28-day Cycle Research Articles

INNV-27. TEMOZOLOMIDE FOR PATIENTS WITH AGGRESSIVE PITUITARY TUMORS: A CASE SERIES

Abstract BACKGROUND Pituitary adenomas are often effectively managed with medical therapy, surgery, and radiation therapy. However, up to 15% of pituitary neoplasms exhibit rapid growth, invasive behavior, or, rarely, metastasize despite optimal standard treatments. Temozolomide is associated with a survival benefit for patients with these aggressive pituitary tumors. METHODS We present a case series of 8 patients with an aggressive pituitary tumor (APT) or pituitary carcinoma (PC) treated with temozolomide. RESULTS Eight patients (3 female, median age at diagnosis 44) with APT (n=6) or PC (n=2) were treated. A variety of pituitary tumor types were represented (1 prolactinoma, 5 corticotroph adenomas, 1 gonadotroph adenoma, 1 thyrotropinoma). Prior to temozolomide initiation, patients underwent a median 5 treatments including medical management (n=4), surgery (n=7), radiation therapy (n=7). Temozolomide was started at median 3.5 recurrence. Median treatment duration was 6 cycles (n=6, 150-200 mg/m2 days 1-5, 28-day cycles; n=1, 75 mg/m2, days 1-21, 28-day cycles). Seven patients experienced progression after temozolomide treatment, median progression-free survival (PFS) was 4 months. One patient remains on treatment, progression-free at 5 months. MGMT methylation status was assessed for 3 tumors. Among 2 patients with MGMT promoter methylated tumors, PFS was 4 months for one patient, the other remains on treatment. For one patient with MGMT promoter unmethylated corticotroph adenoma, PFS was 9 months. No ≥ grade 4 toxicities were noted. Most common toxicities were nausea (n=5), thrombocytopenia (n=3), and fatigue (n=2). CONCLUSION In this group of heavily pretreated patients, temozolomide monotherapy was well-tolerated and associated with median PFS of 4 months. Interestingly, PC patients had longer PFS at 9 months and 24 months. Our findings support use of single-agent temozolomide chemotherapy for patients with APT/PC, but further prospective analysis is needed to identify patients more likely to benefit from treatment and optimal timing of chemotherapy initiation.

CTNI-29. A PHASE 1B STUDY TO EVALUATE THE SAFETY, PHARMACOKINETICS, AND OBJECTIVE RESPONSE OF LP-184 ALONE AND IN COMBINATION WITH SPIRONOLACTONE IN IDH WILD TYPE GLIOBLASTOMA AT FIRST PROGRESSION

Abstract LP-184 is a fully synthetic small molecule alkylator of the acylfulvene therapeutics class that induces DNA double-strand breaks and improves survival in orthotopic GBM xenograft models. In preclinical studies, LP-184 is brain penetrant with a brain tumor/plasma concentration ratio of 0.2. DNA damage induced by acylfulvenes is repaired via transcription-coupled nucleotide excision repair (TC-NER) mediated by ERCC complexes. GBM with intrinsic or pharmacologically induced DNA Damage Repair deficiency (dDDR) may preferentially respond to LP-184, independent of MGMT status. LP-184 is currently under investigation in a first-in-human Phase 1a dose-escalation safety study (NCT05933265) in adult patients with advanced solid tumors including GBM, with no dose-limiting toxicities to date at dose level 6. Following determination of the Maximum Tolerated Dose and/or Recommended Phase 2 Dose from Phase 1a, the selected expansion dose will be assessed in a Phase 1b study to evaluate the safety, pharmacokinetics, and objective response of LP-184 alone and in combination with spironolactone in IDH wild type glioblastoma at first progression. Spironolactone is a brain penetrant FDA approved agent that proteolytically degrades the TC-NER component ERCC3, thereby creating dDDR. Two rGBM cohorts will be enrolled according to a Simon’s 2-stage optimal design: (i) LP-184 alone (days 1 and 8 in a 21-day cycle, as intravenous infusion over 30 minutes) and (ii) combination of LP-184 and spironolactone (200 mg orally daily in conjunction and before the LP-184 infusion). In the first stage, 10 response evaluable subjects will be enrolled. If 1 or more of the first 10 response evaluable subjects achieve an objective response, 19 further subjects may be accrued in the second stage. In each cohort, at least 5 subjects will undergo planned tumor resection and will be treated with LP-184 or the combination the day prior to surgery to evaluate PK/PD.

CTIM-19. A PHASE 1, SAFETY LEAD-IN AND RANDOMIZED, OPEN-LABEL, PERIOPERATIVE STUDY OF VORASIDENIB COMBINED WITH PEMBROLIZUMAB IN RECURRENT OR PROGRESSIVE ENHANCING IDH-1 MUTANT GLIOMA: TRIAL IN PROGRESS

