Oral Selective Inhibitor Research Articles

Symptom management in isocitrate dehydrogenase mutant glioma

Abstract According to the 2021 World Health Organization classification of CNS tumors, gliomas harboring a mutation in isocitrate dehydrogenase (mIDH) are considered a distinct disease entity, typically presenting in adult patients before the age of 50 years. Given their multiyear survival, patients with mIDH glioma are affected by tumor and treatment-related symptoms that can have a large impact on the daily life of both patients and their caregivers for an extended period of time. Selective oral inhibitors of mIDH enzymes have recently joined existing anticancer treatments, including resection, radiotherapy, and chemotherapy, as an additional targeted treatment modality. With new treatments that improve progression-free and possibly overall survival, preventing and addressing daily symptoms becomes even more clinically relevant. In this review we discuss the management of the most prevalent symptoms, including tumor-related epilepsy, cognitive dysfunction, mood disorders, and fatigue, in patients with mIDH glioma, and issues regarding patient’s health-related quality of life and caregiver needs in the era of mIDH inhibitors. We provide recommendations for practicing healthcare professionals caring for patients who are eligible for treatment with mIDH inhibitors.

Outcomes of Down-Titration in Patients with Severe Scalp Alopecia Areata Initially Treated with Baricitinib 4-mg: Week 152 data from BRAVE-AA2

BackgroundBaricitinib, an oral selective Janus kinase inhibitor, is approved to treat adults with severe alopecia areata (AA). ObjectiveTo report the Week 152 efficacy results from the Phase 3 trial BRAVE-AA2 down-titration sub-study. MethodsBRAVE-AA2 enrolled 546 adults with severe AA (Severity of Alopecia Tool [SALT] score ≥50). Baricitinib 4-mg treated patients achieving a clinical response (SALT score ≤20) at Week 52 were rerandomized 1:1 to stay on 4-mg or down-titrate to 2-mg. Last observation carried forward was used to impute missing or censored data. ResultsAt Week 52, 86/234 (36.8%) baricitinib 4-mg treated patients were eligible for down-titration; 44 remained on 4-mg while 42 down-titrated to 2-mg. At Week 152, 39/44 (88.6%) 4-mg treated patients had maintained clinical response, compared to 24/41 (58.5%) down-titrated patients. Among down-titrated patients, loss of treatment benefit was less frequent in those with sustained response and SALT score ≤5 at Week 52. LimitationsMethod and timing of down-titration were pre-specified in the protocol based on Week 52 responder status and not on other clinical factors. ConclusionMore than half of down-titrated patients maintained response. Sustained treatment response and/or near-total regrowth may be associated with a greater likelihood of response maintenance after down-titration.

Effectiveness and safety of upadacitinib in acute severe ulcerative colitis patients from single Chinese IBD Center: a monocentric study

Upadacitinib is an oral new selective JAK1 inhibitor that has been approved for treating adult patients with moderately to severely active ulcerative colitis. However, a growing number of studies are needed on the effectiveness of upadacitinib in the treatment of acute severe ulcerative colitis. This study was mainly aimed to describe the clinical and endoscopic effectiveness of upadacitinib 45 mg in Chinese acute severe ulcerative colitis patients following eight weeks of treatment. In this study, we examined all patients with acute severe ulcerative colitis from Xijing IBD Center, Xi’an, China, with acute severe ulcerative colitis. All patients were initially given oral upadacitinib 45 mg. Clinical indicators, C-reactive protein, and erythrocyte sedimentation rates were collected. Clinical response and clinical remission were assessed using modified Mayo. Endoscopic evaluation was performed carried out using the Mayo Endoscopic Score and Ulcerative colitis endoscopic index of severity score. A total of 14 patients who received upadacitinib were included in the study period. All patients exhibited a clinical response to 45 mg upadacitinib initially. All patients completed the 8-week induction. The clinical remission rate was 28.6% after eight weeks. Two patients revealed endoscopic remission at 14.3%. The pathology improved in 50.0% of patients. The 8-week surgical resection rate was 7.1%, with the 16-week surgical resection rate being 14.3%. Adverse events included herpes simplex virus infection and increased thrombin time. The results of our study support the short-term effectiveness and safety of upadacitinib in acute severe ulcerative colitis, providing new choices for patients’ treatment. However, more extended investigation needs to be performed on the long-term effectiveness and safety.

Ziftomenib in relapsed or refractory acute myeloid leukaemia (KOMET-001): a multicentre, open-label, multi-cohort, phase 1 trial

