Treatment-emergent Grade Research Articles

Open-Label, Multicenter, Phase I Study to Assess Safety and Tolerability of Adavosertib Plus Durvalumab in Patients with Advanced Solid Tumors.

Adavosertib (AZD1775) is a small-molecule Wee1 inhibitor. Durvalumab is a PD-L1 inhibitor. The safety, tolerability, pharmacokinetics, and preliminary antitumor activity of adavosertib plus durvalumab were evaluated in patients with refractory solid tumors to define the maximum tolerated dose (MTD) and recommended phase II dose (RP2D). This phase 1, non-randomized, open-label study determined MTD/RP2D using dose-escalation cohorts. Eligible patients had histologically confirmed tumors refractory to standard therapy or for which no standard of care existed. A total of 55 patients received adavosertib with durvalumab. Overall, 3/52 evaluable patients experienced dose-limiting toxicities (DLTs; two grade 3 nausea, one grade 3 diarrhea that did not respond to care within 48 h). The most frequent (in > 5% of patients) treatment-emergent grade ≥ 3 toxicities were fatigue, diarrhea, nausea, anemia, and abdominal pain. MTD for twice-daily (bid) adavosertib dosing was oral adavosertib 150 mg bid (3 days on/4 days off; treatment days 15-17 and 22-24 of a 28-day cycle) with intravenous durvalumab 1500 mg four times a week (Q4W), which was also the RP2D. MTD for once-daily (qd) adavosertib dosing was oral adavosertib 300 mg qd (5 days on/2 days off; treatment days 15-19 and 22-26 of a 28-day cycle) with intravenous durvalumab 1500 mg Q4W. This study defined the MTD/RP2D of adavosertib plus durvalumab in patients with advanced solid tumors. The safety profile of adavosertib with durvalumab was consistent with the known safety data of each agent. Findings provide preliminary evidence of limited antitumor activity of adavosertib plus durvalumab. ClinicalTrials.gov, NCT02617277 (registration: 30 November 2015).

Study APV20002: Safety and Efficacy Results Through Week 684 for Pediatric Participants Living with HIV-1 Treated with Ritonavir-Boosted Fosamprenavir Oral Solution-Based Antiretroviral Therapy.

APV20002 was a multicenter, international, open-label study that began in 2003 investigating the pharmacokinetics, efficacy, and safety of ritonavir-boosted fosamprenavir (FPV/r) oral solution (OS) in combination with nucleoside reverse transcriptase inhibitor-based antiretroviral therapy (ART) in participants living with HIV-1 aged 4 weeks to <2 years with a primary endpoint at Week 48 (48W). Participants in APV20002 could continue in the study post-48W until FPV OS was locally available in their countries. Children were required to discontinue after reaching >39 kg or if FPV OS had no clinical benefit. Fifty-nine participants were enrolled; 5/59 received a single FPV OS visit for pharmacokinetic determinations. Most (38/54; 70%) were antiretroviral experienced; 39/59 participants had >48 weeks on treatment, 4/39 of whom discontinued after 48 weeks due to an adverse event (AE). At 48W, 88% of participants had HIV-1 RNA <400 copies/mL by Observed analysis; the proportion with HIV-1 RNA <400 copies/mL remained high (84%-100%) through Week 684. The median CD4+ cell count was 1,235 cells/mm3 [n = 51] at baseline, 1,690 cells/mm3 (n = 41) at Week 48, and 1,280 cells/mm3 (n = 21) at Week 180. From baseline to Week 684, 54/59 (92%) participants had ≥1 treatment-emergent AE regardless of causality; 42/59 (71%) had a treatment-emergent grade 2-4 AE, predominantly maximum toxicity: grade 2; 21/59 (36%) and 21/59 (36%) had severe or grade 3/4 AEs. From baseline to Week 684, 14/54 (26%) participants met virologic failure (VF) criteria, 9/14 before 48W. HIV from 1/9 VFs through 48W developed treatment-emergent reduced susceptibility to FPV and 1/9 to lamivudine/emtricitabine. Post-48W, 4/5 participants with VF had phenotype results; all were still susceptible to all study drugs at VF. In conclusion, FPV OS-based ART was efficacious and generally well tolerated in this long-running pediatric study through 684 weeks of treatment, with a safety profile consistent with experience in adults and older children.

Interim results of the randomized phase 2 cohort of study FW-2020-01 assessing the efficacy, safety and pharmacodynamics of CM24 in combination with nivolumab and chemotherapy in advanced/metastatic pancreatic cancer.

LBA4143 Background: The novel monoclonal antibody CM24 blocks the activity of Carcinoembryonic Antigen Cell Adhesion Molecule 1 (CEACAM1), known to have key roles in cancer progression, immune evasion, and metastasis. We present the interim efficacy and safety data from the global multi-center, open label, randomized Phase 2 study (NCT 04731467) in patients (pts) with advanced/metastatic pancreatic ductal adenocarcinoma (PDAC) who progressed after 1st line therapy, treated with CM24, nivolumab (nivo) and chemotherapy vs. chemotherapy (CH). Methods: Patients with advanced/metastatic PDAC progressing after 1 prior line of systemic therapy including fluoropyrimidine/irinotecan or gemcitabine/nab-paclitaxel, having ≥1 measurable lesion, ≥18-year-old, ECOG ≤1 and adequate organ function were randomized 1:1 based on the class of prior CH received. Randomization was either to the experimental groups (EX) receiving CM24 (20mg/kg, q2wk), nivo (240mg/kg, q2wk) with one of the following CH regimens, liposomal irinotecan, 5 fluorouracil and leucovorin (Nal-IRI; q2wk) or gemcitabine/nab-paclitaxel (gem/nab; q1wk x3) or the control groups (C) with one of the CH regimens alone. This is a Bayesian design with an overall planned sample size of 60 pts with Overall Survival (OS) as the primary endpoint. Secondary endpoints include progression free survival (PFS), objective response rate (ORR) and disease control rate (DCR). An interim estimate of PFS HR, ORR and DCR based on data cut-off date of 21 Feb 2024 is reported. The analysis compares the EX vs. the respective C arm using log-rank test stratified by CH regimen. Results: A total of 63 PDAC pts were evenly randomized across the study arms. At data cut-off date, a total of 18 pts, 9 per treatment regimen remain on treatment. The median follow-up time for the Nal-IRI regimen is 6.3 months (95% CI: 5.5-8.4) and 5.2 months (95% CI: 4.0-6.7) for the gem/nab regimen. Median PFS ORR and DCR for the Nal-IRI EX arm were 3.8m (1.9-5.1; HR 0.70; p=0.213), 18.8% and 62.6%, and for the Nal-IRI C arm 1.9m (1.8-5.6), 6.3% and 40%, respectively (Table). Data for the gem/nab regimen and OS data for both regimens are not mature. Overall Grade ≥3 AE rate was 50% in the Nal-IRI EX arm and 13% in the C arm. The most common treatment-emergent grade ≥3 AEs EX vs. C were diarrhea (18.8% vs 6.7%), fatigue (18.8% vs 6.7%) and anemia (6.3% vs 0%). Conclusions: The interim analysis suggests that the combination of CM24/nivo/Nal-IRI/5FU/LV has a manageable safety profile with a longer PFS supported by higher ORR and DCR. OS Data continues to mature and will be reported once available. Clinical trial information: NCT04731467 . [Table: see text]

