Citations

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).

Abstract Genomic alterations and molecular subgroups between extracranial disease sites and brain metastases often differ, yet the prevalence and clinical significance of divergent evolution in brain metastases is not fully understood. This study examined genomic alterations and molecular subgroup divergence rates between matched brain metastases and extracranial disease sites. A retrospective, two-center study was conducted on patients who underwent resection of brain metastases between 2014-2022 with clinical and matched genomic data and/or molecular markers available. The overall cohort comprised 256 patients with matched tumors from multiple cancer types, most commonly from breast (n=108, 42.2%), melanoma (n=83, 32.4%), and NSCLC (n=43, 16.8%). Targeted next-generation sequencing of over 500 oncogenes was performed on resected tumors as part of clinical care (n=41 patients with matched specimens). Molecular subgroups for breast, melanoma, and non-small cell lung cancer were also assessed by immunohistochemistry to evaluate rates of molecular subgroup discordance between sites. Subgroup discordance by immunohistochemistry was observed most frequently across breast cancer (22.2%, n=24/108) with loss of the estrogen receptor (ER) and progesterone receptor (PR) and gain of HER2 most frequently observed within brain metastases. Molecular subgroup discordance was rare within melanoma (7.3%, n=6/82) and NSCLC (14.0%, n=6/43) patients. When evaluating oncogenomic alterations from targeted DNA sequencing in 41 patients with matched specimens, 80.5% (33/41) of brain metastases demonstrated a unique oncogene alteration profile compared to an extracranial disease site. Fourteen patients (34.1%) had a gain of at least 1 targetable alteration within a brain metastasis that was not observed in an extracranial disease site. Brain metastases demonstrated high rates of genomic divergence compared to primary and extracranial metastatic disease sites. This data supports obtaining brain metastasis tissue and conducting molecular profiling of this tissue to help select optimal CNS penetrant systemic therapies for each patient.

Abstract Heterozygous H3.3 K27M mutations are central to the pathogenesis of diffuse midline gliomas (DMG), causing a global reduction in H3K27 trimethylation (H3K27me3) and subsequent epigenetic dysregulation. H3.3 contains a unique Serine 31 (S31) phosphorylation site crucial for mitotic checkpoint regulation. In DMG cells, reduced mitotic S31 phosphorylation correlates with chromosomal instability and aneuploidy. Using a mouse model, we demonstrate that both H3.3K27M and H3.3S31A mutations promote high-grade glioma development, whereas wild-type H3.3 does not. Importantly, S31A, which maintains normal K27me, suggests that S31 phosphorylation loss alone is oncogenic. The H3.3K27M mutation disrupts epigenetic regulation by inhibiting the Polycomb Repressive Complex 2 (PRC2), leading to decreased H3K27me3 and unintended gene induction. Concurrently, K27M exerts a compensatory repressive effect on the transcriptome, mediated by reduced S31 phosphorylation, independent of PRC2 activity. Using CRISPR-engineered isogenic DMG cells and analyzing the transcriptome and chromatin accessibility with RNA-seq and ATAC-seq, we found that the K27M mutation produces a balanced gene expression profile, while PRC2 loss primarily leads to gene induction. Notably, cells with S31A mutations also maintain this balanced profile, linking the PRC2-independent effect of K27M to reduced S31 phosphorylation. Conversely, cells with wild-type K27 but S31A mutation show a repressive genomic state, evidenced by an up/down gene ratio of 0.75, owing to functional PRC2. We further show that the genes uniquely dysregulated by K27M or S31A, independent of PRC2, overlap significantly, with dysregulated genes displaying altered chromatin accessibility. This suggests that the effect of K27M and S31A mutations on gene regulation is primarily due to changes in chromatin state. This complex interplay points to targeting K27M-associated pathways, particularly S31 phosphorylation, as a promising therapeutic avenue in DMG, a malignancy with fewer effective treatments and dismal prognosis.