Abstract BACKGROUND Vorasidenib (VOR) is an oral, brain-penetrant dual inhibitor of isocitrate dehydrogenase 1/2 mutant (mIDH1/2) enzymes. VOR is being investigated in a phase 3 study in residual or recurrent grade 2 non-enhancing gliomas, in which interim analysis showed VOR significantly improved progression-free survival and delayed time to next intervention. A prior neoadjuvant perioperative study in recurrent, non-enhancing grade 2/3 gliomas showed that VOR treatment was associated with interferon signal activation and increased T-cell infiltration, suggesting 2-hydroxyglutarate suppression may prime the tumor immune microenvironment for immune checkpoint blockade. This study (NCT05484622) evaluates the safety and tolerability of VOR+pembrolizumab to determine the recommended combination dose (RCD) of VOR (safety lead-in phase) and evaluates CD3+ T-cell infiltration in tumors following a 28-day preoperative period. METHODS Enrollment: US patients with recurrent or progressive grade 2/3 mIDH1 R132H glioma. Key eligibility: measurable enhancing disease, Karnofsky Performance Status ≥70, resectable (perioperative phase only). Following a March 2024 protocol amendment, inclusion criteria were expanded to include patients with oligodendroglioma in addition to patients with astrocytoma. Safety lead-in dosing: Cohort 1, VOR 40mg QD+pembrolizumab 200mg Q3W in 21-day cycles. The perioperative phase is randomized 1:1:1 to preoperative combination, VOR 40mg QD, or untreated for 28 (+7) days; all patients could opt to receive the VOR RCD in combination with pembrolizumab 200mg Q3W postoperatively. Primary objectives: safety and tolerability of VOR RCD administered with pembrolizumab; CD3+ T-cell infiltration in resected tumors following presurgical treatment with combination compared to untreated tumors. RESULTS Seven patients with recurrent or progressive enhancing grade 2/3 astrocytoma with an mIDH1 R132H were dosed in the safety lead-in phase. No dose-limiting toxicities were detected during this phase. CONCLUSION VOR 40mg QD+pembrolizumab 200mg Q3W was confirmed as the RCD for the perioperative phase. This phase was opened to enrollment in May 2023, and recruitment is ongoing.

CTNI-66. IDH-MUTANT GLIOMA PATIENTS TREATED WITH VORASIDENIB: ONGOING DATA FROM THE VORASIDENIB EXPANDED ACCESS PROGRAM

Abstract BACKGROUND Vorasidenib (VOR) is an oral, brain-penetrant dual inhibitor of mutant isocitrate dehydrogenase 1/2 (mIDH1/2) demonstrating clinical efficacy and safety in patients with mIDH1/2 glioma in the phase 3 INDIGO study (NCT04164901). Servier launched an expanded access program (EAP, NCT05592743) in November 2022 designed to provide access to VOR for patients with mIDH1/2 glioma. Early clinical outcomes of patients treated in this EAP are presented. METHODS Eligible participants were aged ≥12 years with mIDH1/2 glioma and, in the opinion of the treating oncologist, would potentially benefit from treatment with VOR. Safety assessments occur every two weeks for the first two 28-day cycles, then monthly for the duration of treatment. RESULTS As of the March 31, 2024 data cutoff, 71 participants have initiated treatment with VOR. Mean (SD) age was 42.7 (14.8) years; 39 (55%) were male; and 34 (48%) with astrocytoma. mIDH mutation status was 46 (65%) mIDH1. One participant had separate tumors with either mIDH1 or mIDH2 identified. The majority of participants had grade 2 gliomas (n=51 [72%]) and non-contrast–enhancing disease (n=49 [69%]). As of the data cutoff, 62 (87%) participants remain on treatment, with the majority initiating treatment within the past 6 months (n=49 [69%]). Nine (13%) participants have discontinued treatment due to: radiographic progressive disease (n=3); clinical progressive disease (n=4); adverse event (AE) unrelated to treatment (n=1); or other reason (n=1). Three participants have died (disease progression [n=2], unrelated infection [n=1]). At least one AE of any grade was seen in 35 (49%) participants, with 4 (6%) experiencing unrelated serious AEs. Eight (11%) patients had AEs of special interest (defined as grade 2 or higher ALT/AST elevations). Ten (14%) patients had AEs that led to dose interruption and one (1%) patient had dose reduction. Additional treatment duration and various subgroup analyses will be presented.

NCOG-05. HEALTH-RELATED QUALITY OF LIFE (HRQOL) IN THE PHASE 2 FIREFLY-1 (PNOC026) TRIAL OF THE TYPE II RAF INHIBITOR TOVORAFENIB IN RELAPSED/REFRACTORY (R/R) PEDIATRIC LOW-GRADE GLIOMA (PLGG)

Abstract BACKGROUND Despite favorable long-term survival, ongoing disease and treatment-related morbidity substantially impact the HRQOL of patients with pLGG. Tovorafenib is a selective, CNS-penetrant, type II RAF inhibitor. Results from the ongoing FIREFLY-1 (NCT04775485) phase 2 study (Kilburn LK, et al. Nat Med. 2023) showed clinically meaningful responses and a manageable safety profile in pLGG. Vision remained stable or improved in 89% of evaluable patients with optic pathway gliomas (Nysom K, et al. Neuro-Oncol. 2023). METHODS FIREFLY-1 arm 1 patients 6 months–25 years of age with RAF-altered r/r pLGG received tovorafenib 420 mg/m2 weekly (600 mg max) in 28-day cycles. Exploratory measures included longitudinal assessment of PedsQL in patients ≥2 years of age. PedsQL 3.0 Cancer Module child self-reports Total Score and 8 subscales were used to assess HRQOL from 0 (worst)–100 (fewer problems/symptoms) (as of December 22, 2022) baseline (BL) to cycle 13 (C13) in patients ≥5 years of age. RESULTS For the PedsQL 3.0 Cancer Module, 51 completed self-reports at BL, and 32 at C13 due to continued attrition over time. Median Total Score was 81.5 (range: 46.3-100) at BL and 85.2 (range: 50-100) at C13. At C4, 16% worsened (decrease >10 points) and 11% improved (increase >10 points); by C13, 11% worsened and 33% improved. For Cognitive Problems, patients scored a median of 75 (range: 5-100) at BL and 85 (range: 20-100) at C13, with 11% and 26% improved at C4 and C13, respectively. A similar trend was seen with Nausea. Pain and Hurt remained even throughout (median: 87.5). Treatment Anxiety was not a major concern (median: 100, C1-C13); Procedural Anxiety improved over time (median: 58.3 BL; 79.2 at C13). CONCLUSIONS HRQOL generally remained stable, or improved, in the majority of patients with r/r pLGG during the first year of treatment with tovorafenib.