Capivasertib in combination with enzalutamide for metastatic castration resistant prostate cancer after docetaxel and abiraterone: Results from the randomized phase II RE-AKT trial

BackgroundPTEN loss and aberrations in PI3K/AKT signaling kinases associate with poorer response to abiraterone acetate (AA) in metastatic castration-resistant prostate cancer (mCRPC). In this study, we assessed antitumor activity of the AKT inhibitor capivasertib combined with enzalutamide in mCRPC with prior progression on AA and docetaxel. MethodsThis double-blind, placebo-controlled, randomized phase 2 trial, recruited men ≥ 18 years with progressing mCRPC and performance status 0–2 from 15 UK centers. Randomized participants (1:1) received enzalutamide (160 mg orally, once daily) with capivasertib (400 mg)/ placebo orally, twice daily on an intermittent (4 days on, 3 days off) schedule. Primary endpoint was composite response rate (RR): RECIST 1.1 objective response, ≥ 50 % PSA decrease from baseline, or circulating tumor cell count conversion (from ≥ 5 at baseline to < 5 cells/7.5 mL). Subgroup analyses by PTENIHC status were pre-planned. ResultsOverall, 100 participants were randomized (50:50); 95 were evaluable for primary endpoint (47:48); median follow-up was 43 months. RR were 9/47 (19.1 %) enzalutamide/capivasertib and 9/48 (18.8 %) enzalutamide/placebo (absolute difference 0.4 % 90 %CI −12.8 to 13.6, p = 0.58), with similar results in the PTENIHC loss subgroup. Irrespective of treatment, OS was significantly worse for PTENIHC loss (10.1 months [95 %CI: 4.6–13.9] vs 14.8 months [95 %CI: 10.8–18]; p = 0.02). Most common treatment-emergent grade ≥ 3 adverse events for the combination were diarrhea (13 % vs 2 %) and fatigue (10 % vs 6 %). ConclusionsCombined capivasertib/enzalutamide was well tolerated but didn’t significantly improve outcomes from abiraterone pre-treated mCRPC.

Abstract CT288: Brightline-4: A phase 3 open-label, single-arm, multicenter study to assess the safety and efficacy of brigimadlin (BI 907828) treatment in patients with treatment-naïve or pretreated advanced dedifferentiated liposarcoma

Abstract Background Current treatment options for dedifferentiated liposarcoma (DDLPS) are associated with suboptimal efficacy and substantial toxicities. Purpose Brigimadlin (BI 907828) is a highly potent, orally available MDM2-p53 antagonist that binds to MDM2 and blocks its interaction with p53, thereby restoring p53 function, leading to cell cycle arrest and apoptosis in TP53 wild-type tumors. Brigimadlin has been evaluated in a phase 1a/1b study in patients with solid tumors (NCT03449381) and has shown encouraging preliminary efficacy in patients with DDLPS. Based on these data, brigimadlin is being investigated for the first-line treatment of advanced DDLPS in the randomized phase 2/3 Brightline-1 trial (NCT05218499). The Brightline-4 trial will generate additional safety and efficacy data in a broader DDLPS patient population. Experimental design Brightline-4 (NCT06058793) is an open-label, single-arm, global, multicenter phase 3 study that aims to assess the safety and efficacy of brigimadlin in patients with treatment-naïve or pretreated advanced DDLPS. Approximately 240 patients with treatment-naïve (Cohort A) or pre-treated (Cohort B) advanced DDLPS will be enrolled. All patients will receive brigimadlin 45 mg orally once every 3 weeks. Key inclusion criteria include: ≥18 years of age; locally advanced/metastatic, unresectable, histologically confirmed DDLPS; tumor MDM2 expression by immunohistochemistry or MDM2 amplification (via fluorescence in situ hybridization or next-generation sequencing); ≥1 measurable target lesion (RECIST v1.1); and ECOG PS 0/1. Key exclusion criteria include: prior treatment with an MDM2-p53 antagonist; known mutation in TP53; receiving treatment for brain metastases or leptomeningeal disease. Treatment will continue until disease progression, unacceptable toxicity, or withdrawal of consent. The primary endpoints are the occurrence of treatment-emergent adverse events (TEAEs) and grade ≥3 TEAEs according to NCI CTCAE v5. Secondary endpoints include objective response, progression-free survival, overall survival, duration of response, disease control and further assessment of safety. All analyses will be descriptive; no hypothesis testing is planned. Citation Format: Scott Schuetze, Girish Jayadeva, Michael Santoro. Brightline-4: A phase 3 open-label, single-arm, multicenter study to assess the safety and efficacy of brigimadlin (BI 907828) treatment in patients with treatment-naïve or pretreated advanced dedifferentiated liposarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT288.