Ziftomenib (KO-539) is an oral selective menin inhibitor with known preclinical activity in menin-dependent acute myeloid leukaemia models. The primary objective of this study was to determine the recommended phase 2 dose in patients with relapsed or refractory acute myeloid leukaemia based on safety, pharmacokinetics, pharmacodynamics, and preliminary activity. KOMET-001 is a multicentre, open-label, multi-cohort, phase 1/2 clinical trial of ziftomenib in adults with relapsed or refractory acute myeloid leukaemia. Results of the phase 1 study, conducted at 22 hospitals in France, Italy, Spain, and the USA, are presented here and comprise the dose-escalation (phase 1a) and dose-validation and expansion (phase 1b) phases. Eligible patients were aged 18 years or older, had relapsed or refractory acute myeloid leukaemia, and had an Eastern Cooperative Oncology Group performance status of 2 or less. For phase 1a, patients (all molecular subtypes) received ziftomenib (50-1000 mg) orally once daily in 28-day cycles. For phase 1b, patients with NPM1 mutations or with KMT2A rearrangements were randomly assigned (1:1) using third-party interactive response technology to two parallel dose cohorts (200 mg and 600 mg ziftomenib). Primary endpoints were maximum tolerated dose or recommended phase 2 dose in phase 1a, and safety, remission rates, and pharmacokinetics supporting recommended phase 2 dose determination in phase 1b. Analyses were performed in all patients who received at least one dose of ziftomenib (modified intention-to-treat population). Phase 1a/1b is complete. This trial is registered with ClinicalTrials.gov, NCT04067336, and the EU Clinical Trials register, EudraCT 2019-001545-41. From Sept 12, 2019, to Aug 19, 2022, 83 patients received 50-1000 mg ziftomenib (39 [47%] were male and 44 [53%] were female). Median follow-up was 22·3 months (IQR 15·4-30·2). Of 83 patients, the most common grade 3 or worse treatment-emergent adverse events were anaemia (20 [24%]), febrile neutropenia (18 [22%]), pneumonia (16 [19%]), differentiation syndrome (12 [15%]), thrombocytopenia (11 [13%]), and sepsis (ten [12%]). Overall, 68 of 83 patients had serious adverse events, with two reported treatment-related deaths (one differentiation syndrome and one cardiac arrest). Differentiation syndrome rate and severity influenced the decision to halt enrolment of patients with KMT2A rearrangements. In Phase 1b, no responses were reported in patients treated at the 200 mg dose level. At the recommended phase 2 dose of 600 mg, nine (25%) of 36 patients with KMT2A rearrangement or NPM1 mutation had complete remission or complete remission with partial haematologic recovery. Seven (35%) of 20 patients with NPM1 mutation treated at the recommended phase 2 dose had a complete remission. Ziftomenib showed promising clinical activity with manageable toxicity in heavily pretreated patients with relapsed or refractory acute myeloid leukaemia. Phase 2 assessment of ziftomenib combination therapy in the upfront and relapsed or refractory setting is ongoing. Kura Oncology.

Discovery of TYRA-300: First Oral Selective FGFR3 Inhibitor for the Treatment of Urothelial Cancers and Achondroplasia.

Activating FGFR3 alterations have been identified in up to 15-20% of muscle-invasive bladder cancer and metastatic urothelial carcinoma (mUC), and as high as 80% in nonmuscle invasive bladder cancers. FGFR3 germline mutations have also been associated with a variety of skeletal dysplasias. Achondroplasia, the most common form of dwarfism in humans, results from a G380R mutation in FGFR3. The pan-FGFR inhibitor erdafitinib was approved for the treatment of mUC with FGFR3 alterations but is limited due to FGFR isoform off-target toxicities and the development of on-target gatekeeper resistance mutations. TYRA-300 (22) was conceived using a structure-based approach as a potent FGFR3-selective inhibitor to avoid the toxicities associated with inhibition of FGFR1, FGFR2, and FGFR4, and to be agnostic for the FGFR3 gatekeeper mutations. TYRA-300 is being evaluated in a Phase 1 clinical trial in urothelial cancers and solid tumors, with intention to initiate Phase 2 studies in urothelial cancers and achondroplasia.

Abstract P440: Discovery of clinical candidate GSC002219, a highly selective oral CYP11B2 inhibitor for hypertension

Background: Aldosterone is an important mediator of hypertension and its aberration could contribute to heart and kidney diseases. Aldosterone synthase inhibitors (ASI) attenuate the production of aldosterone directly and have been proposed as an alternative to mineralocorticoid receptor antagonists (MRA) for treatment of resistant hypertension and chronic renal disease. GSC002219 is a potent inhibitor of aldosterone synthase (CYP11B2) with high selectivity over the closely related enzyme CYP11B1. The aim of the study was to evaluate the effect of GSC002219 on aldosterone and blood pressure. Methods: The inhibitory effect of GSC002219 against CYP11B2 and CYP11B1 proteins was assessed in human renal leiomyoblastoma cells expressing recombinant human / cynomolgus CYP11B1or CYP11B2 enzymes, respectively. GSC002219 was further evaluated in Synacthen (ACTH) challenged cynomolgus monkey model for its effects against various related key biomarkers including cortisol, aldosterone and precursors. The effects of GSC002219 on systolic blood pressure (SBP) and diastolic blood pressure (DBP) were evaluated in stroke-prone spontaneously hypertensive rat (SHRSP) model. Results: GSC002219 potently inhibits CYP11B2 with an IC 50 of 27nM, while maintains a >150-fold selectivity over CYP11B1. In ACTH challenged cynomolgus monkey model, single oral doses of GSC002219 at 0.03 mg/kg and 0.1 mg/kg could suppress aldosterone production to 80% and 93%, respectively, comparing to vehicle-treated animals without any effect towards cortisol levels. In the rat SHRSP hypertension model, GSC002219 could effectively lower both SBP and DBP. GSC002219 has an excellent in vitro ADME and toxicology profile as well as a balanced physicochemical property. In 14-day rat and monkey toxicology studies, GSC002219 displayed good tolerance, excellent PK profile and a great safety window (>100 fold). Conclusions: Taken together, GSC002219 is a safe and potent inhibitor of CYP11B2 and efficacious in various disease models of hypertension. GSC002219 is under IND-enabling study and may enter the clinical development early 2025.