Abstract Current standard of care for IDH-wildtype glioblastoma (GBM) includes maximal safe resection, adjuvant radiation, and chemotherapy with the alkylating agent temozolomide. A subset of gliomas treated with temozolomide develop somatic hypermutation with a predominance of C>T transitions due to the alkylation effects on DNA. However, the frequency of occurrence, clinical ramifications, and predictive biomarkers for developing temozolomide-induced hypermutation (TMZ-HM) in GBM are unknown. Here we performed comprehensive histopathologic, genomic, and epigenomic evaluation of paired initial and recurrent GBM from 106 patients. Seven patients (7%) developed hypermutation at time of first recurrence, while an additional five patients (5%) developed hypermutation at a subsequent recurrence. Patients who developed TMZ-HM had a significantly longer interval between initial surgery and first recurrence (27.8 vs. 9.9 months, p<0.001). In contrast to IDH-mutant gliomas where TMZ-HM is associated with poor prognosis, those patients with IDH-wildtype GBM who developed TMZ-HM had significantly longer overall survival from both initial surgery (67.9 vs. 20.3 months, p<0.001) and from time of recurrence after development of hypermutation (30.9 vs. 9.5 months, p=0.001). There was no difference in oncogenic alteration frequency in initial GBM that subsequently developed TMZ-HM. However, 4 specific CpG sites out of 12 total interrogated sites in the promoter region of MGMT (a DNA repair enzyme) and 5 specific CpG sites in the promoter region of KCNQ1DN (a negative regulator of c-Myc) were significantly more hypermethylated in those GBM that developed TMZ-HM. We then generated a weighted risk score across these CpG sites that can be used to prospectively identify GBM likely to develop TMZ-HM associated with favorable survival. In summary, patients with GBM that develop TMZ-HM follow a more favorable clinical course, and specific MGMT and KCNQ1DN promoter hypermethylation patterns could serve as a biomarker to identify these patients who may potentially benefit from extended alkylating chemotherapy treatment.

Summary: The number of spinal reconstruction cases is growing, as are the accompanying complications. Wound complications after spinal reconstruction can be fatal and can affect up to 19% of patients undergoing major spine surgery. The discipline of spinoplastic surgery is characterized by the use of vascularized bone grafts to reconstruct spinal defects, which provide better results compared with nonvascularized and allogenic equivalents, owing to their superior blood supply. We present a 49-year-old man with spinal defect in the C3-C7 region treated with spinoplastic reconstruction. A 5 × 6 cm occipital VBG was designed with a centrally located muscular pedicle and successfully inset into the osseous defect. Radiographs taken 15 months postoperatively demonstrated overall excellent bony fusion, and the patient made an appropriate clinical recovery. In difficult spine procedures, the use of this occipital vascularized bone graft may lead to higher fusion rates without the need for free tissue transfer or allograft placement, which may not be available at all surgical centers around the world.

Background: Etrasimod is an oral, once-daily (QD), selective sphingosine 1-phosphate (S1P)1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis (UC). It is known that non-serious treatment-emergent adverse events (TEAEs) may not lead to UC drug discontinuation but can affect treatment tolerability. Objectives: This post hoc analysis evaluated the incidence of specific, common, non-serious TEAEs reported in the etrasimod UC clinical programme and the characteristics of affected patients. Design: Data included patients from the Placebo-controlled UC cohort (phase II OASIS, and phase III ELEVATE UC 52 and ELEVATE UC 12 trials) receiving QD etrasimod (2 or 1 mg) or placebo. Methods: Proportions and incidence rates (IRs; the number of patients with a TEAE divided by the total exposure in patient-years (PYs), per 100 PY) of Headache, Pyrexia, Nausea and Dizziness TEAEs were reported. Changes in heart rate among patients with Dizziness TEAEs were also evaluated. Results: Among 943 patients (etrasimod 2 mg, N = 577 (276.7 PY); etrasimod 1 mg, N = 52 (11.4 PY); placebo, N = 314 (115.1 PY)), 48, 34, 27 and 21 patients experienced events of Headache, Pyrexia, Nausea and Dizziness, respectively. All events were non-serious; one patient treated with etrasimod was discontinued due to a Pyrexia TEAE. Numerically, IRs of Headache and Dizziness TEAEs were higher, and Nausea slightly higher, with etrasimod versus placebo (13.45 vs 8.63 per 100 PY, 6.52 vs 1.69 and 7.18 vs 5.13 per 100 PY, respectively); IRs were similar for Pyrexia. The duration of most TEAEs was 1–10 days. Conclusion: In the etrasimod UC clinical programme, all Headache, Pyrexia, Nausea and Dizziness events were non-serious. Headache and Dizziness were more frequent, and Nausea slightly more frequent, among patients receiving etrasimod versus placebo. The post hoc nature of this analysis is a limitation. These results reiterate the favourable safety profile and tolerability of etrasimod. Trial registration: ClinicalTrials.gov: NCT02447302; NCT03945188; NCT03996369.