CTNI-53. A GLOBAL, RANDOMIZED, DOUBLE-BLINDED, PHASE 3 STUDY OF VORASIDENIB VERSUS PLACEBO IN PATIENTS WITH ADULT-TYPE DIFFUSE GLIOMA WITH AN IDH1/2 MUTATION (INDIGO): UPDATED EFFICACY RESULTS

Abstract INTRODUCTION The Phase 3 INDIGO study (NCT04164901) evaluated vorasidenib, an oral, brain-penetrant, dual inhibitor of mutated isocitrate dehydrogenase 1/2 (mIDH1/2), in patients with mIDH1/2 diffuse glioma. The primary endpoint of progression-free survival (PFS) per blinded independent review committee (BIRC), and key secondary endpoint of time to next intervention (TTNI), were met in the positive, preplanned second interim analysis (IA2). The study was unblinded in March 2023 following independent data monitoring committee recommendation. Here, we present results after an additional 6 months of follow-up between the database lock for IA2 (September 6, 2022) and study unblinding (March 7, 2023). METHODS Patients with residual/recurrent grade 2 mIDH1/2 oligodendroglioma or astrocytoma were enrolled (≥12 years; Karnofsky Performance Status ≥80; measurable non-enhancing disease; surgery as only prior treatment; no immediate need of chemoradiotherapy). Patients were randomized 1:1 to vorasidenib 40 mg or placebo daily in 28-day cycles. RESULTS Overall, 331 patients were randomized (median age: 40.0 years; oligodendroglioma: 172; astrocytoma: 159). As of March 7, 2023, 123/168 (73%) patients remained on vorasidenib and 72/163 (44%) remained on placebo. PFS per BIRC remained in favor of vorasidenib (HR, 0.35; 95% CI, 0.25–0.49), and was consistent with PFS per investigator assessment (HR, 0.34; 95% CI, 0.23–0.50). Median PFS per BIRC: vorasidenib, not estimable (NE; 95% CI, 22.1–NE); placebo, 11.4 months (95% CI, 11.1–13.9). TTNI also remained in favor of vorasidenib (HR, 0.25; 95% CI, 0.16–0.40). Median TTNI: vorasidenib, NE (95% CI, NE–NE); placebo, 20.1 months (95% CI, 17.5–27.1). No new safety signals emerged. CONCLUSIONS Vorasidenib is a targeted therapy for patients with predominantly non-enhancing mIDH1/2 diffuse glioma following surgical intervention, as shown in the INDIGO population. These additional 6 months of follow-up confirm the previously reported statistically significant and clinically meaningful improvements in PFS and TTNI with vorasidenib.

CTNI-70. RESULTS FROM THE PHASE 1 AND PHASE 1 EXPANSION COHORTS OF SJ901: A PHASE 1/2 TRIAL OF SINGLE-AGENT MIRDAMETINIB (PD-0325901) IN CHILDREN, ADOLESCENTS, AND YOUNG ADULTS WITH LOW-GRADE GLIOMA

Abstract BACKGROUND Mirdametinib is an investigational, oral, selective MEK1/2 inhibitor (MEKi) with high blood-brain-barrier penetration. We hypothesized that mirdametinib would benefit patients with pediatric low-grade gliomas (pLGG) and launched SJ901 (NCT04923126) to determine the recommended Phase 2 dose (RP2D), safety, and efficacy. METHODS For Phase 1 and Phase 1 expansion patients were required to be ≥2 and <25 years-old, MEKi-naive, and have recurrent/progressive pLGG with biopsy-proven MAPK pathway activation (except BRAF V600). Three dose levels (DL1: 2 mg/m2/dose BID, DL2: 2.5mg/m2/dose BID, DL3: 3mg/m2/dose BID administered continuously in 28-day cycles) were evaluated with an expansion cohort to assess the highest tolerated dose level in a total of 12 patients. RP2D was defined as the dose causing ≤3 dose-limiting toxicities (DLTs) in 12 patients within the first cycle of therapy. RESULTS Between June 2021 and December 2023, 23 patients enrolled (DL1=5, DL2=6, and DL3=12). Median age was 8.4 years (2.5-21.9); 52% female. Alterations were seen in BRAF (n=12;52%), FGFR1 (n=5;22%), NF1 (n=3;13%), RAF1 (n=2;9%), and MYB (n=1;4%). The median follow-up time was 14.6 months (3.2-27.8). One DLT was observed (grade-3 thrombocytopenia). Seventeen (74%) patients completed or remain on-therapy; 4(17%) stopped for progression (2 FGFR1; 1 MYB; 1 BRAF); 2 discontinued for toxicities [1 grade-2 rash; 1 grade-4 creatine phosphokinase (CPK) elevation]. Dose modifying adverse events included weight gain, CPK elevations, and rash. No significant cardiac or retinal toxicity was observed. Twelve (63%) of 19 patients with measurable tumors achieved an objective response (1 major, 6 partial, 5 minor). The median time to ≥ minor response was 5.4 months (1.7-7.3). DL3 (3 mg/m2/dose BID) was declared the RP2D. CONCLUSIONS Mirdametinib is well-tolerated and has promising clinical activity in patients with recurrent/progressive pLGG. Phase 2 is ongoing to establish safety and efficacy in newly diagnosed, recurrent/refractory tumors, and in patients with prior MEKi exposure.