177Lu]Lu-PSMA-617 as first-line systemic therapy in patients with metastatic castration-resistant prostate cancer: a real-world study.

The use of [177Lu]Lu-PSMA-617 radioligand therapy has become increasingly recognized as a viable therapeutic approach for patients in the advanced stages of metastatic castration-resistant prostate cancer (mCRPC). However, there is limited data regarding its effectiveness and safety in earlier lines. This study aims to present our institution's experience with [177Lu]Lu-PSMA-617 as a first-line systemic therapy for mCRPC. We collected and analyzed data from consecutive mCRPC patients who underwent first-line treatment with [177Lu]Lu-PSMA-617 at our center from 2015 to 2023. The various outcome measures included best prostate-specific antigen-response rate (PSA-RR) (proportion of patients achieving a ≥ 50% decline in PSA); objective radiographic response rate (ORR) (proportion of patients achieving complete or partial radiographic responses); radiographic progression-free survival (rPFS) (measured from treatment initiation until radiographic progression or death from any cause); overall survival (OS) (measured from treatment initiation until death from any cause); and adverse events. Forty treatment-naïve mCRPC patients with PSMA-positive disease on [68Ga]Ga-PSMA-11 PET/CT were included (median age: 68.5 years, range: 45-78; median PSA: 41 ng/mL, range: 1-3028). These patients received a median cumulative activity of 22.2 GBq (range: 5.55-44.4) [177Lu]Lu-PSMA-617 over 1-6 cycles at 8-12 week intervals. A ≥ 50% decline in PSA was observed in 25/40 (62.5%) patients (best PSA-RR). Radiographic responses were evaluated for thirty-eight patients, with thirteen showing partial responses (ORR 34.2%). Over a median follow-up of 36 months, the median rPFS was 12 months (95% confidence interval, CI: 9-15), and the median OS was 17 months (95% CI: 12-22). Treatment-emergent grade ≥ 3 anemia, leucopenia, and thrombocytopenia were noted in 4/40 (10%), 1/40 (2.5%), and 3/40 (7.5%) patients, respectively. The findings suggest that [177Lu]Lu-PSMA-617 is a safe and effective option as a first-line treatment in mCRPC. Further trials are needed to definitively establish its role as an upfront treatment modality in this setting.

Combined Lanreotide Autogel and Temozolomide Treatment of Progressive Pancreatic and Intestinal Neuroendocrine Tumors: The Phase II SONNET Study.

In advanced neuroendocrine tumors (NET), antiproliferative treatment options beyond somatostatin analogs remain limited. Temozolomide (TMZ) has shown efficacy in NET alone or combined with other drugs. SONNET (NCT02231762) was an open, multicenter, prospective, phase II study to evaluate lanreotide autogel 120 mg (LAN) plus TMZ in patients with progressive advanced/metastatic grade 1/2 gastroenteropancreatic (GEP) NET or of unknown primary. Patients could be enrolled at first-line or higher therapy line. The primary endpoint was disease control rate ([DCR], rate of stable disease [SD], partial [PR], and complete response [CR]) at 6 months of LAN and TMZ. Patients with nonfunctioning (NF) NET without progression at 6 months were randomized to 6-month LAN maintenance or watch and wait, patients with functioning (F)-NET with clinical benefit (PR, SD) continued on LAN. Fifty-seven patients were recruited. The majority of patients received the study drug at second or higher treatment line and had an NET G2. DCR at 6 months LAN and TMZ was 73.5%. After 6 months of further LAN maintenance, 54.5% of patients with F-NET and 71.4% with NF-NET had SD or PR vs 41.7% with NF-NET on observation only. LAN and TMZ were effective in all subgroups analyzed. At 12 months of follow-up, median progression-free survival was 11.1 months. Median serum chromogranin A decreased except in NF-NET on observation. O6-methylguanine DNA methyltransferase promoter methylation appeared to better reflect TMZ response than loss of gene expression. During combination therapy, the most frequent treatment-emergent adverse events grade 3/4 reported were nausea (14%), thrombocytopenia (12.3%), and neutropenia (8.8%). Four deaths were reported resulting from severe adverse events not considered related to study medication. LAN plus TMZ is a treatment option for patients with progressive GEP-NET with more aggressive biological profile showing a manageable safety profile.

Safety, Efficacy, and Pharmacokinetics of Combination SARS-CoV-2 Neutralizing Monoclonal Antibodies BMS-986414 (C135-LS) and BMS-986413 (C144-LS) Administered Subcutaneously in Non-Hospitalized Persons with COVID-19 in a Phase 2 Trial.

Outpatient COVID-19 monoclonal antibody (mAb) treatment via subcutaneous delivery, if effective, overcomes the logistical burdens of intravenous administration. ACTIV-2/A5401 was a randomized, masked placebo-controlled platform trial where participants with COVID-19 at low risk for progression were randomized 1:1 to subcutaneously administered BMS-986414 (C135-LS) 200 mg, plus BMS-986413 (C144-LS) 200 mg, (BMS mAbs), or placebo. Coprimary outcomes were time to symptom improvement through 28 days; nasopharyngeal SARS-CoV-2 RNA below the lower limit of quantification (LLoQ) on days 3, 7, or 14; and treatment-emergent grade 3 or higher adverse events (TEAEs) through 28 days. A total of 211 participants (105 BMS mAbs and 106 placebo) initiated study product. Time to symptom improvement favored the active therapy but was not significant (median 8 vs 10 days, P=0.19). There was no significant difference in the proportion with SARS-CoV-2 RNA <LLoQ at day 3 (risk ratio [RR] for BMS mAbs versus placebo: 1.03; 95%CI: 0.80, 1.32), at day 7 (RR: 1.04; 95%CI: 0.94, 1.15), or at day 14 (RR: 1.00; 95%CI: 0.90, 1.12). Fewer grade 3 TEAEs were reported for the BMS mAbs arm than placebo (RR: 0.58 [95%CI: 0.25, 1.32]). Through day 28, there were no deaths, and there were 4 hospitalizations in the BMS mAbs arm versus 3 in the placebo arm. Higher early plasma mAb concentrations were associated with more favorable outcomes. While safe, the BMS mAbs delivered subcutaneously were not effective at treating COVID-19 at low risk for progression. The lack of clinically significant activity may relate to the pharmacokinetics of subcutaneous administration of mAbs.

