrosis (MF), a chronic progressive myeloproliferative neoplasm, remains an ongoing medical need as it is present in approximately 30% of patients (pts) at diagnosis and &amp;gt;50% after 1 year, contributing to negative impacts such as fatigue, medical complications, and poor quality of life. Furthermore, anemia and resulting transfusion need are independent predictors of poor prognosis. Momelotinib (MMB) is a Janus kinase (JAK) 1/JAK2/activin A receptor type 1 (ACVR1) inhibitor that has demonstrated spleen, symptom, and anemia benefits, including increases in hemoglobin (Hb) and reduction or elimination of red blood cell (RBC) transfusion requirements in pts with MF. Data from the phase 3 SIMPLIFY-1 (S1), SIMPLIFY-2 (S2), and MOMENTUM studies have shown an association between transfusion independence at wk 24 and prolonged overall survival (OS) with MMB (Mesa R, et al. Leukemia. 2022; Verstovsek S, et al. ASH 2022. Poster 3028). Because these analyses did not adjust for additional prognostic factors or effect modifiers nor potential longitudinal changes in transfusion status over time, the impact of transfusion status on OS has not been fully characterized. Here, we describe an analysis investigating the prognostic influence of RBC transfusion status over time and other covariates on OS from the S1 (NCT01969838), S2 (NCT02101268), and MOMENTUM (NCT04173494) studies irrespective of the treatment received. Methods: These treatment-agnostic OS analyses incorporated data from 3 multicenter, international, randomized trials investigating MMB vs an active comparator. Analyses were performed in the safety populations of S1 (N=430; MMB vs ruxolitinib [RUX], JAK inhibitor [JAKi] naive), S2 (N=156; MMB vs best available therapy [88.5% RUX], JAKi experienced), and MOMENTUM (N=195; MMB vs danazol, JAKi experienced). In the current analysis, which accounts for evaluations of transfusion status every 4 wk, time-dependent covariates (RBC transfusion status, categorized as either transfusion independent [TI; absence of RBC transfusion and no Hb level &amp;lt;8 g/dL in the prior 12 wk] or non-TI [not satisfying the criteria for TI]) and fixed baseline covariates (age, sex, MF subtype, Eastern Cooperative Oncology Group [ECOG] status, JAK2 mutational profile, Total Symptom Score, International Prognostic Scoring System [IPSS] score for S1, Dynamic IPSS [DIPSS] score for S2 and MOMENTUM, platelet count, baseline spleen volume as assessed by central reading of magnetic resonance imaging/computed tomography scan) were evaluated to determine their prognostic impact. An extended Cox model was used to generate an overall hazard ratio (HR) using all available follow-up time for each study, and independent variables were retained if a backward variable selection method determined that they were significantly associated with OS. Results: Significant covariates associated with survival across the 3 trials are presented in the table, with RBC transfusion status as a consistent prognostic variable. In S1, age, platelet count, and baseline spleen volume were also significantly associated with OS, and in S2, significant covariates included age, baseline spleen volume, and DIPSS. In MOMENTUM, only RBC transfusion status was significantly associated with survival. When accounting for differences in prognostic factors and effect modifiers as well as changes in transfusion status over time, results from MOMENTUM demonstrate a strong and significant relationship between transfusion status and OS (HR, 5.18; 95% CI, 1.86-14.47; P=.0017), suggesting that non-TI pts have a higher risk of all-cause mortality of more than 5 times that of TI pts. Similar results with respect to the survival benefits of TI status were observed in both S1 (HR, 3.32; 95% CI, 2.31-4.78; P&amp;lt;.0001) and S2 (HR, 1.87; 95% CI, 1.07-3.29; P=.0287). Conclusions: These data demonstrate that when accounting for differences in known prognostic factors and effect modifiers as well as changes in RBC transfusion status over time, a consistent and statistically significant relationship was observed between transfusion status and OS across all 3 phase 3 MMB trials. Consistent with inclusion of transfusion status in DIPSS-plus risk assessment, these data validate TI status as a clinically relevant and meaningful endpoint that is prognostic for survival in JAKi-naive and JAKi-experienced disease settings.