CTNI-19. MYCOPHENOLATE MOFETIL TARGETS GLIOBLASTOMA DE-NOVO PURINE METABOLISM TO OVERCOME CHEMORADIATION RESISTANCE IN NEWLY DIAGNOSED AND RECURRENT GLIOBLASTOMA

Abstract Glioblastoma prefer de-novo purine synthesis while normal brain prefers resource-efficient salvage pathway. Mycophenolate mofetil (MMF) disrupts de-novo purine metabolism by inhibiting a key enzyme, IMPDH. The pre-clinical evidence of MMF improving radiation and temozolomide efficacy in glioblastoma models led to this first-in-human phase 0/1 trial (NCT04477200) to assess the tolerability of MMF with chemoradiation in glioblastoma, MPA accumulation, and purine synthesis inhibition in tumor. Tissues from eight phase 0 recurrent glioblastoma subjects, receiving MMF ranging 500-2000mg BID one-week pre-operatively, were analyzed using mass spectrometry. Both enhancing and non-enhancing tumor yielded >1µM active drug metabolite, and the GTP/IMP ratio was decreased by 75% in enhancing tumor in MMF-treated patients compared to untreated controls (p=0.009). In phase 1 study, adult patients were given MMF ranging 1000-2000mg PO BID using TITE-CRM dosing. Twenty-one recurrent glioblastoma patients (target N=30) received MMF one-week prior to and concurrently with re-irradiation (40.5 Gy) with no dose-limiting toxicities (DLTs). Thirty newly diagnosed glioblastoma patients received MMF one-week prior to and concurrently with chemoradiation, followed by MMF one-day before and during 5 days of each adjuvant temozolomide cycles. In the newly diagnosed cohort, there was no DLT with temozolomide and MMF, however, with both temozolomide and radiation, there were five DLT instances noted at 2000mg BID (G3 hemiparesis, G3 cognitive disturbance, G3 fatigue, G4 thrombocytopenia x2): all were reversible. Interim phase 1 median overall-survival in recurrent MGMT-methylated and unmethylated subjects were 16.1 (N=10) and 6.1 (N=11) months, and in newly diagnosed subjects, 27.2 (N=8) and 14.2 months (N=22) respectively. Median follow ups were 7.4 (recurrent) and 23.2 months (new diagnosis). MMF combined with chemoradiation is reasonably well tolerated in glioblastoma patients with promising evidence of drug accumulation in glioblastoma, effective target engagement and inhibition of purine synthesis, leading to a recommended phase 2 dose of MMF 1500mg BID.

CTNI-73. ASSESSMENT OF MOLECULAR ALTERATIONS IN NEWLY DIAGNOSED GBM MGMT-UNMETHYLATED PATIENTS TREATED WITH VAL-083

Abstract Glioblastoma (GBM) commonly features molecular alterations in the TERT, EGFR, PTEN, and TP53 genes, which contributes to uncontrolled cell growth, evasion of apoptosis, and enhanced tumor cell survival. VAL-083 is a bi-functional DNA-targeting agent which rapidly induces inter-strand DNA cross-links at N7 and O6-guanine inducing double-strand breaks causing cell death independently of MGMT DNA repair and DNA mismatch repair deficiency. VAL-083 was evaluated in an open-label, biomarker-driven, phase 2 trial in MGMT-unmethylated, bevacizumab-naïve GBM patients. The molecular profile of tumors from a newly diagnosed GBM patient subgroup who received VAL-083 alone after chemo-radiation with concurrent TMZ, was determined in order to correlate with clinical outcomes. Thirty-four (34/36, 94.4%) patients who received 30 mg/m2 VAL-083 (days 1-3 of 21-day cycle) had available next-generation sequencing data on their primary tissue. Patient median age was 54.8 years (5-95pth: 29.8-66.0), median KPS was 90 (5-95pth: 80-100) and 58.8% were males. The median number of cycles of VAL-083 was 7.5 (5-95pth: 1-12). There were 5 dose reductions due to toxicity. The median time to progression (PFS) and overall survival (OS) were 9.2 mo (95%CI: 7.6-10.2) and 16.5 mo (95%CI: 13.3-19.0), respectively. The mean number of molecular alterations was 3.9 (5-95pth 1-8). Six (17.6%) patients had gene fusions. The most common molecular alterations were TERT promoter (91.2%), EGFR amplification (amp) (52.9%), PTEN (50.0%), EGFR (20.6%), and TP53 (20.6%). Additional alterations (in ≥2 patients; 6%) included EGFR-EGFR (EGFRvIII), BRCA2, CDKN2A/B, CDK4/6 amp, MDM2/4 amp, NF1, NOTCH1, PIK3R1 and RB1. While TP53 mutations showed a trend as predictors for time to progression (P 0.027), this was not observed with OS. None of the molecular alterations were predictors of number of treatment cycles or dose reductions. No specific molecular alterations were identified that predicted either improved or poorer patient outcome, during treatment with VAL-083. Clinicaltrials.gov identifier: NCT02717962.