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.

Daratumumab, Pomalidomide and Dexamethasone (DPd) in Relapsed/ Refractory Light Chain Amyloidosis Previously Exposed to Daratumumab

Daratumumab, Pomalidomide and Dexamethasone (DPd) in Relapsed/ Refractory Light Chain Amyloidosis Previously Exposed to Daratumumab

Safety and efficacy of inhaled interferon-β1a (SNG001) in adults with mild-to-moderate COVID-19: a randomized, controlled, phase II trial

With the emergence of SARS-CoV-2 variants resistant to monoclonal antibody therapies and limited global access to therapeutics, the evaluation of novel therapeutics to prevent progression to severe COVID-19 remains a critical need. Safety, clinical and antiviral efficacy of inhaled interferon-β1a (SNG001) were evaluated in a phase II randomized controlled trial on the ACTIV-2/A5401 platform (ClinicalTrials.govNCT04518410). Adult outpatients with confirmed SARS-CoV-2 infection within 10 days of symptom onset were randomized and initiated either orally inhaled nebulized SNG001 given once daily for 14 days (n=110) or blinded pooled placebo (n=110) between February 10 and August 18,2021. The proportion of participants reporting premature treatment discontinuation was 9% among SNG001 and 13% among placebo participants. There were no differences between participants who received SNG001 or placebo in the primary outcomes of treatment emergent Grade 3 or higher adverse events (3.6% and 8.2%, respectively), time to symptom improvement (median 13 and 9 days, respectively), or proportion with unquantifiable nasopharyngeal SARS-CoV-2 RNA at days 3 (28% [26/93] vs. 39% [37/94], respectively), 7 (65% [60/93] vs. 66% [62/94]) and 14 (91% [86/95] vs. 91% [83/81]). There were fewer hospitalizations with SNG001 (n=1; 1%) compared with placebo (n=7; 6%), representing an 86% relative risk reduction (p=0.07). There were no deaths in either arm. In this trial, SNG001 was safe and associated with a non-statistically significant decrease in hospitalization for COVID-19 pneumonia. The ACTIV-2 platform study is funded by the NIH. Research reported in this publication was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health under Award Number UM1 AI068634, UM1 AI068636 and UM1 AI106701. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Targeting Hedgehog Signaling with Glasdegib in Patients with Refractory Sclerotic Chronic GVHD: A Report of Two Phase I/II Trials.

Sclerotic chronic GVHD (scGVHD) is characterized by progressive skin fibrosis and frequent refractoriness to available therapies. Aberrant activation of Hedgehog signaling in dermal fibroblasts has been implicated in scGVHD. Here, we report the results of two phase I/II studies (NCT03415867, GETH-TC; NCT04111497, FHD) that evaluated glasdegib, a smoothened antagonist, as a novel therapeutic agent in refractory scGVHD. Adult patients with active scGVHD after ≥1 (FHD) or ≥2 (GETH-TC) lines of therapy were enrolled. Primary endpoints were dose-limiting toxicity (DLT) and MTD in the GETH-TC trial, and safety and tolerability measures in the FHD trial. Glasdegib was administered once daily in 28-day cycles. Responses were scored per 2014 NIH cGVHD criteria. Correlative studies were performed to evaluate the role of fibroblast-independent immune mechanisms on clinical activity. Twenty (GETH-TC) and 15 (FHD) patients were recruited. Treatment-emergent grade (G) ≥2 adverse events (AE) in the GETH-TC trial included muscle cramps (85%), alopecia (50%), and dysgeusia (35%). Two patients experienced a DLT (G3 muscle cramps), and the MTD was established at 50 mg. G3 muscle cramps were the most frequently reported AE (33%) in the FHD trial. At 12-months, the skin/joint scGVHD overall response rate was 65% (all partial responses) in the GETH-TC trial and 47% (6 partial responses, 1 complete response) in the FHD cohort. No immune correlates of response were identified. Glasdegib demonstrated promising responses in patients with refractory scGVHD, but tolerability was limited by muscle cramping.

Safety and Efficacy of [177Lu]-PSMA-I&T Radioligand Therapy in Octogenarians with Metastatic Castration-Resistant Prostate Cancer: Report on 80 Patients over the Age of 80 Years.

177Lu-labeled prostate-specific membrane antigen (PSMA) radioligand therapy (RLT) is a new treatment option for metastatic castration-resistant prostate cancer (mCRPC). Its low toxicity profile favors use in elderly patients or in patients with critical comorbidities. The purpose of this analysis was to evaluate the efficacy and safety of [177Lu]-PSMA RLT in mCRPC patients at least 80 y old. Methods: Eighty mCRPC patients at least 80 y old underwent [177Lu]-PSMA-I&T RLT and were retrospectively selected. The patients were previously treated by androgen receptor-directed therapy, received taxane-based chemotherapy, or were chemotherapy-ineligible. The best prostate-specific antigen (PSA) response was calculated, as well as clinical progression-free survival (cPFS) and overall survival (OS). Toxicity data were acquired until 6 mo after the last treatment cycle. Results: Of 80 patients, 49 (61.3%) were chemotherapy-naïve and 16 (20%) had visceral metastases. The median number of previous mCRPC treatment regimens was 2. In total, 324 cycles (median, 4 cycles; range, 1-12) with a median cumulative activity of 23.8 GBq (interquartile range, 14.8-42.2) were applied. A PSA decline of 50% was achieved in 37 (46.3%) patients. Chemotherapy-naïve patients showed higher 50% PSA response rates than chemotherapy-pretreated patients (51.0% vs. 38.7%, respectively). Overall, median cPFS and OS were 8.7 and 16.1 mo, respectively. The median cPFS and OS of chemotherapy-naïve patients were significantly longer than those of chemotherapy-pretreated patients (10.5 vs. 6.5 mo and 20.7 vs. 11.8 mo, respectively, P < 0.05). A lower hemoglobin level and higher lactate dehydrogenase level at baseline were independent predictors of shorter cPFS and OS. Treatment-emergent grade 3 toxicities were anemia in 4 patients (5%), thrombocytopenia in 3 patients (3.8%), and renal impairment in 4 patients (5%). No nonhematologic grade 3 and no grade 4 toxicities were observed. The most frequent clinical side effects were grade 1-2 xerostomia, fatigue, and inappetence. Conclusion: [177Lu]-PSMA-I&T RLT in mCRPC patients at least 80 y old is safe and effective, comparable to previously published data on non-age-selected cohorts with a low rate of high-grade toxicities. Chemotherapy-naïve patients showed a better and longer response to therapy than taxane-pretreated patients. [177Lu]-PSMA RLT seems to be a meaningful treatment option for older patients.