Early Initiation of Oral Therapy with Cyclosporine and Eltrombopag for Treatment Naïve Severe Aplastic Anemia: Interim Results of a Phase II Trial

Introduction: Severe aplastic anemia (SAA), a life-threatening bone marrow failure disease, is treated with allogeneic bone marrow transplantation or immunosuppression (IST). Pancytopenia meeting “Camitta” criteria and an empty bone marrow (&amp;lt;30% cellularity) establish the diagnosis of SAA. However, neither diagnosis nor therapeutic interventions are straightforward, resulting in delays of therapy. SAA must be differentiated from hematologic malignancy, and constitutional forms should be excluded by functional or genetic testing. Administration of IST usually occurs at a tertiary care center, and in younger patients' evaluation for BMT is first required. Ongoing immune mediated destruction of stem cells further depletes marrow reserve and increases regenerative stress with such delays. In this phase II study, we tested the feasibility and safety of early initiation of cyclosporine (CSA) to block T cells and eltrombopag (EPAG) to stimulate hematopoiesis followed by standard of care therapies to expedite treatment (NCT04304820). Methods: Twenty-six patients with treatment-naive SAA were enrolled since 2020. Patients were 3 years or older and median age was 35 years. Exclusion criteria included a diagnosis or high clinical suspicion for inherited disease or evidence of myeloid neoplasm. To ensure rapid initiation of therapy, enrollment was not dependent on pending specialized tests (telomere length, chromosomal breakage, cytogenetics, or genomics). Lower dose CSA (2mg/kg) and full dose EPAG were initiated after confirming eligibility. Upon completion of evaluation and confirmation of acquired SAA diagnosis, all subjects received standard IST (horse ATG, CSA, and EPAG; Figure 1A). Primary feasibility endpoint assessed a composite measure of misdiagnosis, non-compliance, and treatment-related serious adverse events (TRSAE) during oral therapy. Secondary endpoints were efficacy at 6 months, relapse, clonal evolution, and overall survival. Results were compared to a historical cohort of 139 patients treated with hATG, CSA, and EPAG initiated the same day (NCT01623167). Results: All patients completed the protocol-defined treatment period, with median time on oral therapy of 17 days (range 0 - 86 days). All subjects ultimately were confirmed to have acquired SAA (no misdiagnoses), all tolerated oral treatment well without any TRSAE, and patients were compliant with local and study-site follow-up. Thus, there were zero events for the primary feasibility endpoint. A single SAE during oral treatment occurred in subject #1, enrolled at the height of the COVID pandemic and was severely ill with persistently positive COVID-19 PCR and recurrent ileitis requiring hospitalization care; his time to standard IST was the longest (86 days). There was significant increase in absolute neutrophil count (ANC; median 0.315x10 3/mL vs 0.570, p=0.041) in a brief interval of oral therapy prior to receiving hATG. There was also a trend towards improvement in absolute reticulocyte count (29x10 3/mL vs. 35.8) and a decrease in absolute lymphocyte count (1.5x10 3/mL vs. 1.3; Figure 1B). Compared to historical cohort, less patients (19% vs 52%) had very SAA (ANC &amp;lt;200 K/uL); age, sex, race, and pre-treatment blood counts were similar in two cohorts. Hematologic response occurred in 68% at 6 months with 45% complete responses, rates similar to the historical cohort (80% and 40%, respectively). Time to platelet and red blood cell transfusion independence was 43 and 51 days, respectively. Only age (18-40 years) was predictive for 6 month response. With median follow-up of 396 days, the cumulative incidence of relapse at 2 years was 17%, lower than in the historical cohort (27%). Clonal evolution to secondary myeloid malignancy was not increased compared to historical cohort; one subject had myelodysplastic syndrome with excess blasts 1 with deletion 20q, and two had transient trisomy 8 without dysplasia. Overall survival was 96.2%; no deaths occurred during study treatment period of oral medications only. Conclusion: Early initiation of CSA and EPAG is a feasible and safe approach to rapidly treat patients with SAA as a bridge to standard therapies and it may lead to improved blood counts, in turn, decreasing early infectious complications. Hematologic response was comparable to our historic cohort. Rates of long-term complications need to be confirmed in a larger cohort with ongoing study enrollment.

