Abstract Brain metastases (BM) are a leading cause of cancer death and prognosis remains poor despite treatment advances at other sites. Models are central to therapeutic development, but few orthotopic patient-derived xenograft (PDX) models of BM exist. To represent diversity across BM types, we established a program to create orthotopic PDX at scale from all BM patients. To date BM were received from 100 patients and PDX attempted by direct brain injection (PDX, n=89) or injection of low passage patient-derived cell lines (PDCLX, n=11). We created 65 successful BM PDX from 13 cancers: 17 lung (55% take), 15 breast (68%), 6 melanoma (75%), 5 CNS lymphoma (83%), 3 gastrointestinal (75%), 2 esophageal (40%), 2 ovarian (67%), 1 sarcoma (100%), 1 laryngeal (100%), 1 prostate (100%), 1 pancreatic (100%), 1 uterine adenosarcoma (100%), and 1 yolk sac tumor (100%). Take rate was similar for models derived from patients with prior chemotherapy-only versus immune/targeted therapy-only (63 vs 58%). Fifteen patients had live tumor and matching PBMCs archived for modeling in vitro immunotherapy responses. Mean time to moribund among different cancer types ranged from 27 days (yolk sac tumor) to 177.5 days (ovarian). BM PDX had a favorable timeline for preclinical study (90% moribund at 180 days). All PDX retained high fidelity to the patient driver SNVs and copy aberrations, even at >P4. No significant differences noted by immunodeficient strain (SCID versus NSG) or injection site (orthotopic versus heterotopic). Explants from BM PDX were able to generate long-term cell lines (60%) or short-term cultures with qualitative concordance of model-to-patient responses to targeted therapy (Osimertinib, EGFRi) and immunotherapy (Pembrolizumab, PD1i). Genomic and clinical data were used to create the DFCI BM PDX cBioPortal for public release and models distribution will be available through the DFCI Center for Patient Derived Models.
<div>Abstract<p>Purpose: We evaluated the efficacy of bavituximab – a monoclonal antibody with anti-angiogenic and immunomodulatory properties – in newly diagnosed glioblastoma (GBM) patients who also received radiation and temozolomide. Perfusion MRI and myeloid-related gene transcription and inflammatory infiltrates in pre-and post-treatment tumor specimens were studied to evaluate on-target effects (NCT03139916). Patients and Methods: Thirty-three adults with <i>isocitrate-dehydrogenase</i>-wild-type GBM received 6 weeks of concurrent chemoradiation, followed by 6 cycles of temozolomide (C1-C6). Bavituximab was given weekly, starting week 1 of chemoradiation, for at least 18 weeks. The primary endpoint was proportion of patients alive at 12 months (OS-12). The null hypothesis would be rejected if OS-12 was ≥72%. Relative cerebral blood flow (rCBF) and vascular permeability (Ktrans) were calculated from perfusion MRIs. Peripheral blood mononuclear cells (PBMCs) and tumor tissue were analyzed pre-treatment and at disease progression using RNA transcriptomics and multispectral immunofluorescence for myeloid-derived suppressor cells (MDSCs) and macrophages. Results: The study met its primary endpoint with an OS-12 of 73% (95% CI 59-90%). Decreased pre-C1 rCBF (HR 4.63, p=0.029) and increased pre-C1 Ktrans were associated with improved OS (HR 0.09, p=0.005). Pre-treatment, overexpression of myeloid-related genes in tumor tissue was associated with longer survival. Post-treatment, tumor specimens contained fewer immunosuppressive MDSCs (p=0.01). Discussion: Bavituximab has activity in newly diagnosed GBM and resulted in on-target depletion of intratumoral immunosuppressive MDSCs. Elevated pre-treatment expression of myeloid-related transcripts in GBM may predict response to bavituximab.</p></div>
Melanoma is the third most common systemic cancer that leads to brain metastases. The annual incidence of melanoma has increased over time, with brain metastases developing in 40% to 50% of patients with advanced melanoma. Traditional management of melanoma-related brain metastases has focused on symptom control as a result of the significant neurologic morbidity associated with the disease. Median overall survival for these patients, if untreated, is approximately 3 months. As with other brain metastases, a multidisciplinary treatment approach that includes surgery and radiation therapy is typically used, with historically little role for systemic, cytotoxic therapy. During the past decade, advancement within the field of genomics has led to the identification of melanoma-specific mutations, namely, v-Raf murine sarcoma viral oncogene homolog B and neuroblastoma RAS viral oncogene homolog, as well as to the development of agents that target these driver mutations. In addition, the advent of immunotherapies, specifically, agents that target cytotoxic T-lymphocyte antigen-4, anti-programmed death-1, and programmed death ligand-1, has increased the potential therapeutic options available to patients with both systemic and brain disease. With these advances, early trials have demonstrated improved overall survival in patients with brain metastases who receive these therapies either as single agents or as part of multimodality treatment regimens.