CTNI-62. EVALUATION OF SAFER-SEQS CTDNA ASSAY OPTIMIZED FOR DETECTING LOW CTDNA COUNTS FROM CSF AND PLASMA: ASSESSING SENSITIVITY AND FEASIBILITY FOR CLINICAL IMPLEMENTATION

Abstract BACKGROUND Gliomas with BRAF alterations are often difficult to treat in the recurrent setting due to emergent resistance to FDA-approved targeted therapies. Additionally, it is difficult to assess response to therapy given the limitations of radiographic techniques and the infeasibility of serial tissue sampling. This protocol will serve as a prototype for determining the feasibility of using CSF and plasma circulating tumor DNA (ctDNA) as biomarkers for response to a novel-BRAF inhibitor, plixorafenib. Plixorafenib is a small-molecule selective inhibitor of Class 1 and 2 BRAF mutations that does not induce paradoxical reactivation of MAPK signaling. METHODS This clinical trial is designed as a single institution, signal-finding study to demonstrate the feasibility and sensitivity of detecting ctDNA at baseline and after one month of treatment with plixorafenib (primary endpoint). In addition, we will evaluate the correlation of ctDNA with disease status over time and response rate to plixorafenib. Patients aged 18 years or older with measurable recurrent BRAF-V600 mutant glioma (by RANO 2.0), who have received prior BRAF and/or MEK inhibitor therapy will be screened and consented for the study prior to surgery. Leptomeningeal disease allowed. A total of 12 evaluable patients will be enrolled. Patients will undergo clinically-indicated resection or biopsy for confirmation of disease progression and characterization of putative resistance alterations. All patients will have a ventricular reservoir placed at time of surgery with CSF and plasma sampling. Patients will initiate the study drug (oral plixorafenib 900mg daily with cobicistat 150mg daily) when clinically recovered from surgery. Patients will take the drug continuously for 28-day cycles. MRI, CSF, and plasma assessments will occur approximately every two months to evaluate disease status. Enrollment is planned to begin November, 2024.

CTNI-61. PRELIMINARY RESULTS OF A PHASE I/II TRIAL OF SELINEXOR AND TEMOZOLOMIDE IN RECURRENT GLIOBLASTOMA

Abstract BACKGROUND Selinexor (SEL) is a first-in-class XPO1 inhibitor with potent antitumor activity through the nuclear retention and reactivation of tumor suppressor proteins, reduced translation of oncogenes, and decreased expression of anti-apoptotic proteins. As a single agent, SEL has demonstrated brain penetration and clinically relevant responses in glioblastoma. We seek to enhance the effect and benefit of SEL by priming with temozolomide (TMZ). METHODS Through an NCI Project Team, we developed a multi-institutional phase I/II clinical trial which opened across the NCI Experimental Therapeutics Clinical Trial Network. Eligibility included histologically confirmed 1st recurrent MGMT promoter methylated glioblastoma. We evaluated safety, tolerability, and dose finding with an IQ 3 + 3 design of TMZ 150mg/m2 on days 1-5 of a 28-day cycle plus SEL on days 8 and 15. RESULTS From October 2022 to March 2024, we enrolled 12 patients (n=11 evaluable) into phase I of the study. Patient characteristics included 82% male, median age 62 (range 50-77), 64% white. The median number of cycles administered was 6 (range 1-12). Two dose levels (SEL 60mg and SEL 80mg) were evaluated. No dose-limiting toxicities (DLTs) were observed. The most common treatment related adverse events were nausea (58%), decreased platelet count (50%), fatigue (50%), constipation (42%), vomiting (25%), decreased lymphocyte count (25%), and decreased neutrophil count (25%). Grade 3+ treatment related adverse events included nausea, grade 3 (n=1); decreased lymphocyte count, grades 3-4 (n=2); and anorexia, grade 3 (n=1). Phase I has completed enrollment and the recommended phase II dose will be SEL 80mg. Additional results will be presented. CONCLUSION Results suggest that a sequential dosing regimen of SEL+TMZ is feasible, well-tolerated, and may minimize the cumulative toxicity of SEL. The phase II randomized portion of this trial is enrolling nationwide and will investigate efficacy and candidate molecular signatures of vulnerability (NCI #10505, NCT05432804).

NCOG-07. SAFETY OF ONC201 TREATMENT IN PATIENTS WITH PREVIOUSLY TREATED H3 K27M-MUTANT GLIOMA: RESULTS FROM ONC028, AN ONGOING COMPASSIONATE USE PROGRAM

Abstract PURPOSE H3 K27M-mutant diffuse midline glioma (DMG) has a poor prognosis, with a median overall survival of 1 year and no proven treatments beyond radiotherapy. ONC201 (dordaviprone), a first-in-class imipridone, previously demonstrated durable responses in patients with recurrent H3 K27M-mutant DMG. The present analysis reports safety data from ONC028, a compassionate use program (CUP) for patients with previously treated H3 K27M-mutant glioma. METHODS ONC028 is an expanded access program that provides ONC201 monotherapy to patients with H3 K27M-mutant glioma. Eligible patients are adults or pediatric patients with H3 K27M-mutant glioma, prior therapy including at least radiation, and adequate organ function. Patients must be ineligible for enrollment in other ongoing clinical studies evaluating ONC201. ONC201 is administered orally once weekly at 625 mg or dose-equivalent based on body weight for pediatric patients. MRIs are performed every two 28-day cycles for the initial 12 months, thereafter every 2-3 cycles. Treatment continues until disease progression, unacceptable adverse events (AEs), or withdrawal of consent. Treatment may continue post-progression at the discretion of the treating physician. Bevacizumab use for radiation necrosis or symptom management is acceptable. AEs are assessed by NCI CTCAE v5.0 criteria. RESULTS The 422 enrolled patients include 191 adults (45.2%) and 231 children (54.7%); 87.1% had a performance score ≥60 and the most common tumor location was the pons (57.3%). Any-causality Grade ≥3 AEs have been reported in 200 patients (47.4%). Grade ≥3 treatment-related AEs (TR-AEs) were reported in 19 (4.5%) patients; the commonest was decreased lymphocyte count, occurring in 3 (0.7%) patients. Any-causality serious AEs (SAE) were reported in 43.1% (n=182) patients. There were 10 (2.4%) patients with reports of treatment-related SAEs, the commonest were ascites, nausea, vomiting, and seizure, each occurring in 2 patients (0.2%). CONCLUSIONS ONC028 provides expanded access to ONC201 treatment for patients with previously treated H3 K27M-mutant glioma who are ineligible for enrollment in ongoing trials of ONC201. ONC201 treatment remains well-tolerated.