A phase 1 study of the SYK inhibitor fostamatinib and weekly paclitaxel for recurrent platinum-resistant ovarian cancer.

5574 Background: Response to chemotherapy in patients (pts) with recurrent platinum-resistant ovarian cancer (PROC) is generally &lt; 15%. Spleen tyrosine kinase (SYK) is overexpressed in PROC and is a key mediator of paclitaxel resistance in ovarian cancer cells. Fostamatinib (Fos), an orally available inhibitor of SYK, is currently FDA approved for the treatment of idiopathic thrombocytopenic purpura. The active form of Fos (R406) was shown to synergistically enhance taxane-mediated cytotoxicity in preclinical ovarian cancer models. This phase 1 study aimed to identify the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of Fos when combined with standard weekly paclitaxel (wPac) for pts with PROC. Methods: Pts with PROC, defined as progression ≤6 months of last platinum, were eligible. A modified toxicity probability interval (mTPI) dose escalation design was used to determine the MTD/RP2D and response was assessed using RECISTv1.1 criteria. All pts received paclitaxel (wPac) 80mg/m2 intravenously on Days 1, 8, and 15, of a 28-day cycle. Fos was administered orally twice a day (BID) on a continuous schedule. Three dose levels (DL) were planned: DL1 - 100mg, DL2 - 150mg, and DL3 - 200mg. MTD was determined based on cycle 1 dose-limiting toxicities (DLTs) and responses were assessed every 2 cycles. A dose expansion cohort to further assess adverse events (AEs) and tolerability was performed. Results: 27 eligible pts, median age 62 years (range 35-79 years) with high-grade serous (n = 18), clear cell (n = 4), carcinosarcoma (n = 3), or other (n = 2) histology were treated at 3 centers. Twelve pts were treated in the dose escalation cohort (DL1 = 6, DL2 = 3, DL3 = 3). Common AEs at least possibly attributed to Fos, wPac, or both included diarrhea (70%), fatigue (52%), anemia (44%), neutropenia (33%), nausea (33%), hypertension (30%), and dysgeusia (30%). Treatment-emergent grade 3-4 AEs were neutropenia (37%), anemia (26%), and thromboembolic event (22%). During DL1, updated toxicity management guidelines not consistent with the original protocol were released and 2 of the 3 pts treated prior to the amendment were not considered evaluable for DLT. Thus 3 more pts were enrolled to DL1 after the amendment. Of the 10 pts evaluable for DLT in dose escalation, no DLTs were reported on any of the 3 DLs (DL1 = 4, DL2 = 3, DL3 = 3). DL3 was selected for dose expansion. One of 15 pts in the dose expansion cohort had a DLT (neutropenia) and one patient had a grade 5 infection. Of 18 pts treated at DL3, 7 (39%) had partial or complete response (95% CI: 17.3, 64.3%). Overall, 27 patients received a median of 3 cycles (range 0-10). Analysis of pharmacokinetic and correlative molecular studies of target expression are ongoing. Conclusions: The RP2D of Fos will be 200 mg orally BID when combined with wPac. AE profile of the combination was as expected and the combination demonstrated promising efficacy in pts with recurrent PROC. Clinical trial information: NCT03246074 .

A phase 2 evaluation of daratumumab-based induction therapy in patients with multiple myeloma with severe renal insufficiency.