Abstract Background and Aims Patients with inflammatory bowel disease (IBD) have a higher risk of developing colorectal dysplasia and colorectal cancer compared to the general population. Although the use of surveillance protocols has improved the ability to detect dysplasia, some lesions are still missed at colonoscopy. This study aims to determine the rate of dysplastic lesions that are undetected at colonoscopies in IBD patients undergoing colectomy and to identify factors associated with missed dysplasia. Methods Patients who had received a total or subtotal colectomy at Mayo Clinic (Rochester, Minnesota), between January 2003 and December 2022, and had a complete colonoscopy within 5 years before surgery were retrospectively enrolled. Data abstracted included demographic information, disease-related data, colonoscopy and pathology reports, and surgery pathology reports. Colonoscopy and surgery findings were compared, and patients were divided into 3 groups: no dysplasia at both, detected dysplasia, and undetected dysplasia. Results Among 1320 IBD patients undergoing colectomy, 5.4% had undetected dysplastic lesions identified only at surgery. Factors independently associated with dysplasia detection were endoscopic remission or mild endoscopic disease activity (odds ratio [OR], 2.326; P = .0081; 95% CI, 1.246-4.342), prior dysplasia detection (OR, 1.876; P = .0491; 95% CI, 1.002-3.511), colonoscopy performed for surveillance (OR, 2.380; P = .0048; 95% CI, 1.302-4.350), and longer disease duration at surgery (OR, 1.039; P = .0085; 95% CI, 1.010-1.070). Conclusions Clinicians should be aware of the risk of missing dysplastic lesions, especially when endoscopic disease activity is moderate/severe, and not only for longstanding disease. Efforts should be made to obtain endoscopic remission to make the “invisible” visible.

Objective Dermoid cyst (DC) is a congenital cyst with the potential to have intracranial extension (ICE). This study aims to evaluate the imaging yield and surgical outcomes of nasal, medial brow, forehead, and scalp DCs. Design Retrospective review of craniofacial DCs treated at our institution between 1992 and 2024. Results A total of 117 patients (57 females) were included. The median age at cyst detection and removal were 4.8 months (IQR 3.6-9.6) and 1.8 years (IQR 0.9-5.3), respectively. In 42 patients, parents have noticed the presence of the cyst immediately after birth. Cyst wall rupture during surgical removal was reported in 15.4%. The median follow-up time was 1.3 months (IQR 0.5-12.2). Three patients experienced recurrence. No postoperative complication was reported. The regions with the highest prevalence of ICE were the forehead, frontotemporal scalp, and nasal region. The lateral frontal/temporal scalp had a 33.3% rate of ICE. Midline forehead/scalp lesions demonstrated a higher risk of ICE compared to their lateral equivalents (54.5% vs 17.5%, P = .03). The sensitivity and specificity of magnetic resonance imaging (MRI) were 100% and 95.7%, while for computed tomography (CT scans) were 72.7% and 96.5%. The Area Under the Curve for MRI was 0.978, and for CT was 0.846. The sensitivity and specificity of ultrasound were 50% and 100%. Conclusions Midline forehead/scalp DCs are more prone to extend intracranially than lateral DCs. MRI had a higher sensitivity and specificity than CT scans in detecting ICE. Routine screening imaging should be considered in midline forehead/scalp, lateral frontal/temporal, and nasal DCs.