644 - Effectiveness and safety of upadacitinib in adolescent and adult patients with atopic dermatitis: an interim analysis of week 20-32 data from a real-world multicenter retrospective review

Abstract Introduction While clinical trial data demonstrates the efficacy and safety of upadacitinib (UPA), a selective oral Janus kinase inhibitor (JAKi) for atopic dermatitis (AD), there is still a lack of real-world evidence. Objectives Our study evaluated the real-world effectiveness and safety of UPA for AD at weeks 20-32. Methods We conducted a multicenter retrospective review at three practices in Canada. Effectiveness endpoints evaluated at weeks 20-32 included Investigator Global Assessment (IGA) score of clear or almost clear (IGA 0/1) as well as improvements in Eczema Area and Severity Index (EASI), body surface area (BSA), IGAxBSA, and Dermatology Life Quality Index (DLQI)/Children’s DLQI (CDLQI). Safety was ­determined via incidence of treatment-related adverse events (AEs). Results A total of 131 patients were included in the analysis. Mean age was 44.3 ± 17.5 (range: 12-78) years; 53.4% (70/131) were female. UPA doses were 15 mg (43.5%, 57/131) or 30 mg (56.5%, 74/131) once daily. Previous treatments included: topical therapy (100%, 131/131), phototherapy (29%, 38/131), systemic non-biologic therapy (75.6%, 99/131), and systemic biologic/JAKi therapy (38.9%, 51/131). At weeks 20-32: 85.5% (112/131) of patients achieved IGA 0/1; 84.3% (59/70), 75.7% (53/70), and 62.9% (44/70) of patients achieved EASI improvements of 75% (EASI75), 90% (EASI90), and 100% (EASI100), respectively; mean EASI was reduced from 12.7 to 0.7 (p=0.0001; mean EASI improvement = 88.8%); 94.3% (66/70), 92.9% (65/70), 90% (63/70), and 77.1% (54/70) of patients achieved absolute EASI scores <7, 5, <3, and <1, respectively; mean BSA was reduced from 16.4% to 0.9% (p=0.0001; mean BSA improvement=92.5%); mean IGAxBSA was reduced from 53.5 to 1.6 (p=0.0001; mean IGAxBSA improvement=95.7%); and mean DLQI/CDLQI was reduced from 13 to 1.2 (p=0.0001; mean DLQI/CDLQI improvement=90.5%), with 84.6% (55/65) of patients achieving DLQI/CDLQI 0/1. UPA monotherapy was utilized in 38.9% (51/131) of cases. Common concomitant therapies included topical corticosteroids (56.5%, 74/131), systemic corticosteroids (5.3%, 7/131), and topical calcineurin inhibitors (3.8%, 5/131). Frequent AEs included: acne (18.3%, 24/131), hypertriglyceridemia (18.3%, 24/131), elevated creatine phosphokinase (12.2%, 16/131), herpes simplex (5.3%, 7/131), and transaminitis (5.3%, 7/131). Five patients (3.8%) discontinued UPA due to treatment-related AEs (myalgia/arthralgia [n=2]; gastrointestinal discomfort [n=1]; venous thromboembolism [n=1]; folliculitis [n=1]). No serious infections, tuberculosis, major adverse cardiovascular events, gastrointestinal perforation, or malignancy were observed in 67.4 patient-years of safety follow-up. Conclusions Our real-world study shows that UPA is an effective and safe therapy for AD, with high levels of skin clearance and a favorable safety profile between weeks 20-32. These results indicate that UPA may perform better in the real-world versus clinical trial setting, as compared to the Heads Up and Rising Up studies at week 24, specifically for IGA 0/1 and EASI75/EASI90/EASI100 achievement. This may be explained by less severe baseline disease severity in our study. Limitations of this study include its sample size and retrospective nature.

Phase IB Study of Oral Selinexor in Combination with Rituximab and Platinum Chemotherapy in Patients with Relapsed/Refractory B-Cell Lymphoma-Final Analysis.

Selinexor is an oral selective inhibitor of exportine-1 (XPO1) with efficacy as a single agent in heavily pretreated diffuse large B-cell lymphoma (DLBCL). We conducted a study investigating the combination of selinexor with rituximab and platinum-based chemotherapy in B-cell lymphoma. We conducted a phase 1b, dose-escalation, and expansion trial, which enrolled patients with relapsed or refractory B-cell non-Hodgkin lymphoma. Patients received oral selinexor according to a 3 + 3 design in combination with rituximab and dexamethasone, high-dose cytarabine, oxaliplatine (DHAOX) or gemcitabine, dexamethasone, and cisplatin (GDP) chemotherapy. A total of 39 patients were enrolled, 27 during the escalation phase and 12 during the expansion phase. Most patients had diffuse large B-cell lymphoma (DLBCL; 77%). Group R-DHAOX was prematurely closed to inclusion due to a recommendation from the French drug agency, independent of this trial. A recommended phase 2 dose (RP2D) of selinexor in association with R-GPD was established at 40 mg on days 1, 8, and 15 of each 21-day cycle. In a population of 18 patients treated at this dose of selinexor, the most frequent grade 3-4 adverse events were hematological. With this regimen, seven obtained a complete metabolic response and five a partial response. The median PFS was 5.8 months. Among the patients with R/R B-cell lymphoma, selinexor at a weekly dose of 40 mg with R-GDP is feasible for outpatients, with a generally acceptable safety profile.