CTNI-48. A PHASE 1 STUDY OF ERAS-801, A POTENT, SELECTIVE, AND CENTRAL NERVOUS SYSTEM (CNS)-PENETRANT EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) INHIBITOR, FOR PATIENTS WITH RECURRENT GLIOBLASTOMA MULTIFORME (GBM)

Abstract EGFR is among the most common targets for genetic alterations in GBM. Changes in EGFR gene amplification and the extracellular domain result in receptor overexpression or constitutive activation, and enhanced oncogenic signaling. ERAS-801 is a potent, selective, and highly CNS-penetrant EGFR inhibitor being developed for the treatment of GBM, with a focus on tumors harboring EGFR genetic alterations. THUNDERBBOLT-1 is the first-in-human phase 1 dose escalation and expansion trial evaluating ERAS-801 monotherapy for patients with recurrent GBM. ERAS-801 is administered orally once daily for continuous 28-day cycles. As of April 10, 2024, a total of 52 patients were treated across 7 dose cohorts: 20 mg (n=3), 40 mg (n=5), 80 mg (n=3), 160 mg (n=6), 240 mg (n=25), 280 mg (n=4), or 320 mg (n=6). Key patient characteristics were median age of 60 years, 67% male, mostly one prior therapy, and 81% tumors with alterations. The MTD was 240 mg. Dose-limiting toxicities were observed at 320 mg (n=2, Grade 2 QT prolongation, Grade 3 rash and Grade 3 dermatitis acneiform), 280 mg (n=3, Grade 3 QT prolongation), and 240 mg (n=1, Grade 3 QT prolongation) doses. The most common treatment related adverse events (TRAEs), in >10% of patients, were dermatitis acneiform, diarrhea, and nausea. Electrocardiogram QT prolongation occurred in 11.5% of patients and was not associated with clinical findings. ERAS-801 showed rapid absorption; peak plasma concentration was generally achieved within 6 hours post dose. PK exposure increased in a dose-dependent manner over the doses evaluated. Across all doses there was a confirmed partial response (using mRANO) in 1 patient and 6 patients achieved a PFS of 6 months. ERAS-801 shows well behaved PK with substantial CNS penetration, preliminary safety, and tolerability in patients with recurrent GBM. The TRAEs were reversible, manageable, and consistent with known toxicities of EGFR inhibitors.

ReNeu: A Pivotal, Phase IIb Trial of Mirdametinib in Adults and Children With Symptomatic Neurofibromatosis Type 1-Associated Plexiform Neurofibroma.

Pharmacologic therapies for neurofibromatosis type 1-associated plexiform neurofibromas (NF1-PNs) are limited; currently, none are US Food and Drug Administration-approved for adults. ReNeu is an open-label, multicenter, pivotal, phase IIb trial of mirdametinib in 58 adults (≥18 years of age) and 56 children (2 to 17 years of age) with NF1-PN causing significant morbidities. Patients received mirdametinib capsules or tablets for oral suspension (2 mg/m2 twice daily, maximum 4 mg twice daily), regardless of food intake, in 3 weeks on/1 week off 28-day cycles. The primary end point was confirmed objective response rate (ORR; proportion of patients with a ≥20% reduction of target PN volume from baseline on consecutive scans during the 24-cycle treatment phase) assessed by blinded independent central review (BICR) of volumetric magnetic resonance imaging. Twenty-four of 58 adults (41%) and 29 of 56 children (52%) had a BICR-confirmed objective response during the 24-cycle treatment phase; in addition, two adults and one child had confirmed responses during long-term follow-up. Median (range) target PN volumetric best response was -41% (-90 to 13) in adults and -42% (-91 to 48) in children. Both cohorts reported significant and clinically meaningful improvement in patient- or parent proxy-reported outcome measures of worst tumor pain severity, pain interference, and health-related quality of life (HRQOL) that began early and were sustained during treatment. The most commonly reported treatment-related adverse events were dermatitis acneiform, diarrhea, and nausea in adults and dermatitis acneiform, diarrhea, and paronychia in children. In ReNeu, the largest multicenter NF1-PN trial reported to date, mirdametinib treatment demonstrated significant confirmed ORRs by BICR, deep and durable PN volume reductions, and early, sustained, and clinically meaningful improvement in pain and HRQOL. Mirdametinib was well-tolerated in adults and children.

Inhibition of Bruton's tyrosine kinase with PD-1 blockade modulates T cell activation in solid tumors.