8057 Background: Myeloma patients (pts) with renal insufficiency (RI) have inferior disease outcomes; up to 50% present with acute kidney injury (AKI). AKI results from light chain-induced cast nephropathy; physicochemical properties (self-association, aggregate formation) may determine severity. Daratumumab has extensive data in myeloma, reduces circulating light chains, preserves renal function in AL amyloidosis, and has non-renal clearance. We hypothesized early therapy with daratumumab and VRD normalize myeloma-induced AKI in a population rarely included in trials. Methods: We used a Simon’s two-stage design in newly diagnosed pts with severe AKI (CrCl &lt;30 mL/min) of 4 x 21-D cycles of daratumumab 16mg/kg IV QW x 3 (C1-3, C4D1 only), bortezomib 1.3 mg/m2 SQ D1, 4, 8, and 11, and dexamethasone 40mg (reduced to 20mg at C2 for ≥75 yrs.) D1-4 (C1 only, D1 only C2-4), 8, and 15, with add-on lenalidomide at C2 (25mg if CrCl ≥30 mL/min). Standard antiviral, antithrombotic, premedications were used. Eligibility criteria were broad (CrCl &lt;30 mL/min, PS 0-2, ANC&gt;1000/mm3, Hgb&gt;7 g/dL, plt&gt;75,000/mm3) with liberal dose reductions for generalizability. Primary objective: determine proportion with renal recovery (CrCl ≥50 mL/min) after 2 cycles; secondary objectives: best response (IMWG), renal function at end of treatment, dose density/tolerability, adverse events (AE), renal function change by estimates [Cockcroft-Gault (C-G), MDRD, 24-hour urine, CKD-EPI], and daratumumab PK. If ≥7 responses seen in the first 11 pts, 14 more would be accrued. These data are the planned analysis of the initial cohort. Results: Thirteen pts enrolled: 8 male, 7 white/6 black, median age 69 yr (46-82), 11 treated/evaluable for the primary endpoint. Median baseline CrCl 13.8 mL/min (4.9-20.2), median serum creatinine (SCr) 4.92 mg/dL (3.53-9.93). One withdrew consent, 1 was inevaluable (rapid disease progression and death). Seven achieved CrCl of ≥50 mL/min (median C3D1 CrCl 61 mL/min, 22-151) after 2 cycles, all had SCr improvement at C3D1. Lenalidomide dose was 25 mg on C2D1 in 9/11 pts. Median (range) dose density (delivered/planned): daratumumab 100% (40-100), bortezomib 100% (25-100), dexamethasone 80% (67-100), lenalidomide 100% (0-100). The overall response rate was 100%, ≥VGPR rate 82%. Best responses were CR (3), VGPR (6), PR (2). Treatment-emergent grade ¾ hematologic AEs: anemia (90.9%), lymphopenia (81.8%), thrombocytopenia (36.4%), neutropenia (9.1%). Conclusions: Early, aggressive therapy with a daratumumab-based induction regimen in myeloma pts with severe AKI improves renal function, with the majority achieving CrCl ≥50 mL/min after 2 cycles; all responded. AEs seen were consistent with prior experience with the 4-drug regimen. Per protocol, 14 additional patients will be accrued in the second stage. Clinical trial information: NCT04352205 .

Acute Toxicity of Hypofractionated and Conventionally Fractionated (Chemo)Radiotherapy Regimens for Bladder Cancer: An Exploratory Analysis from the RAIDER Trial

AimsAdding concurrent (chemo)therapy to radiotherapy improves outcomes for muscle-invasive bladder cancer patients. A recent meta-analysis showed superior invasive locoregional disease control for a hypofractionated 55 Gy in 20 fractions schedule compared with 64 Gy in 32 fractions. In the RAIDER clinical trial, patients undergoing 20 or 32 fractions of radical radiotherapy were randomised (1:1:2) to standard radiotherapy or to standard-dose or escalated-dose adaptive radiotherapy. Neoadjuvant chemotherapy and concomitant therapy were permitted. We report exploratory analyses of acute toxicity by concomitant therapy-fractionation schedule combination. Materials and methodsParticipants had unifocal bladder urothelial carcinoma staged T2-T4a N0 M0. Acute toxicity was assessed (Common Terminology Criteria for Adverse Events) weekly during radiotherapy and at 10 weeks after the start of treatment. Within each fractionation cohort, non-randomised comparisons of the proportion of patients reporting treatment emergent grade 2 or worse genitourinary, gastrointestinal or other adverse events at any point in the acute period were carried out using Fisher's exact tests. ResultsBetween September 2015 and April 2020, 345 (163 receiving 20 fractions; 182 receiving 32 fractions) patients were recruited from 46 centres. The median age was 73 years; 49% received neoadjuvant chemotherapy; 71% received concomitant therapy, with 5-fluorouracil/mitomycin C most commonly used: 44/114 (39%) receiving 20 fractions; 94/130 (72%) receiving 32 fractions. The acute grade 2+ gastrointestinal toxicity rate was higher in those receiving concomitant therapy compared with radiotherapy alone in the 20-fraction cohort [54/111 (49%) versus 7/49 (14%), P < 0.001] but not in the 32-fraction cohort (P = 0.355). Grade 2+ gastrointestinal toxicity was highest for gemcitabine, with evidence of significant differences across therapies in the 32-fraction cohort (P = 0.006), with a similar pattern but no significant differences in the 20-fraction cohort (P = 0.099). There was no evidence of differences in grade 2+ genitourinary toxicity between concomitant therapies in either the 20- or 32-fraction cohorts. ConclusionGrade 2+ acute adverse events are common. The toxicity profile varied by type of concomitant therapy; the gastrointestinal toxicity rate seemed to be higher in patients receiving gemcitabine.

Zolbetuximab plus mFOLFOX6 in patients with CLDN18.2-positive, HER2-negative, untreated, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma (SPOTLIGHT): a multicentre, randomised, double-blind, phase 3 trial