Efficacy and safety of deuruxolitinib, an oral selective Janus kinase inhibitor, in adults with alopecia areata: Results from the Phase 3 randomized, controlled trial (THRIVE-AA1)

BackgroundAlopecia areata (AA) is a hair loss disorder that can seriously impact quality of life. Janus kinase (JAK) inhibitors, including deuruxolitinib, have previously demonstrated significant hair regrowth in AA. ObjectiveThe Phase 3 THRIVE-AA1 randomized, double-blinded, placebo-controlled trial (NCT04518995) evaluated safety and efficacy of the oral JAK1/JAK2 inhibitor deuruxolitinib in adult patients with AA. MethodsPatients aged 18–65 years with ≥50% hair loss were randomized to deuruxolitinib 8 mg BID, deuruxolitinib 12 mg BID, or placebo for 24 weeks. The primary endpoint was percentage of patients achieving Severity of Alopecia Tool (SALT) score ≤20. A key secondary endpoint was percentage of satisfaction of hair patient-reported outcome (SPRO) responders. ResultsSignificantly higher proportions of patients taking deuruxolitinib met the primary endpoint (8 mg 29.6%; 12 mg 41.5% versus placebo 0.8%). Both deuruxolitinib doses achieved significant improvements in all secondary endpoints versus placebo, including SPRO (8 mg 42.1%; 12 mg 53.0% versus placebo 4.7%). Most treatment-emergent adverse events were mild or moderate, consistent with other oral JAK inhibitors. LimitationsFurther studies are required to understand longer-term safety, efficacy, and impact of treatment cessation. ConclusionBoth doses of deuruxolitinib were effective for hair regrowth. Patient satisfaction aligned with hair growth.

NFS-27. SELUMETINIB FOR SYMPTOMATIC, INOPERABLE PLEXIFORM NEUROFIBROMAS IN NEUROFIBROMATOSIS TYPE 1: A SINGLE-INSTITUTION EXPERIENCE

Abstract BACKGROUND Half of patients with Neurofibromatosis type 1 (NF1) develop plexiform neurofibromas (PNs). PNs may grow during childhood causing significant complications, including pain, functional impairment, and disfigurement. Treatment options are limited, given their tendency to regrow following surgery and their propensity to transform into malignant tumors following radiation. Selumetinib is an oral selective inhibitor of RAS-mitogen activated protein kinase (MAPK) 1 and 2, which has shown efficacy for tumor shrinkage/ stabilisation and symptom improvement. METHODS Single-institution retrospective review of patients with NF1 treated with selumetinib for symptomatic PNs between 2020 and 2023. Clinical data were abstracted from medical records. Treatment consisted of selumetinib 25 mg/m2 BID. Patient follow-up included monthly complete physical examination, evaluation of treatment adherence, blood analysis, echocardiogram, ophthalmologic assessment every 3 months, and MRI every 6 months. Response evaluation criteria in solid tumors (RECIST) was used for assessment. RESULTS Ten patients were treated with selumetinib during the period indicated. Mean age 13.9 years (range 7-21). Predominant target locations were head and neck (60%), and abdomen-pelvis (30%). The most important comorbidities were disfigurement (50%) and pain (50%). The mean follow-up time was 519 days (range 45–1460). None of the patients presented grade 3-4 toxicities; all of them had associated grade 1-2 skin toxicity. None presented cardiac or ophthalmologic alterations. All the patients with pain had sustained clinical improvement in the first 35–60 days of treatment. At one year of treatment 6/8 patients showed stable disease and 2/8 partial response on MRI. In one patient, treatment was discontinued after 270 days (lack of clear benefit).Another patient has not reached one year of therapy yet. CONCLUSIONS In this study we expose that selumetinib for symptomatic, inoperable plexiform neurofibromas in NF1 was associated with clinical and radiological response. Our study also confirms the safety and good tolerance of this drug.

Phase II study of vemurafenib in children and young adults with tumors harboring BRAF V600 mutations: NCI-COG pediatric MATCH trial (APEC1621) Arm G.

This is a phase II subprotocol of the NCI-COG Pediatric MATCH study evaluating vemurafenib, a selective oral inhibitor of BRAF V600 mutated kinase, in patients with relapsed or refractory solid tumors harboring BRAF V600 mutations. Patients received vemurafenib at 550 mg/m2 (maximum 960 mg/dose) orally twice daily for 28-day cycles until progression or intolerable toxicity. The primary aim was to determine the objective response rate and secondary objectives included estimating progression-free survival and assessing the tolerability of vemurafenib. Twenty-two patients matched to the subprotocol and 4 patients (18%) enrolled. Primary reasons for non-enrollment were ineligibility due to exclusions of low-grade glioma (n = 7) and prior BRAF inhibitor therapy (n = 7). Enrolled diagnoses were one each of histiocytosis, ameloblastoma, Ewing sarcoma, and high-grade glioma, all with BRAF V600E mutations. Treatment was overall tolerable with mostly expected grade 1/2 adverse events (AE). Grade 3 or 4 AE on treatment were acute kidney injury, hyperglycemia, and maculopapular rash. One patient came off therapy due to AE. One patient (glioma) had an objective partial response and remained on protocol therapy for 15 cycles. There was a low accrual rate on this MATCH subprotocol, with only 18% of those who matched with BRAFV600 mutations enrolling, resulting in early termination, and limiting study results (ClinicalTrials.gov Identifier: NCT03220035).

Abstract IA010: Targeting genome instability in cancer: Translating synthetic lethal biology into the clinic

Abstract Membrane-associated tyrosine- and threonine-specific Cdc2-inhibitory kinase (PKMYT1) is a cell cycle regulatory kinase that inhibits CDK1/CyclinB activity, delaying entry into mitosis in tumor cells experiencing replication stress (RS). RS is frequently induced by genetic alterations that drive premature transition from G1 to S phase, promoting genome instability and creating a synthetic lethal (SL) relationship between these specific alterations and PKMYT1 inhibition. This relationship has been demonstrated preclinically and clinically with CCNE1 amplification as well as FBXW7 and PPP2R1A deleterious mutations. These genetic alterations are common across a range of tumors including ovarian, endometrial and colorectal cancers. On this basis, we developed lunresertib (RP-6306), a first-in-class, potent and selective oral PKMYT1 inhibitor currently being investigated in phase I clinical trials (NCT04855656, NCT05147272, NCT05147350). Here we discuss the translation of pre-clinical data to the clinical setting as both monotherapy and mechanistic combinations approaches. Citation Format: Michael Zinda. Targeting genome instability in cancer: Translating synthetic lethal biology into the clinic [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr IA010.