Net Clinical and Quality of Life Benefit of Luspatercept in Transfusion-Dependent MDS: A Win Ratio Analysis Using Data from the Phase 3 MEDALIST Study

Background: Patients with transfusion-dependent (TD) myelodysplastic syndromes (MDS) often experience various anemia-related symptoms and functional impairments. Treatments reducing red blood cell (RBC) transfusion burden could impact these symptoms and/or functions to varying degrees depending on patients' conditions at baseline and warrants the use of composite endpoints, including both clinical outcomes and patient-reported outcomes (PROs) to fully capture these benefits. However, conventional statistical approaches may not satisfactorily assess composite outcomes, especially when the components of the composite outcomes have different types of scales and/or degrees of importance to stakeholders. The win ratio (WR) approach, one of the generalized pairwise comparison methods commonly used for assessing treatments in cardiovascular diseases, offers hierarchical structure, statistical power, and flexibility to address these challenges. Objective: This exploratory analysis used the WR approach to assess the net benefit of luspatercept vs. placebo on composite clinical/PRO endpoints using data from the MEDALIST study. Methods: Four different WR scenarios were performed, in each of which every possible patient-to-patient pair between the luspatercept and placebo arms was compared on a set of relevant clinical/PRO endpoints in a pre-specified order of assumed priority from patients' perspectives, accompanied with a pre-determined rule to assign a win, loss, or tie for luspatercept in each pairwise comparison on each endpoint. If a win or loss could not be determined on a given endpoint, then the next endpoint in the hierarchy was evaluated until a win or loss occurred. Otherwise, if all pre-specified endpoints were evaluated, a tie was assigned. The scenarios considered two clinical endpoints: RBC-transfusion independence [TI] ≥8 weeks over Weeks 1-24 and RBC-TI over Weeks 1-24. PRO endpoints included changes from baseline to the end of Week 24 in five key domains of the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), categorized as improvement (≥10-point improvement), stable (10 &amp;gt; change &amp;gt;-10), or worsening (≥10-point worsening). Improvement was considered a better outcome than stable and worsening, and stable was considered better than worsening when determining a win or loss for luspatercept on each of the PRO endpoints. The four different scenarios of composite clinical/PRO endpoints and their order of priority, shown in the Table were pre-specified for assessment . The WR (nominal 95% CI, p-value) for luspatercept on each scenario of the composite clinical/PRO endpoints was calculated as the total number of pairs with a win divided by the total number of pairs with a loss. A WR &amp;gt;1 indicates that luspatercept is more favorable than placebo. Results: 153 patients randomized to the luspatercept arm were compared to 76 patients randomized to the placebo arm, for a total of 11,628 pairwise comparisons within each WR analysis. In all four scenarios, WRs were nominally statistically significantly in favor of luspatercept ( Table). Most wins favoring luspatercept were attributed to wins on the clinical endpoint. Among those pairs who tied on the clinical endpoint, the luspatercept arm experienced more wins (or tied) in almost all of the five PRO endpoints. WRs were similar whether PRO endpoints were prioritized over others or not. Conclusions: The analysis findings indicate that, for two randomly selected patients with low-risk TD MDS, the odds that the patient treated with luspatercept would have a better outcome (if not tied) than the patient with placebo, is significantly higher than 1, ranging between 1.51 to 1.90. The analysis also shows that when multiple clinical and PRO endpoints, especially with different importance to stakeholders, are considered to provide a comprehensive treatment benefit, WR can be a useful and valuable approach for making this evaluation.

Estimating Transfusion-Related Medical Costs and Associated Time Burden in Patients with Myelofibrosis: A Comparison of Momelotinib Vs Ruxolitinib Based on Simplify-1