Zolbetuximab, a monoclonal antibody targeting claudin-18 isoform 2 (CLDN18.2), has shown efficacy in patients with CLDN18.2-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma. We report the results of the SPOTLIGHT trial, which investigated the efficacy and safety of first-line zolbetuximab plus mFOLFOX6 (modified folinic acid [or levofolinate], fluorouracil, and oxaliplatin regimen) versus placebo plus mFOLFOX6 in patients with CLDN18.2-positive, HER2-negative, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma. SPOTLIGHT is a global, randomised, placebo-controlled, double-blind, phase 3 trial that enrolled patients from 215 centres in 20 countries. Eligible patients were aged 18 years or older with CLDN18.2-positive (defined as ≥75% of tumour cells showing moderate-to-strong membranous CLDN18 staining), HER2-negative (based on local or central evaluation), previously untreated, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma, with radiologically evaluable disease (measurable or non-measurable) according to Response Evaluation Criteria in Solid Tumors version 1.1; an Eastern Cooperative Oncology Group performance status score of 0 or 1; and adequate organ function. Patients were randomly assigned (1:1) via interactive response technology and stratified according to region, number of organs with metastases, and previous gastrectomy. Patients received zolbetuximab (800 mg/m2 loading dose followed by 600 mg/m2 every 3 weeks) plus mFOLFOX6 (every 2 weeks) or placebo plus mFOLFOX6. The primary endpoint was progression-free survival assessed by independent review committee in all randomly assigned patients. Safety was assessed in all treated patients. The study is registered with ClinicalTrials.gov, NCT03504397, and is closed to new participants. Between June 21, 2018, and April 1, 2022, 565 patients were randomly assigned to receive either zolbetuximab plus mFOLFOX6 (283 patients; the zolbetuximab group) or placebo plus mFOLFOX6 (282 patients; the placebo group). At least one dose of treatment was administered to 279 (99%) of 283 patients in the zolbetuximab group and 278 (99%) of 282 patients in the placebo group. In the zolbetuximab group, 176 (62%) patients were male and 107 (38%) were female. In the placebo group, 175 (62%) patients were male and 107 (38%) were female. The median follow-up duration for progression-free survival was 12·94 months in the zolbetuximab group versus 12·65 months in the placebo group. Zolbetuximab treatment showed a significant reduction in the risk of disease progression or death compared with placebo (hazard ratio [HR] 0·75, 95% CI 0·60-0·94; p=0·0066). The median progression-free survival was 10·61 months (95% CI 8·90-12·48) in the zolbetuximab group versus 8·67 months (8·21-10·28) in the placebo group. Zolbetuximab treatment also showed a significant reduction in the risk of death versus placebo (HR 0·75, 95% CI 0·60-0·94; p=0·0053). Treatment-emergent grade 3 or worse adverse events occurred in 242 (87%) of 279 patients in the zolbetuximab group versus 216 (78%) of 278 patients in the placebo group. The most common grade 3 or worse adverse events were nausea, vomiting, and decreased appetite. Treatment-related deaths occurred in five (2%) patients in the zolbetuximab group versus four (1%) patients in the placebo group. No new safety signals were identified. Targeting CLDN18.2 with zolbetuximab significantly prolonged progression-free survival and overall survival when combined with mFOLFOX6 versus placebo plus mFOLFOX6 in patients with CLDN18.2-positive, HER2-negative, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma. Zolbetuximab plus mFOLFOX6 might represent a new first-line treatment in these patients. Astellas Pharma, Inc.

A four-drug standardized short regimen for highly resistant TB in South-West Nigeria.

Patients with TB resistant to rifampicin (Rr-TB), and those with additional resistance to fluoroquinolones (pre-XDR-TB), should be treated with bedaquiline-pretomanid-linezolid-moxifloxacin and bedaquiline-pretomanid-linezolid, respectively. However, pretomanid is not yet widely available. This is a pragmatic prospective single-arm study investigating the efficacy and safety of 9 mo of bedaquiline-delamanid-linezolid-clofazimine in patients with pre-XDR-TB or Rr-TB unresponsive to Rr-TB treatment in Nigeria. From January 2020 to June 2022, 14 of 20 patients (70%) successfully completed treatment, five died and one was lost-to-follow-up. No one experienced a treatment-emergent grade three/four event. Treatment success was higher compared with global pre-XDR-TB treatment outcomes. While pretomanid is unavailable, highly resistant TB can be treated with bedaquiline-delamanid-linezolid-clofazimine.

Targeting Hedgehog Signaling with Glasdegib in Patients with Refractory Sclerotic Chronic Graft vs. Host Disease: A Report of Two Phase I/II Trials

Introduction Sclerotic chronic graft vs. host disease (scGVHD) is characterized by progressive skin fibrosis that often causes limited mobility and poor quality of life. Aberrant activation of hedgehog signaling leading to the differentiation of dermal fibroblasts into collagen-releasing myofibroblasts has been implicated in scGVHD. Targeted inhibition with hedgehog pathway inhibitors ameliorate fibrosis in experimental models. Our objective was to determine the safety and efficacy of glasdegib, an oral antagonist of the hedgehog signalling transducer Smoothened (SMO) in adult patients (pts) with refractory scGVHD. Methods Two independent, single-arm, open-label, phase I/II investigator-initiated studies [NCT03415867, Spanish Transplantation and Cellular Therapy Cooperative Group (GETH); NCT04111497, Fred Hutchinson Cancer Center/Huntsman Cancer Institute/Duke University Medical Center (FHD)] were performed. Adults with active scGVHD after ≥1 (FHD) or ≥2 (GETH) lines of prior therapy were enrolled. The GETH trial followed a 3+3 dose-finding strategy, whereas the FHD trial employed a fixed-dose design. Primary endpoints were dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) in the GETH trial, and safety and tolerability in the FHD trial. Secondary endpoints included efficacy, patient-reported outcomes and biological correlates of response. Glasdegib was administered once daily in continuous 28-day cycles. Individual organs were scored per 2014 NIH cGVHD criteria. A scGVHD partial response (PR) was defined as skin and/or joints score improvement (≥1 point for body surface area [BSA], skin features or joints/fascia scores; ≥2 points for skin/joints tightening or total P-ROM scores) in the absence of worsening in those scores or an increase ≥2 points in the global severity score. Data cut-off was at 12 months from time of glasdegib initiation. Results Twenty (GETH) and 15 (FHD) pts were enrolled who received a median of 4 (range 2-10) and 4 (1-16) prior lines of therapy. The median age was 47 years (range 27-73) and 64 (33-74) in the GETH and FHD studies, respectively. In the GETH trial, 3 pts were included in cohort 1 (50 mg), 3 in cohort 2 (100 mg) and 16 in the expansion cohort (50 mg). All pts in the FHD trial received glasdegib at an initial dose of 50 mg. Frequent treatment-emergent grade (G) ≥2 adverse events (AEs) in the GETH trial included muscle cramps (85%), alopecia (50%) and dysgeusia (35%). Two pts in cohort 2 experienced a DLT (G3 muscle cramps) that resulted in establishment of the MTD at 50 mg. Similarly, G3 muscle cramps were the most frequently reported adverse event (AE) occurring in 33% of pts in the FHD trial. In the FHD study, a pre-specified trial stopping rule was triggered by the emergence of G3 muscle cramps AEs in 5 pts. In the GETH trial, glasdegib dose reductions were undertaken in 10 pts, and 8 pts stopped glasdegib before completion of 12 cycles of therapy. Ten pts remained on treatment beyond 12 months. In the FHD trial, the glasdegib dose was reduced in 5 pts; 12 pts stopped glasdegib before 12 cycles. Two pts remained on treatment for longer than 12 months and one pt remains on glasdegib at 10 months. At the 12-month data cut-off, 9 (45%) pts in the GETH trial achieved a skin BSA score and/or sclerotic features score PR, and 9 (45%) pts had obtained a joints/fascia score response (6 PRs, 3 complete responses). Corresponding findings in the FHD trial were 4 pts (27%; 3 PRs, 1 CR) and 3 pts (20%; 2 PRs, 1 CR). An improvement ≥2 points in the total P-ROM score was observed in 11 (55%) pts in the GETH study and 4 (27%) pts in the FHD study, Additionally, an improvement ≥2 points in the 0-10 skin and/or joint tightening severity scale was reported in 13 (65%) and 4 (31%; 2 pts with missing data) pts in the GETH and FHD trials, respectively. Overall, 13 (65%) pts obtained a scGVHD PR in the GETH trial, with a median time of 2.4 months to response. Likewise, 7 (47%) pts had a scGVHD PR in the FHD group, with a median time of 0.9 months to response. Preliminary correlative studies did not show changes in the distribution of T-cell subpopulations or TCR diversity in the GETH trial. Conclusions Glasdegib demonstrated high rates of clinical activity in heavily pretreated pts with scGVHD, but tolerability was hampered by the emergence of treatment-related muscle cramps. Yet, selected pts derived a sustained benefit from treatment in the absence of limiting toxicities. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Siremadlin Monotherapy and in Combination with Donor Lymphocyte Infusion for Patients with Acute Myeloid Leukemia Post Allogeneic Stem Cell Transplantation Who Are in Complete Remission but at High Risk for Relapse