Efficacy and safety of fruquintinib across different subgroups of patients with previously treated metastatic colorectal cancer: A meta-analysis.

e15589 Background: Most patients with mCRC eventually develop disease progression or intolerance to first- and second-line therapy. Fruquintinib, a selective oral tyrosine kinase inhibitor of VEGFRs 1, 2, and 3, has emerged as a novel treatment option for refractory mCRC. We conducted a meta-analysis to assess the safety and efficacy of Fruquintinib for the treatment of refractory mCRC compared to placebo in specific patient subgroups of interest. Methods: We systematically searched PubMed, EMBASE, and Cochrane databases for randomized controlled trials (RCTs) reporting Fruquintinib efficacy. The data extraction followed PRISMA guidelines and our protocol was registered in PROSPERO (CRD42023477783). Summary hazard ratios (HRs) of overall survival (OS) and progression-free survival (PFS) were calculated using a random-effects model. The likelihood of Fruquintinib being associated with adverse events (AEs) was expressed by odds ratios (ORs). Results: Of the 1138 studies yielded by the search, three were included, totaling 1178 patients, of whom 786 (67%) received Fruquintinib. This meta-analysis of three randomized trials assessed the clinical outcomes of Fruquintinib in the intervention group compared with placebo in refractory mCRC. Pooled results from all three studies suggested the superiority of Fruquintinib in PFS (HR: 0.29 [0.25, 0.34], 95% CI, I² = 10%, p < 0.01) and OS (HR: 0.66 [0.57, 0.76], 95% CI, p < 0.01). Notably, subgroup analysis showed that Fruquintinib was associated with improved PFS in patients with prior use of VEGF inhibitors (HR: 0.32 [0.27, 0.38], 95% CI, p < 0.01) and those with more than three prior lines of treatment (HR: 0.37 [0.25, 0.53], 95% CI, p < 0.01), RAS wild-type status (HR: 0.25 [0.13, 0.35], 95% CI, p < 0.01), or RAS mutated (HR: 0.33 [0.28, 0.40], 95% CI, p < 0.01). In the safety analysis, fruquintinib and placebo showed no significant differences in serious AEs; nonetheless, the VEGFR inhibitor was associated with more frequent grade ≥ 3 AEs (OR: 3.13 [1.15, 8.53], 95% CI, p = 0.03). Conclusions: This meta-analysis supports the efficacy of Fruquintinib for refractory mCRC regardless of previous use of VEGF inhibitors, the number of previous treatment lines, and gene RAS mutational status, without a significant increase in serious adverse events. [Table: see text]

Tazemetostat in combination with topotecan and pembrolizumab in patients with recurrent small cell lung cancer.

TPS8130 Background: Small-cell lung cancer (SCLC) is the most fatal type of lung cancer characterized by exquisite chemo-sensitivity at diagnosis and chemoresistance at relapse. Despite a highly mutated genome, patients with SCLC derive little benefit from immunotherapy. EZH2 (enhancer of zeste homolog 2) is a master epigenetic regulator of SCLC neuroendocrine cell fate and plasticity. EZH2 inhibition 1) promotes upregulation of Schlafen 11 (SLFN11) which irreversibly blocks replication in response to DNA damaging agents and 2) enhances intrinsic immune signaling, leading to constitutive MHC I recovery, sensitizing resistant SCLC models to DNA damaging chemotherapy and immunotherapy. Tazemetostat is a selective oral EZH2 inhibitor. Methods: This is an investigator-initiated, NCI Cancer Therapy Evaluation Program (CTEP) sponsored, phase I dose escalation and dose expansion study which will evaluate safety and tolerability of combination of tazemetostat with topotecan, a selective TOP1 inhibitor, and programmed cell death protein 1 (PD-1) inhibitor antibody pembrolizumab. Adult patients with relapsed/recurrent SCLC after at least platinum doublet (limited stage-SCLC) or chemo-immunotherapy (extensive stage-SCLC) and ECOG performance 0-1 are eligible. The regimen design involves a 7-day “run-in” of oral tazemetostat BID followed by 21-day cycles of tazemetostat (1-21 days), intravenous (IV) topotecan (day 1-5) and IV pembrolizumab (Day 1). The dose escalation cohort aims to determine safety and optimal doses of tazemetostat and topotecan (with standard dose of pembrolizumab) using a 3+3 design by assessing for dose limiting toxicities. The dose expansion cohort aims to assess safety, tolerability and preliminary efficacy of the combination in 15 additional patients with relapsed SCLC. The study involves collection of mandatory biopsies at pre-treatment and post-treatment (cycle 1) to gain insights into mechanism of action and resistance of the combination using single cell and spatial transcriptomic approaches. For more questions regarding enrollment and eligibility please contact Rasa.vilimas@nih.gov or anish.thomas@nih.gov . Clinical trial information: NCT05353439 .

A phase 1, open-label, dose escalation and dose expansion study to evaluate the safety, tolerability, pharmacokinetics, and antitumor activity of PF-07799544 (ARRY-134) as a single agent and in combination with PF-07799933 BRAF dimer inhibitor, in participants 16 years and older with advanced solid tumors.