Introduction: Myelofibrosis (MF) is a myeloproliferative neoplasm characterized by splenomegaly, debilitating symptoms, and bone marrow fibrosis. Transfusion-dependent (TD) anemia is present in one-quarter of patients (pts) with MF at diagnosis and becomes more common over time. Transfusion dependence imposes a high cost burden on healthcare systems, with annual total medical costs up to 9 times higher for TD pts than for non-TD pts (Gerds A, et al. ASH 2022. Abstract 1729). Momelotinib (MMB) is a Janus kinase (JAK) 1/JAK2/activin A receptor type 1 inhibitor that has demonstrated symptom, spleen, and anemia benefits in pts with MF across 3 phase 3 trials. Evidence in JAK inhibitor-naive pts comes from SIMPLIFY-1 (NCT01969838), a randomized, double-blind, phase 3 trial of MMB vs ruxolitinib (RUX). Eligible pts had International Prognostic Scoring System high-risk or intermediate-2-risk MF, or intermediate-1-risk MF associated with symptomatic splenomegaly, hepatomegaly, or anemia (hemoglobin &amp;lt;10 g/dL) and/or unresponsiveness to available non-JAK inhibitor therapy. MMB was associated with higher red blood cell (RBC) transfusion independence rates (66.5% vs 49.3%), lower transfusion dependence rates (30.2% vs 40.1%), and fewer RBC units transfused (median of zero units/month vs 0.4 units/month) compared with RUX by week 24. This study estimated the projected differences between MMB and RUX in total medical costs as well as cost and time burden associated with outpatient transfusion visits, based on results from SIMPLIFY-1, in all pts with MF and separately in those aged ≥65 years. Methods: Analyses were based on transfusion status (TD, transfusion independent [TI], or transfusion requiring [TR]) and mean rates of outpatient transfusion visits over 24 weeks in SIMPLIFY-1. TD was defined as ≥4 RBC units transfused or hemoglobin &amp;lt;8 g/dL in the prior 8 weeks, TI was defined as no RBC transfusions and all hemoglobin ≥8 g/dL in the prior 12 weeks, and TR was defined as being neither TD nor TI. Projected cost offsets for MMB relative to RUX were calculated based on observed transfusion status and rates over 24 weeks from SIMPLIFY-1 combined with cost estimates for TD vs TI/TR from the IBM MarketScan Database used to inform commercial health plans. Projected time savings were calculated similarly using transfusion rates from SIMPLIFY-1 and previously reported time burden estimates for transfusion visits in pts with TD β-thalassemia (Knoth RL, et al. EHA2022. Poster P1741). For pts aged ≥65 years, individual pt data from SIMPLIFY-1 and cost estimates from the Medicare fee-for-service database were used instead. Results: Based on the IBM MarketScan Commercial Database, projected average annual total medical cost savings based on week 24 transfusion status with MMB vs RUX were $20,215 per pt with baseline TD status and $23,991 per pt with baseline TI/TR status. Fewer outpatient transfusion visits with MMB vs RUX resulted in projected annual savings of $25,704 per pt with baseline TD status and $12,083 per pt with baseline TI/TR status. Among pts with baseline TD status, projected annual time savings in transfusion visits for MMB vs RUX (147 vs 253 hours) totaled 106 hours per pt (42 hours, preparation and waiting; 50 hours, transfusion and recovery; 15 hours, travel), a 42% reduction for MMB vs RUX. In the subgroup analysis that focused on pts aged ≥65 years, based on the Medicare fee-for-service database, projected average annual total medical cost savings with MMB vs RUX were $11,102 per pt with baseline TD status and $17,373 per pt with baseline TI/TR status. Fewer outpatient transfusion visits with MMB vs RUX resulted in projected annual savings of $28,826 per pt with baseline TD status and $18,255 per pt with baseline TI/TR status. Among pts aged ≥65 years with baseline TD status, projected annual time savings in transfusion visits accounted for MMB vs RUX (160 vs 279 hours) totaled 119 hours per pt (47 hours, preparation and waiting; 56 hours, transfusion and recovery; 16 hours, travel), a 43% reduction for MMB vs RUX. Conclusions: Reductions in transfusion dependence and transfusion visits for MMB vs RUX were associated with projected healthcare system savings in transfusion costs and transfusion-related time burden in JAK inhibitor-naive pts with MF, including in subgroup analyses of pts aged ≥65 years.

FORTITUDE: A Phase 2 Open-Label Study in Progress to Evaluate Etavopivat for the Treatment of Anemia in Patients with Lower-Risk Myelodysplastic Syndromes