Background: Relapse post allogeneic stem cell transplantation (SCT) remains the main cause of treatment failure (~40%) for patients (pts) with acute myeloid leukemia (AML). Many pts who ultimately relapse post SCT do so within the first year post transplant, and earlier relapse is associated with poorer survival. Therapeutics that prevent early relapse for these pts are urgently needed. Early cellular or pharmacologic intervention or maintenance strategies that enhance the graft-versus-leukemia (GvL) effect after SCT are of renewed interest as they have the potential to reduce relapse risk post SCT. Siremadlin (HDM201) is a novel investigational MDM2 inhibitor with single-agent, anti-AML activity. MDM2 inhibitors, including siremadlin, possess potent immunomodulatory effects in murine solid tumor and AML models. MDM2 inhibition has been shown to synergize with the allogeneic immune response, increase the vulnerability of AML cells to allogeneic donor T cells, and promote the cytotoxicity and longevity of allogeneic donor T cells in murine models. As such, the post-SCT setting is ideal for investigating the immunomodulatory effects of MDM2 inhibition on enhancing the GvL effect (Ho et al. Blood. 2022). Here we describe the design of a Phase Ib/II, open-label study of siremadlin as monotherapy and in combination with donor lymphocyte infusion (DLI) in pts with AML post SCT who are in complete remission (CR) but at high risk for relapse based on the presence of pre-SCT risk factors (NCT05447663). Study Design: The trial is not yet recruiting but aims to enroll ~38 adult pts with AML who underwent first SCT and are currently between Day 60-120 post SCT. Prior to a patient's SCT, they must have a risk factor that puts them at high risk for relapse, including AML in first CR with adverse risk genetics per 2017 European LeukemiaNet risk stratification, therapy-related AML, or secondary AML; or AML in second or greater CR. The SCT must be from an 8/8 human leukocyte antigen (HLA) matched related or unrelated donor at HLA-A, -B, -C, -DRB1 loci using unmanipulated/T-cell replete bone marrow or peripheral blood stem cells as a stem cell source. Post SCT, pts must have achieved CR or CR with incomplete hematologic recovery (CRi) with no evidence of hematologic relapse. Exclusion criteria include prior exposure to an MDM inhibitor, active graft-vs-host disease (GvHD), past history of grade ≥III acute GvHD (aGvHD) or moderate/severe chronic GvHD (cGVHD), recipient of SCT from a haploidentical family donor or cord blood transplant, and prior systemic AML-directed treatments given at any time after SCT (including DLI). This study contains 2 parts, Part 1 is a dose confirmation of siremadlin monotherapy and will enroll ~12 pts. Siremadlin will be tested at a maximum of 3 dose levels with a starting dose of 30 mg/d on Days 1-5 of a 28-day cycle, dose level +1 at 40 mg/d and dose level -1 at 20 mg/d. The safety and tolerability of these dose levels will be assessed to determine the siremadlin recommended dose (RD) for Part 2. Pts in Part 1 of the study will receive siremadlin monotherapy for the entire duration of the treatment and will not receive DLI. Subsequently, ~26 pts will be enrolled in Part 2 and proceed through a priming phase with siremadlin monotherapy at the RD, followed by a combination phase of siremadlin + DLI, and subsequently a maintenance phase with siremadlin monotherapy (Figure). Primary safety endpoints of the study are incidence of dose-limiting toxicities (DLTs) in Part 1 and time to DLT in Part 2. The primary efficacy endpoint is the proportion of pts in Part 2 who are alive and maintained CR/CRi without hematologic relapse ≥6 months after the start of study treatment. Secondary endpoints include number of pts in Part 1 who are alive and maintained CR/CRi without hematologic relapse ≥6 months after the start of study treatment at the RD for Part 2, time to first documented hematologic relapse or death, incidence of relapse at 1 year and 2 years post study treatment, safety, GvHD-free/relapse-free survival, incidence of and time to treatment-emergent grade ≥III aGvHD or moderate/severe cGvHD, and pharmacokinetics. Conclusions: This Phase Ib/II study investigates siremadlin monotherapy and siremadlin in combination with DLI in pts with AML in remission but at high risk of relapse post SCT. The study will evaluate the unique immunomodulatory potential of siremadlin to reduce risk of relapse in this population with high unmet need. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal