Eudocia Quant Lee’s research while affiliated with Brigham and Women's Hospital and other places

2055 Background: Glioblastoma is the most aggressive primary brain tumor of adults, with patients obtaining limited survival benefit from standard-of-care therapies. We are conducting a phase 2, surgical window-of-opportunity study evaluating the combination of pembrolizumab (anti-PD-1 immunotherapy), olaparib (PARP inhibitor), and temozolomide (alkylating chemotherapy) in patients with progressive glioblastoma. Olaparib and temozolomide have the potential of synergistically enhancing the tumor’s susceptibility to immune checkpoint immunotherapy through DNA damage and activation of immune pathways, potentially amplifying the efficacy of pembrolizumab. We provide a preliminary report on the safety and tolerability of the olaparib, temozolomide, and pembrolizumab combination. Methods: We enrolled patients with radiographically progressive glioblastoma, IDH-wildtype, MGMT promoter unmethylated, on 2mg daily or less of dexamethasone. Patients participating in the safety lead-in (Cohort 1) did not require surgically-resectable disease, while those enrolled in the surgical arm (Cohort 2) did. Treatment is provided in consecutive 42-day cycles with olaparib 200mg BID and temozolomide 50mg QD given on days 1-7 and 22-29, and pembrolizumab 400mg IV given on day 1. Adverse events (AEs), dose-limiting toxicities (DLTs), and high-frequency toxicities (≥50% occurrence) were assessed, along with dose modifications or delays required to manage treatment-related toxicities. AEs were graded according to CTCAE v5.0 criteria, with pre-specified measures to address reversible toxicities through dose adjustments. Results: Six patients were enrolled in the safety lead-in (Cohort 1), which followed a 3+3 design. Grade 1–2 leukopenia, lymphopenia, and neutropenia were observed in 3 patients and resolved without intervention. Grade 4 neutropenia was observed in two patients (starting in cycle 2 for one patient, and on cycle 5 for the other). This resolved with dose delays, reduction in temozolomide dose or discontinuation of temozolomide (1 patient). In Cohort 2, which is ongoing (25 patients currently enrolled), toxicity profiles remain consistent with those observed in Cohort 1 patients. Grade 4 neutropenia has been observed in 1 (6%) of the enrolled patients, improving with dose delays and temozolomide dose reduction. Conclusions: The combination of olaparib, temozolomide, and pembrolizumab demonstrates a tolerable safety profile in patients with progressive glioblastoma. Observed hematologic toxicities are reversible with appropriate management, supporting the ongoing evaluation of this regimen to assess its efficacy and therapeutic potential. Clinical trial information: NCT05463848 .

Since its first activities in 2008 and 2009, the Response Assessment in NeuroOncology (RANO) group has given guidance on response assessment, trial design and trial procedures in order to improve and standardize the way clinical trials in neurooncological studies are performed. To achieve its objectives, a variety of working groups have been initiated that cover many aspects of clinical trial design and outcome assessment in patients with tumors affecting the Central Nervous System. The RANO working groups are built on expertise without a formal structure, which makes rapid responses to new developments possible. RANO is aiming at evidence based guidelines and recommendations, but in the absence of evidence will provide consensus based guidance achieved by inviting recognized international experts. In its 15 year of existence, more than 60 RANO papers have been published mostly in high ranking journals, and its recommendations have been accepted by regulators and industry as guiding principes. RANO organizes two meetings per year, one in conjunction with the annual American Society for Clinical Oncology (ASCO) meeting, and one during the annual Society for Neuro-Oncology meeting. These meetings are open, as are the working groups of RANO. New initiatives are welcomed.

Inhibitors of murine double minute homolog 2 (MDM2) represent a promising therapeutic approach for the treatment of TP53 wild-type glioblastomas (GBMs), reactivating p53 signaling to induce cancer cell death. We conducted a surgical window-of-opportunity trial (NCT03107780) of the MDM2 inhibitor navtemadlin (KRT-232) in 21 patients with TP53 wild-type recurrent GBM to determine achievable drug concentrations within tumor tissues and biological mechanisms of response and resistance. Participants received navtemadlin at 120 mg ( n = 10) or 240 mg ( n = 11) for 2 days before surgical resection and after surgery until progression or unacceptable toxicity. Both 120 and 240 mg daily dosing achieved a pharmacodynamic impact, but median progression-free survival was 3.1 months. DNA sequencing of three recurrent tumors revealed an absence of TP53 -inactivating mutations, indicating alternative mechanisms of resistance. To understand the mechanisms of response and resistance associated with navtemadlin, we conducted functional and spatial analyses of human tissue and patient-derived GBM neurosphere models. Navtemadlin induced partial tumor cell death as monotherapy, and combination with temozolomide enhanced apoptosis in GBM neurospheres while sparing normal bone marrow cells in vitro. We also observed up-regulation of oligodendrocyte differentiation genes with navtemadlin treatment and enrichment of oligodendrocyte transcription factor 2 (OLIG2)–positive cells at relapse, suggesting an unexplored mechanism of navtemadlin tolerance in GBM. Overall, these results indicated that clinically achievable doses of navtemadlin exert pharmacodynamic effects on GBM and suggest that combined treatment with temozolomide may be a route to more durable survival benefits.

Purpose Adavosertib is an oral small-molecule inhibitor of Wee1. The Adult Brain Tumor Consortium conducted a phase I study evaluating adavosertib in combination with radiation (RT) and temozolomide (TMZ) in patients with newly diagnosed glioblastoma (GBM), as well as a surgical window-of-opportunity study in recurrent GBM. Patients and Methods The MTD of adavosertib was determined in adult patients with newly diagnosed GBM using a standard 3+3 design in two separate cohorts: with concurrent RT/TMZ or with adjuvant TMZ. A combination cohort with both concurrent and adjuvant adavosertib at MTD followed. We also performed intratumoral drug distribution studies in patients with recurrent GBM undergoing surgery. Results As separate cohorts, the MTD for concurrent adavosertib with RT/TMZ was 200 mg daily Monday through Friday × 6 weeks during RT, and the MTD for adjuvant adavosertib with TMZ was 425 mg daily for 5 days of each 28-day cycle. However, six of 12 patients experienced dose-limiting toxicities (DLT) in the combination cohort. The mean ratios of the intratumoral to plasma concentration of adavosertib were 4.18 ± 3.36 for contrast-enhancing tissue and 0.74 ± 0.63 in nonenhancing tissue. Conclusions Adavosertib at 200 mg daily Monday through Friday × 6 weeks with RT/TMZ and at 425 mg daily on a 5-day/28-day cycle with TMZ had an unacceptable DLT rate. Additional dose levels in combination cohorts resulted in DLT, and we deemed concurrent adavosertib too toxic for further examination. Adavosertib 425 mg daily on a 5-day/28-day cycle with adjuvant TMZ is the recommended phase II dosage. Tissue pharmacokinetics in tissue homogenates and by microdialysis provided complementary information about drug penetration.

Glioblastoma is immunologically “cold” and resistant to single-agent immune-checkpoint inhibitors (ICI). Our previous study of neoadjuvant pembrolizumab in surgically-accessible recurrent glioblastoma identified a molecular signature of response to ICI and suggested that neoadjuvant pembrolizumab may improve survival. To increase the power of this observation, we enrolled an additional 25 patients with a primary endpoint of evaluating the cell cycle gene signature associated with neoadjuvant pembrolizumab and performed bulk-RNA seq on resected tumor tissue (NCT02852655). Neoadjuvant pembrolizumab was associated with suppression of cell cycle/cancer proliferation genes and upregulation of T-cell/interferon-related gene expression. This signature was unique to patients treated with neoadjuvant pembrolizumab and was an independent positive risk factor for survival. Our results demonstrate a clear pharmacodynamic effect of anti-PD1 therapy in glioblastoma and identify pathways that may mediate resistance. However, we did not confirm a survival benefit to neoadjuvant pembrolizumab in recurrent glioblastoma and our secondary endpoint of PFS-6 was 19.5% (95% CI: 9.29-41.2%) for the pooled neoadjuvant cohorts. Our new data suggests some patients may exhibit innate resistance to pre-surgical ICI and require other concomitant therapies to sensitize effectively.

Background Mutant isocitrate dehydrogenase (IDHm) inhibitors represent a novel targeted approach for treating IDHm glioma patients, yet their optimal use in clinical practice outside of clinical trials remains undefined. This study describes real-world utilization of the mutant IDH1 inhibitor (IDHi), ivosidenib, in patients with IDHm glioma. Methods We retrospectively reviewed clinical and radiographic data from patients with IDHm glioma treated with ivosidenib monotherapy from 2020-2024 at the Dana-Farber Cancer Institute and Massachusetts General Hospital. Results This cohort included 74 patients with median age of 39. There were 35 astrocytomas and 39 oligodendrogliomas, with 49, 23, and 2, grade 2, 3, and 4 tumors, respectively. Nineteen patients (26%) experienced an adverse event, although only 1 patient discontinued ivosidenib for adverse events. Median progression free survival (PFS) was 31 months and median overall survival (OS) was not reached. Seven patients (9%) had partial response (PR), 3 (4%) had minor response (MR), 47 (64% ) had stable disease (SD), and 17 (23%) had progressive disease (PD). Presence of enhancing disease at ivosidenib initiation was associated with lower disease control rates (DCR) whereas DCR differences were not detected based on grade (grade 2 vs. 3), tumor histology, or age. Subsequent-line ivosidenib use had lower DCR although this may have been explained by enrichment of patients with enhancing disease. Conclusions In this large cohort of IDHm glioma patients, ivosidenib was well-tolerated. Our results support the use of IDHi therapy in patients with grade 2 or 3 astrocytoma or oligodendroglioma and highlight limited effectiveness in patients with enhancing disease.