BACKGROUNDInhibition of Bruton's tyrosine kinase with ibrutinib blocks the function of myeloid-derived suppressor cells (MDSC). The combination of ibrutinib and nivolumab was tested in patients with metastatic solid tumors.METHODSSixteen patients received ibrutinib 420 mg p.o. daily with nivolumab 240 mg i.v. on days 1 and 15 of a 28-day cycle. The effect of ibrutinib and nivolumab on MDSC, the immune profile, and cytokine levels were measured. Single-cell RNA-Seq and T cell receptor sequencing of immune cells was performed.RESULTSCommon adverse events were fatigue and anorexia. Four patients had partial responses and 4 had stable disease at 3 months (average 6.5 months, range 3.5-14.6). Median overall survival (OS) was 10.8 months. Seven days of Bruton's tyrosine kinase (BTK) inhibition significantly increased the proportion of monocytic-MDSC (M-MDSC) and significantly decreased chemokines associated with MDSC recruitment and accumulation (CCL2, CCL3, CCL4, CCL13). Single-cell RNA-Seq revealed ibrutinib-induced downregulation of genes associated with MDSC-suppressive function (TIMP1, CXCL8, VEGFA, HIF1A), reduced MDSC interactions with exhausted CD8+ T cells, and decreased TCR repertoire diversity. The addition of nivolumab significantly increased circulating NK and CD8+ T cells and increased CD8+ T cell proliferation. Exploratory analyses suggest that MDSC and T cell gene expression and TCR repertoire diversity were differentially affected by BTK inhibition according to patient response.CONCLUSIONIbrutinib and nivolumab were well tolerated and affected MDSC and T cell function in patients with solid metastatic tumors.TRIAL REGISTRATIONClinicalTrials.gov NCT03525925.FUNDINGNIH; National Cancer Institute Cancer; National Center for Advancing Translational Sciences; Pelotonia.

Phase II trial of multi-tyrosine kinase inhibitor ESK981 in combination with PD-1 inhibitor nivolumab in patients with metastatic castration-resistant prostate cancer.

Increasing the response rates of immune checkpoint inhibitors in patients with metastatic castration-resistant prostate cancer (mCRPC) presents a significant challenge. ESK981 is a multi-tyrosine kinase and PIKfyve lipid kinase inhibitor that augments immunotherapeutic responses. In this phase II study, ESK981 was combined with the PD-1 blocking monoclonal antibody nivolumab to test for potentially improved response rates in patients with mCRPC who have progressed on androgen receptor (AR)-targeted agents and chemotherapy. Eligible patients received ESK981 orally once daily for five consecutive days, followed by a two-day break. Patients were also treated with nivolumab intravenously on Day 1 of each 28-day cycle. The primary endpoints were a 50% reduction in prostate-specific antigen (PSA50), and safety. Secondary endpoints included radiographic progression free survival (rPFS) and overall survival (OS). Additional investigations included whole exome sequencing in patients. Ten patients were enrolled. The maximum PSA decline from baseline of 14% was achieved in only one patient. Grade 3 treatment-related adverse events (AEs) included fatigue, anemia, and lymphopenia. There were no Grade 4 events. The median rPFS was 3.7 months (95% CI, 1.6-8.4). The median OS was 9.6 months (95% CI, 1.8-22.4). The study was terminated due to futility after 10 patients. Whole exome sequencing identified AR amplification in 63% of patients (5/8). ESK981 + nivolumab showed no antitumor activity in patients with AR-positive (AR+) mCRPC. Further evaluation of ESK981 combined with the PD-1 inhibitor nivolumab in AR + mCRPC patients is not warranted. (Trial registration: ClinicalTrials.gov NCT04159896. Registration date: November 12, 2019.).

Ultrasound in in vitro fertilization programs

Ultrasound examination is an integral part of in vitro fertilization programs. This work shows that the antral follicle count compared to the level of antimüllerian hormone is a preferred marker for assessing the ovarian reserve, response to ovarian stimulation and the results of in vitro fertilization programs, while counting the antral follicle count can be carried out on any day of the menstrual cycle without reducing the informativeness of the study of the ovarian reserve, which is convenient for both patients and doctors. 3D transvaginal ultrasound allows automated assessment of the number of antral follicles with high accuracy and efficiency in less time than 2D transvaginal ultrasound. Using 3D transvaginal ultrasound and artificial intelligence, a threshold value of dominant follicle volume of 0.5 cm3 or greater was determined as a marker for predicting the number of mature oocytes in in vitro fertilization programs. The measurement of endometrial thickness and volume in combination with the determination of vascularization index, flow index, vascularization-flow index and systole-diastolic ratio in the uterine artery at transvaginal ultrasound allows predicting the results of in vitro fertilization programs. Modern possibilities of transabdominal oocyte aspiration using vaginal probe are presented.

The vector regulation hypothesis: dynamic competition between pathogen and vector behaviors constrains Xylella fastidiosa biofilm development in sharpshooter foreguts.