TPS3180 Background: The MAPK pathway plays a role in several key signaling and phosphorylation events that contribute to tumorigenesis. Inhibition of MEK, along with RAF kinases, has proven to be a successful transformative strategy for melanoma and other MAPK pathway-altered tumors. However, the duration of clinical benefit is limited by a narrow therapeutic index, de novo and acquired resistance and poor brain penetration. PF-07799544 is a next-generation, fully brain penetrant MEK inhibitor. PF-07799933 is an oral selective ATP-competitive small-molecule RAF kinase inhibitor that suppresses BRAF signaling in BRAF V600-mutant and non-V600-BRAF mutant tumors. It displays significantly less paradoxical activation than approved BRAFi and is not “pan RAF” as it spares non-BRAF mutated-containing RAF dimers. We describe here the design of the Phase 1 study of PF-07799544 as Monotherapy or in Combination with a next generation BRAF dimer inhibitor PF-07799933 in participants with BRAF mutated (BRAFm) advanced solid tumors. Methods: The purpose of this first-in-human study is to investigate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics, and potential clinical benefits of PF-07799544 administered as a single agent in participants with advanced solid tumors (Phase 1a) and in combination with PF-07799933 in participants with BRAF Class 1, 2 and 3 mutated solid tumors with or without brain involvement (Phase 1b). Phase 1a will enroll participants with advanced solid tumors who have progressed on standard of care. The primary objective is to determine monotherapy MTD/RDE of PF-07799544. Once PK measurements indicate the potential for significant WT MEK mutation target coverage, participants with untreated and symptomatic brain metastases (bm) will be allowed to enroll. Phase 1b is comprised of multiple sub-studies, all of which evaluate PF-07799544 in combination with PF-07799933 in participants with BRAFm solid tumors who have progressed on standard of care therapies, including Class 1 BRAFi where indicated. Sub-study B: BRAFm melanoma (V600 and non-V600) will determine the MTDc/RDEc of the combination (Part 1 primary objective), followed by dose expansion cohorts (Part 2) (~80 participants): Cohort 1: BRAF V600 melanoma (asymptomatic and untreated bm permitted), Cohort 2: BRAF V600 melanoma (symptomatic bm), Cohort 3 BRAFm Class 2/3 melanoma (asymptomatic and untreated bm permitted); Sub-study C: BRAFm Class 2 or 3 advanced solid tumor Cohort 1 (asymptomatic and untreated bm permitted and Cohort 2 (symptomatic bm) (~20 each cohort). The main objectives of the dose expansion cohorts in all substudies, will be to evaluate anti-tumor activity, safety, PK and PD. Clinical trial information: NCT05538130 .

Avutometinib/defactinib and gemcitabine/nab-paclitaxel combination in first-line metastatic pancreatic ductal adenocarcinoma: Initial safety and efficacy of phase 1b/2 study (RAMP 205).

4140 Background: More than 90% of pancreatic ductal adenocarcinomas (PDAC) harbor an activating KRASmutation .Avutometinib (avuto) is an oral RAF/MEK clamp. Defactinib (defact) is an oral selective FAK inhibitor. Avuto/defact combined with gemcitabine/paclitaxel have shown synergistic antitumor activity in preclinical PDAC models. RAMP 205 (NCT05669482) is a Phase 1b/2 study assessing the safety and efficacy of avuto/defact + gemcitabine/nab-paclitaxel (GnP) in first-line metastatic PDAC. Methods: Eligible patients (pts) were enrolled and treated in 3+3 cohorts with escalating doses of avuto orally (PO) twice weekly (BIW) and defact PO twice daily (BID), both 3 out of 4 weeks, in combination with GnP dosed intravenously (IV) on a D1, D8, D15 or D1, D15 (modified) 4wk schedule (Table 1). Key eligibility criteria include histologically confirmed newly diagnosed metastatic PDAC with measurable disease, ECOG performance status (PS) ≤1, adequate organ function, and no prior treatment. Results: At the 24Jan2024 data cutoff, 18 pts were enrolled, 44% were male, 65 y median age, and 61% ECOG PS 1. Pts were enrolled to DL-1 (n=3), DL1 (n=6), DL1a (n=6), and DL2a (n=3). No dose-limiting toxicities (DLTs) were reported and the majority of treatment related adverse events (TRAEs) were mild to moderate. The most frequently reported TRAEs of any grade in the safety population (N=18) were nausea (50%), alopecia (44%), fatigue (39%), maculo-papular rash (33%), and peripheral edema (28%). The most common grade ≥3 TRAEs included alanine aminotransferase increase (17%), neutropenia (17%), peripheral edema (11%), anemia (11%), and sepsis (11%). Four patients experienced serious AEs (SAEs). Grade ≥3 treatment emergent SAEs included pulmonary embolism (n=2; unrelated), sepsis (n=2), febrile neutropenia (n=1; did not meet DLT criteria), and neutropenia (n=1). One patient discontinued treatment due to TRAE (febrile neutropenia and blood bilirubin increased). All efficacy evaluable pts (n=8) experienced a reduction in target lesions (100% disease control rate) and partial responses were observed in 6/8 (75%), 3 being confirmed at data cutoff. All efficacy evaluable pts with an elevated CA19-9 at baseline (n=7) had a ≥60% CA19-9 reduction from baseline. Conclusions: Avuto/defact and GnP are combinable and show notable preliminary efficacy in first-line metastatic PDAC based on RECIST v.1.1 criteria and CA19-9 levels. No DLTs were reported across the 4 dosing cohorts/schedules and safety signals were consistent with previous clinical data. Updated safety and efficacy will be reported. Clinical trial information: NCT05669482 . [Table: see text]