Abstract 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.
Abstract BACKGROUND The Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) is a phase II platform trial with Bayesian adaptive randomization and deep genomic profiling to more efficiently test experimental agents in newly diagnosed glioblastoma and to prioritize therapies for late-stage testing. METHODS In the ongoing INSIGhT trial, patients with newly diagnosed MGMT-unmethylated glioblastoma are randomized to the control arm or one of three experimental therapy arms (CC-115, abemaciclib, and neratinib). The control arm therapy is radiotherapy with concomitant and adjuvant temozolomide, and primary endpoint is overall survival. Randomization has been adapted based on Bayesian estimation of biomarker-specific probability of treatment impact on progression-free survival (PFS). All tumors undergo detailed molecular sequencing, and this is facilitated with the companion ALLELE protocol. To evaluate feasibility of this approach, we assessed the status of this ongoing trial. RESULTS Since INSIGhT was activated 4.3 years ago, it has expanded to include 12 sites across the United States. A total of 247 patients have been enrolled. Randomization probabilities have been repeatedly adjusted over time based upon early PFS results to alter the randomization ratio from standard 1:1:1:1 randomization. All three arms have completed accrual and efficacy estimates are available based upon comparison to the common control arm in context of relevant biomarkers. There are 87 patients alive and in follow-up, and there are ongoing plans to add additional arms to evaluate further treatments in the future. CONCLUSION The INSIGhT trial demonstrates that a multi-center Bayesian adaptive platform trial is a feasible and effective approach to help prioritize therapies and biomarkers for newly diagnosed GBM. The trial has maintained robust accrual, and the simultaneous testing of multiple agents, sharing a common control arm and adaptive randomization serve as features to increase trial efficiency relative to traditional clinical trial designs.
Leptomeningeal disease (LMD) is a devastating complication of solid tumor malignancies, with dire prognosis and no effective systemic treatment options. Over the past decade, the incidence of LMD has steadily increased due to therapeutics that have extended the survival of cancer patients, highlighting the need for new interventions. To examine the efficacy of immune checkpoint inhibitors (ICI) in patients with LMD, we completed two phase II clinical trials. Here, we investigate the cellular and molecular features underpinning observed patient trajectories in these trials by applying single-cell RNA and cell-free DNA profiling to longitudinal cerebrospinal fluid (CSF) draws from enrolled patients. We recover immune and malignant cell types in the CSF, characterize cell behavior changes following ICI, and identify genomic features associated with relevant clinical phenomena. Overall, our study describes the liquid LMD tumor microenvironment prior to and following ICI treatment and demonstrates clinical utility of cell-free and single-cell genomic measurements for LMD research.
Abstract Despite major strides in cancer research, care, and therapy, these advances have not been equitable across race and ethnicity. Groups underrepresented in medicine (URM) are more likely to have inadequate preventive screening, increased delays in diagnosis, and poor representation in clinical trials. Notably, Black and Latino Americans represent 29% of the population but only reflect 8% of oncology clinical trial participants. Recent studies have shown that this disparity is also present in neuro-oncology as women, Black, and Latino Americans remain under-accrued in clinical trials. Brain tumor patients already face unique barriers to clinical trial enrollment and completion due to disease-specific conditions–such as impaired motor function, cognition, language deficits, and caregiver dependency–which pose additional difficulties in clinical trial consent, enrollment, and adherence. As part of this collaborative initiative, we evaluated the impact of how a lack of diversity in cancer research is detrimental to scientific discovery and propose interventions focused on improving URM engagement with clinical research. Recommendations include the creation of inclusive trial design at the onset, decreasing barriers to care, expanding trial eligibility, and equitable access to tumor profiling for personalized medical trials. Additionally, setting reasonable metrics and goals for accrual and engagement with patient and community stakeholders will ultimately help to diversify trial participants. Lastly, diversification and inclusion practices within the neuro-oncology workforce, including all personnel involved in clinical research, will help to minimize bias, promote concordant care, and assist with developing sustainable solutions. The diversification of participation in neuro-oncology clinical trials is imperative. The lack of diversity in clinical trials can contribute to improper generalizability of treatment efficacy, resulting in potentially harmful practices. Equitable access and inclusion of URM brain tumor patients will not only enhance research discoveries but will also result in improved patient care for all cancer patients.