BACKGROUND Astrocytoma, IDH-mutant, WHO grade 4, are classified as a separate entity in the 2021 WHO classification of central nervous system tumors and have been poorly characterized in the literature. In this study, we report on the clinical outcomes in a large cohort of newly diagnosed grade 4 IDH-mutant astrocytoma. METHODS We retrospectively identified adult patients with astrocytoma, IDH-mutant, WHO grade 4, treated for their initial diagnosis at Dana-Farber Cancer Institute and Massachusetts General Hospital between 2010 and 2021. Clinical, molecular, and radiological characteristics were recorded, and their association with overall survival (OS) and progression-free survival (PFS) was measured by a log-rank test. If a proportional hazard assumption was violated, we compared the median OS and PFS between groups by the bootstrap method instead. RESULTS We identified 140 patients, with a median age at diagnosis of 37.9 years (range: 19-87) and male predominance (60.7%). MGMT promoter was methylated in 51.4%, and CDKN2A/B homozygous deletion was present in 40 cases (28.6%). Most tumors showed enhancement on the preoperative scan (n=108; 77.1%). Seventy percent of patients had subtotal resection, 25.7% had a gross total resection, and 4.3% had a biopsy. Most patients received standard chemoradiation followed by adjuvant temozolomide (n=103; 73.6%). The median OS was 6.9 years (95% CI: 4.5-9.2), and the median PFS was 3.3 years (95% CI: 2.1-4.4). OS and PFS were not associated with MGMT promoter methylation or the presence of enhancement on the preoperative scan. CDKN2A/B homozygous deletion was associated with worse OS (5.5 vs. 7.8 years, log-rank test-based p-value=0.036) but had no association with PFS (3.4 vs 2.6 years, bootstrap method-based p-value=0.488). CONCLUSIONS In our cohort of astrocytoma, IDH-mutant, WHO Grade 4, CDKN2A/B homozygous deletion had a negative prognostic impact, whereas MGMT promoter methylation status and enhancement on the preoperative scan did not affect survival outcomes.

BACKGROUND QBS10072S, is a L-type amino acid transporter 1 (LAT-1) targeted alkylating agent that utilizes LAT1 as both a transport and targeting mechanism. QBS10072S can cross the blood-brain barrier, exhibits potential for cytotoxicity with a mechanism distinct from temozolomide and has low off-target effects. QBS10072S is being evaluated in the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial (NCT02977780), a randomized phase 2 adaptive multi-arm platform trial. METHODS Adult patients with newly diagnosed MGMT-unmethylated glioblastoma are eligible for INSIGhT. Since there is no safety data available for QBS10072S in combination with radiotherapy, a safety lead-in evaluation was conducted utilizing a 3 + 3 design. Starting dose for QBS10072S was 12mg/m2 in combination with radiation therapy and adjuvantly as monotherapy in 28 day cycles. Patients were monitored for dose-limiting toxicities (DLTs) to identify the maximum tolerated dose and recommended phase 2 dose (RP2D). RESULTS Nine patients were enrolled December 2022 to October 2023 for safety lead-in testing, and median age was 57 years (41-67) with 6 (66%) males, 6 (66%) patients with gross total resection, and median KPS 90 (range 80-100). Pharmacokinetic studies indicated that drug exposure was lower than prior studies, and three patients received 12mg/m2, 15mg/m2, and 18mg/m2, respectively, per dose escalation protocol. No DLTs nor adverse events leading to study drug discontinuation were reported during the evaluation period. Four patients had possible treatment-related CTCAE grade ≥ 3 toxicity including lymphopenia (n=3) and fatigue (n=1). The RP2D was determined to be 18mg/m2. Seven patients were discontinued from study treatment due to progressive disease and two patients remain on treatment. CONCLUSION QBS10072S, concurrent and adjuvant to radiation therapy, was well-tolerated in patients with newly diagnosed unmethylated MGMT glioblastoma. QBS10072S 18mg/m2 is being evaluated as a treatment arm in phase 2 testing in the ongoing INSIGhT trial.