Depletion of histone H3K27 demethylase exerts anti-tumor activity as a monotherapy and in combination therapy with ceralasertib in non-small cell lung carcinoma.

e20035 Background: Lung cancer is one of the most frequently diagnosed cancers and is the leading cause of cancer-related death worldwide. Non-small cell lung carcinoma (NSCLC) represents 85% of lung cancers and is the most common type with poor prognosis. The lysine-specific demethylase UTX (gene name KDM6A) demethylates H3K27me2/3 at genes and enhancers and have been shown to support oncogenic transcription factors. We hypothesize that UTX is a highly pleiotropic factor in tumorigenesis and may plays a critical role in controlling DNA replication-associated gene activation as well as in replication stress-related DNA damage repair. Methods: To evaluate the role of UTX in tumorigenesis, shRNA-mediated UTX knockdown was employed in NCI-H1975 cells followed by cell cycle and cell proliferation assays. In the UTX-knocked down NCI-H1975 cells, target genes involved in DNA replication and DNA damage repair were discovered by RNA sequencing and further validated with RT-qPCR. Effects of UTX depletion on DNA replication and radiation-induced DNA repair were analyzed by immunofluorescence. Effects of UTX depletion on cell cycle arrest and the ATR–CHK1 checkpoint signaling pathway were analyzed by flow cytometry and immunoblotting. In vivo response to UTX inhibition monotherapy (UTX knockdown) and combination therapy of UTX knockdown with ceralasertib, a selective ATR kinase inhibitor, was evaluated in dox-inducible UTX knockdown NCI-H1975 xenografts. Results: Induction of UTX knockdown significantly reduced the NCI-H1975 tumor volume compared to the control group, showing anti-tumor activity. Furthermore, loss of UTX induced hyperactivation of ATR–CHK1 checkpoint signaling pathway, suggesting the UTX-depleted tumor cells attempt to alleviate replication stress to escape from apoptosis. To inhibit the UTX-depletion induced ATR–CHK1 pathway, ceralasertib (formerly AZD6738), an oral potent selective inhibitor of ATR, was combined with UTX-knockdown for in vitro and in vivo evaluation. Consistent with in vitro cell-based assay, combination therapy of ceralasertib with UTX depletion showed enhanced tumor growth inhibition and regression in the NCI-H1975 xenograft model. Conclusions: Our findings provide new insights into a pro-oncogenic role of UTX in supporting tumor maintenance via engaging DNA replication and repair pathway. Depletion of UTX alone may serve as a new therapeutic target in non-small cell lung carcinoma; and further combination with ceralasertib enhances the anti-tumor activity of UTX knockdown by inhibiting the ATR–CHK1 checkpoint signaling pathway.

Efficacy and safety of SHR-2554 in advanced epithelioid sarcoma: A phase 2 trial.

11549 Background: Epithelioid sarcoma (ES) is a rare and aggressive subtype of soft-tissue sarcoma. The loss of SMARCB1 (INI1) expression which leads to oncogenic dependence on the transcriptional repressor EZH2 has been observed in over 90% of ES. Patients (pts) with metastatic ES have a poor prognosis. We investigated the efficacy and safety of SHR-2554, an oral selective EZH2 inhibitor, in pts with refractory ES. Methods: To be eligible for inclusion, pts had to fulfill the following criteria: 8 years or older; histologically confirmed advanced or metastatic ES with loss of INI1 or upregulated mRNA level of EZH2; progressive disease after at least one line of doxorubicin-containing chemotherapy; the presence of measurable disease according to RECIST 1.1; an ECOG performance status of 0-1. Pts received SHR2554 (350 mg, bid, po) until disease progression or unacceptable toxicity. The primary endpoint was progression-free rate at 12 weeks. A Simon two-stage design was applied. If there were 3 pts remaining progression-free at 12 weeks within the first 9 pts, the cohort would expand to 17 pts and the outcome would be positive if more than 7 pts remained progression-free at 12 weeks. Results: Between Jul 2021 and Dec 2023, a total of 17 pts were enrolled and received at least 1 dose of SHR-2554. The median age was 32 years (range 8-57) and 41.2% were males. 9 (52.9%) pts had received immunotherapy targeting PD-1/L1 and 6 (35.3%) pts had received anti-angiogenesis therapy before enrollment. The median line of previous treatment was 2 (range 1-4). Loss of INI1 was confirmed in 14 (82.4%) pts. Tumor response was evaluated in 14 pts at data cutoff. 9 (64.3%) of 14 pts remained progression-free at 12 weeks. The primary endpoint was met. Based on investigator assessment, 3 (21.4%) of 14 pts achieved partial response and 8 (57.1%) pts had stable disease as best response. Adverse events (AEs) were generally mild. The most common treatment-related hematological AEs were anaemia, platelet count decreased and hyperuricaemia. Conclusions: SHR-2554 showed promising efficacy and an acceptable safety profile in pts with refractory ES, warranting further investigation. Clinical trial information: ChiCTR2100046099.

Safety and efficacy of ifebemtinib (IN10018) combined with D-1553 in non-small-cell lung cancer (NSCLC) with KRAS G12C mutation: Results from a phase Ib/II study.