Xylella fastidiosa (Xf) bacteria form biofilm on the cuticular surfaces of the functional foregut (precibarium and cibarium) of its vectors, xylem fluid-ingesting sharpshooter leafhoppers and spittlebugs. While much is known about Xf biofilm development and maturation in vitro, little is known about these processes in vectors. Real-time (RT)-PCR was used to quantify Xf genomes daily in the functional foreguts of blue-green sharpshooters, Graphocephala atropunctata, over 7 days of exposure to infected grapevines. Scanning electron microscopy (SEM) was used to examine Xf biofilm formation at 4 and 7 days of that time course. PCR showed populations building and reducing over a 4-day cycle. SEM revealed that foreguts at 4 days showed variability in quantity and location of bacterial attachment. Only early-stage biofilm formation occurred in low-turbulence areas of the cibarium, while high-turbulence areas of the cibarium and precibarium had rare but older, more developed macro-colonies. Biofilm was almost absent at 7 days but left behind adhesive material and remnants of prior colonization. Evidence supports the hypothesis that bacterial colonization was repeatedly interrupted and constrained by the vector. Behaviors such as egestion and enzymatic salivation likely can loosen and eject Xf biofilm, perhaps when profuse biofilm interferes with ingestion. Thus, vector acquisition of Xf is a dynamic and stochastic process of interactions between bacteria and insects. We further hypothesize for future testing that the insect can regulate this interaction. A deep understanding of Xf acquisition will aid the ongoing development of grapevine resistance to vector transmission of xylellae diseases.IMPORTANCEXylella fastidiosa (Xf) is one of the most destructive invasive plant pathogens in the world, able to hijack new vectors when it invades a region; yet the temporal interplay of bacterial colonization and insect behavior is unknown. This paper describes important findings about the process of Xf biofilm formation and maturation in a vector, contrasting similarities and differences with such formation in vitro. Results support the hypothesis that the behavior of the vector constrains and may regulate Xf biofilm formation, in dynamic competition with the bacterium. The data from this paper partly explain why Xf is so successful at invasion. Because the bacterium can be acquired and inoculated very quickly, it can move readily from old to new vectors and host plants in all-new environments. Our findings are relevant to biosecurity decisions because they demonstrate the importance of identifying potential vector species in the Xylella invasion front.

Phase II trial evaluating the long-term efficacy and peripheral sensory neuropathy of capecitabine plus oxaliplatin (XELOX) as adjuvant therapy in Japanese patients with operated stage III colon cancer

Adjuvant oxaliplatin plus capecitabine (XELOX) therapy is recommended for patients with curatively resected colon cancer. However, prospective data on its practical application in Japanese patients are limited. Therefore, we aimed to conduct a long-term clinical evaluation of the efficacy and safety of adjuvant XELOX in patients with curatively resected stage III colon cancer (MCSCO-1024). This prospective, multi-center, open-label, single-arm, phase II study enrolled patients with curatively resected stage III colon cancer. The treatment protocol consisted of a 120-minute intravenous infusion of oxaliplatin (130 mg/m2) on day 1 and two divided doses oral capecitabine (2000 mg/m2/day) for 14 days in a 3-week cycle, totaling eight cycles (24 weeks). The primary endpoint was 3-year disease-free survival (DFS), and the secondary endpoints were 5-year overall survival and long-term prognosis of peripheral sensory neuropathy. A total of 196 patients were enrolled between November 2011 and August 2014 (34 months). The 3-year DFS rate was 73%, and the 5-year overall survival rate was 87%. The overall incidence of peripheral sensory neuropathy was 17%, with a 1% rate of grade 3 neuropathy after 5 years. Adjuvant XELOX demonstrated utility and safety in the clinical management of Japanese patients with stage III colon cancer.

Circulating tumor DNA status and dynamics predict recurrence in patients with resected extrahepatic cholangiocarcinoma

Background & AimsSurgery is the only curative therapeutic option for resectable extrahepatic cholangiocarcinoma (eCCA), but recurrence is common, and prognosis is poor. There is an unmet clinical need for improved decision-making regarding adjuvant chemotherapy (ACT). Here we evaluated the usefulness of monitoring longitudinal circulating tumor DNA (ctDNA) for minimal residual disease (MRD) in patients of the STAMP trial, which compares the efficacy of adjuvant capecitabine (CAP) versus gemcitabine plus cisplatin (GemCis). MethodsBetween July 2017 and November 2020, 101 patients were randomized 1:1 to receive GemCis (n=50) or CAP (n=51). Efficacy outcomes were analyzed with an extended follow-up of 19 months from the previous report. From a biomarker cohort of 89 patients, longitudinal plasma samples (n=254) were prospectively collected post-surgery before adjuvant chemotherapy (ACT), and on-ACT at 12 and 24 weeks from cycle 1 day 1 (C1D1). ctDNA was evaluated using a personalized, tumor-informed, 16-plex PCR-NGS assay and was correlated with clinical outcomes. ResultsIn the extended follow-up analysis, median disease-free survival (DFS) and overall survival (OS) did not significantly differ between the CAP and GemCis groups. Significantly inferior DFS was associated with ctDNA-positivity before ACT (HR, 1.8; p=0.029), on-ACT at 12 weeks from C1D1 (HR, 7.72; p<0.001), on-ACT at 24 weeks from C1D1 (HR, 5.24; p<0.001), and anytime post-surgery (HR, 3.81; p<0.001). Analysis of pre-treatment to on-treatment ctDNA dynamics revealed that serially ctDNA-negative patients exhibited a significantly longer DFS compared to those with sustained ctDNA-positivity (HR, 6.7; p<0.001) or who turned ctDNA-positive (HR, 5.8; p<0.001). ConclusionIn patients with resected eCCA, ctDNA status and dynamics predicted recurrence during adjuvant therapy, and may help optimize clinical decision-making. Impact and implicationsThe findings from this study highlight the critical role of ctDNA as a prognostic biomarker and monitoring tool for patients with resected extrahepatic cholangiocarcinoma (eCCA). By demonstrating the superiority of ctDNA to predict disease recurrence compared to conventional biomarkers such as CA 19-9 and CEA, this study underscores its potential in guiding decision-making during adjuvant chemotherapy. These results may be crucial to refine post-surgical treatment strategies and improve patient outcomes. The practical application of ctDNA monitoring could lead to more personalized treatment approaches, enabling timely interventions based on minimal residual disease (MRD) status. Clinical Trial Registration numberNCT03079427