Background: Most patients with lower-risk myelodysplastic syndrome (LR-MDS) develop anemia and a high proportion of patients become dependent on red blood cell (RBC) transfusions. MDS-related anemia is associated with low hemoglobin (Hb) levels, iron overload and poor quality of life. Erythropoiesis-stimulating agents and other drugs, including lenalidomide, luspatercept and imetelstat (an investigational product), can lead to RBC transfusion independence and improve Hb levels in many patients; however, responses are generally transient and novel treatments are needed for this population. Etavopivat is an investigational, once-daily, selective erythrocyte pyruvate kinase (PKR) activator in development for the treatment of sickle cell disease (SCD) and anemia in patients with LR-MDS. In a phase 1 study in adult and adolescent patients with SCD by Saraf et al. HemaSphere. (2022), etavopivat 400 mg once daily was considered well tolerated and showed sustained Hb increases up to 12 weeks for most patients. Additional studies in healthy volunteers and patients with SCD support an acceptable safety profile together with improved RBC health and function during continuous treatment with etavopivat. In patients with LR-MDS, ineffective hematopoiesis may be due, in part, to insufficient ATP production, leading to increased erythroid lineage apoptosis. By activating PKR, etavopivat may improve RBC health and function by stimulating energy production (increasing ATP levels), increasing Hb levels (decreasing anemia), and decreasing erythroid lineage apoptosis. Aims:Describe the design of a multicenter, open-label, phase 2 study (FORTITUDE; NCT05568225) evaluating hematologic improvements in patients with very low-, low- and intermediate-risk MDS during treatment with etavopivat. Study design:Key eligibility criteria include age ≥18 years; very low-, low- and intermediate-risk MDS per the Revised International Prognostic Scoring System; and anemia defined by mean Hb &amp;lt;10.0 g/dL and &amp;lt;3 RBC transfusions &amp;lt;16 weeks prior to first dose for non-transfusion-dependent (NTD) patients or ≥3 units of RBCs for anemia &amp;lt;16 weeks prior to first dose for transfusion-dependent (TD) patients. Key exclusion criteria include MDS associated with del 5q cytogenetic abnormality and known TP53 abnormality, history of acute myeloid leukemia, and an absolute neutrophil count &amp;lt;0.5 × 10 9/L. Additional exclusion criteria include prior treatment with azacitidine; decitabine; erythropoietin, other hematopoietic growth factor treatment or lenalidomide within 30 days of Day 1 or anticipated to be required during the study; and luspatercept within 30 days of Day 1 for NTD patients and within 16 weeks of Day 1 for TD patients. Patients will receive etavopivat 400 mg once daily for at least 48 weeks. Treatment may be continued beyond 48 weeks in patients demonstrating clinical benefit. The primary objective of the study is to assess hematologic improvements based on an erythroid response over any continuous period ≥8 weeks within 24 weeks on etavopivat treatment in patients with LR-MDS. The primary endpoint will be based on the combined incidence of: ≥1.5 g/dL increase in Hb from baseline maintained for ≥8 consecutive weeks for NTD patients; absence of any transfusion for ≥8 consecutive weeks for low transfusion-burden patients; and reduction by ≥50% of RBC units for ≥8 consecutive weeks for high transfusion-burden patients. Safety, tolerability, pharmacokinetic, and pharmacodynamic properties of etavopivat will be evaluated. FORTITUDE is open for enrollment in Canada, France, Germany, and the USA. Planned enrollment includes approximately 15 patients in each of the three transfusion requirement-based groups (Figure). Statistical analysis: The primary endpoint (pooled incidence) will be tested with a one-sided Fisher's exact test at the significance level of 0.025 where 0.2 is the assumed null proportion. Summary:Etavopivat is a novel, investigational, once-daily, selective PKR activator with the potential to improve RBC health and lifespan. This phase 2 study will assess the safety of etavopivat and its impact on Hb levels and RBC transfusion burden in patients with LR-MDS and anemia.

Treatment of refractory or relapsed myelodysplastic neoplasms with luspatercept: a multicenter Chinese study.

Few effective therapies are available to treat patients with relapsed/refractory myelodysplastic neoplasms (MDS). Luspatercept was shown to display good efficacy in a phase 3 clinical trial for lower-risk MDS (LR-MDS) patients, yet real-world data are limited, especially in China. Therefore, data from patients diagnosed as having MDS with low blasts and SF3B1 mutation (MDS-SF3B1) and MDS with SF3B1 mutation and thrombocytosis were retrospectively analyzed. Of the 23 enrolled patients, 17 (73.9%) were males (median age 67years: range 29 to 80years). Previously, a total of 22 (95.7%) patients had received recombinant human erythropoietin (rhEPO), 9 (39.1%) roxadustat, 7 (30.4%) lenalidomide and 3 (13.0%) hypomethylating agents (HMA). The median treatment time was 22.9weeks (9.0-32.4). At week 12, 60.9% (14/23) of the patients achieved a hematologic improvement-erythroid (HI-E) response. Red blood cell transfusion independence (RBC-TI) for ≥ 8weeks was found in 57.1% (8/14) of transfusion-dependent patients. The median hemoglobin concentration was 84g/L, and patients had significantly higher hemoglobin concentrations after 12weeks of treatment (P < 0.001). It is noteworthy that responders had a greater reduction in serum ferritin (P = 0.021). Those with serum EPO < 500IU/L at baseline tended to have a higher HI-E rate (P = 0.081), but only patients in non-transfusion and low transfusion burden (LTB) subgroups had statistical differences (P = 0.024). The most commonly occurring adverse events were blood bilirubin increase (17.4%), fatigue (13.0%) and dizziness (13.0%). Luspatercept was effective and tolerated well in refractory LR-MDS-SF3B1 patients. In particular, baseline non-transfusion and LTB patients exhibited a greater response rate to treatment.