8605 Background: KRAS G12C mutation is present in about 12-14% of NSCLC population. Ifebemtinib (IN10018) is a highly potent and selective oral inhibitor of focal adhesion kinase (FAK). D-1553 (garsorasib) is a novel oral and potent KRAS G12C inhibitor. Preclinical data showed that ifebemtinib in combination with KRAS G12C inhibitors had synergistic anti-cancer effect in multiple KRAS G12C mutant cancer models. This study is to evaluate the safety and antitumor activity of ifebemtinib combined with D-1553 in solid tumors with KRAS G12C mutation. Here we report the preliminary data from phase II part of front-line NSCLCs with KRAS G12C mutation. Methods: Locally advanced or metastatic NSCLC subjects without prior systemic anti-cancer therapy were enrolled. Subjects were required to have KRAS G12C mutation in tumor tissues. All subjects were assigned to the recommended phase II dose (RP2D) of ifebemtinib (100mg qd) + D-1553 (600mg bid). Results: As of 31 January 2024, 33 front-line NSCLC subjects with KRAS G12C mutation were enrolled and received the combination therapy. Median age was 65yrs (range 58, 83), 93.9% were male, and 81.8% had stage IV metastatic disease. Median study follow-up (FU) was 2.2 months (range 1.1, 9.2). The safety profile of the combination therapy is comparable to each single agent without additive toxicities. No ifebemtinib- or D-1553-related death was reported. Four subjects (12.1%) had ifebemtinib-related SAEs (diarrhea, enteritis, oedema peripheral and proteinuria) as assessed by investigators, and all SAEs were also considered D-1553 related. Six subjects (18.1%) had ≥ Grade 3 ifebemtinib-related AEs as assessed by investigators, and all were also D-1553 related AEs. The majority of ifebemtinib-related AEs were CTCAE Grade 1 or 2. There was no event leading to study treatment discontinuation. We have observed continuing tumor shrinkage in almost all subjects who had at least 2 tumor assessments. Among 16 subjects with ≥ 3 months FU, preliminary efficacy found that 14 had best overall response of partial response (PR) including 12 confirmed PRs and 2 unconfirmed but still in treatment, 1 had stable disease (SD), and 1 had progressive disease (PD). The overall response rate (ORR) was 87.5% (95%CI: 56.6, 96.2), and disease control rate (DCR) was 93.8% (95%CI: 63.6, 98.5). The median duration of response (DOR), median progression-free survival (PFS) and overall survival (OS) have not been reached. Conclusions: The combination of ifebemtinib and D-1553, as a dual-oral regimen, showed promising antitumor activity and manageable safety profile in KRAS G12C mutant front-line NSCLC population. Long term follow-up is needed to assess the potential of such novel combo. Clinical trial information: NCT06166836 ; NCT05379946 .

Fulvestrant with or without the cyclin-dependent kinase 7 (CDK7) inhibitor samuraciclib in advanced hormone receptor positive (HR+) breast cancer after CDK4/6 inhibition: Phase II SUMIT-BC study.

TPS1126 Background: CDK7 enhances oncogene transcription and upregulates anti-apoptotic genes, accelerates the cell cycle via CDK phosphorylation, and activates estrogen receptors (ERs) that can drive resistance to hormonal therapy in cancer. CDK7 inhibition therefore represents a potential anticancer strategy in cancer. Samuraciclib (CT7001) is a small molecule, ATP competitive, selective oral inhibitor of CDK7 that inhibits these key effects of CDK7. Samuraciclib had a favorable safety profile and showed clinical activity when combined with fulvestrant in a phase I study in patients with HR+/HER2− advanced breast cancer (BC) who had previously been treated with a CDK4/6 inhibitor. Patients with no detectable TP53 mutation in ctDNA at baseline and those without baseline liver metastases appeared to have better outcomes. The instant release capsule formulation of samuraciclib used in this study released large amounts of samuraciclib high in the gastrointestinal (GI) tract, which may have contributed to the observed low grade GI adverse events, which were managed with prophylaxis and counselling (1). Methods: A phase 2 open-label randomized study has been designed to evaluate the efficacy, safety, pharmacokinetics (PK), and quality of Life (QoL) of samuraciclib combined with fulvestrant compared to fulvestrant monotherapy (SUMIT-BC; NCT05963984). Eligible patients (n=60) are ≥18 years, have histologically or cytologically confirmed ER+/HER2− advanced or metastatic BC not amenable to resection or radiotherapy of curative intent, have received an aromatase inhibitor combined with a CDK4/6 inhibitor in the adjuvant or advanced setting, are receiving a luteinizing hormone-releasing hormone agonist if pre/perimenopausal, and have RECIST v1.1 evaluable disease. Prior SERD, mTOR inhibition, or chemotherapy for advanced BC are not permitted. All patients undergo baseline Guardant360 ctDNA analysis to establish TP53 and other mutation status. Patients are randomized 1:1:1 to fulvestrant alone (500 mg IM administered on days 1, 15 and 29 and then monthly), fulvestrant and samuraciclib 240 mg QD, or fulvestrant and samuraciclib 360 mg QD. In preparation for phase 3 development, a novel single tablet formulation of samuraciclib is used, which may enhance GI tolerability. Patients undergo RECIST v1.1 evaluation at baseline, every 8 weeks until week 48, and every 12 weeks thereafter. The primary endpoint is clinical benefit response at 24 weeks. Secondary endpoints are tolerability, progression free survival, overall response rate, duration of response, and PK of fulvestrant and samuraciclib. QoL (Functional Assessment of Cancer Therapy - Breast questionnaire [FACT-B]) and correlations between TP53 mutation and efficacy/safety will be assessed. 1. Coombes et al. Nature Comms 2023. Clinical trial information: NCT05963984 .