In the 1980's, as the importance of matrix metalloproteinases (MMPs) in cancer progression was discovered, it was recognized that in most tumors these proteases were abundantly and sometimes exclusively expressed not by tumor cells, but by normal host-derived cells like fibroblasts, vascular endothelial cells, myofibroblasts, pericytes or inflammatory cells that contribute to the tumor microenvironment. Later experiments in mice deficient in specific MMPs revealed that host-derived MMPs play a critical role not only in tumor cell invasion, but also in carcinogenesis, angiogenesis, vasculogenesis and metastasis. Tumor cells secrete many factors, cytokines and chemokines that directly or indirectly increase the expression of these MMPs in the tumor microenvironment where they exert extracellular matrix (ECM) degrading and sheddase activities. The knowledge of the complex role that stromal-derived MMPs play in the interaction between tumor cells and stromal cells should allow us to consider specific windows in cancer treatment when MMP inhibition could have a valuable therapeutic effect.

BACKGROUND: Although opioids are central to acute pain management, numerous studies have shown that many physicians prescribe them incorrectly, resulting in inadequate pain management and side effects. We assessed whether a case-based palliative medicine curriculum could improve medical house staff opioid prescribing practices.

10009 Background: Entrectinib is a CNS-penetrant oral inhibitor of TrkA/B/C, ROS1 and ALK tyrosine kinases. We report the efficacy of entrectinib in children with recurrent/refractory solid or CNS tumors. Methods: Patients ≤ 20y old with recurrent/refractory solid tumors were eligible. After determination of the recommended dose in all-comers, disease-specific expansion cohorts of CNS and solid tumors harboring target aberrations in NTRK1/2/3, ROS1 or ALK, and neuroblastoma (NBL), regardless of mutation spectrum, were enrolled. Response, assessed by Investigator, was classified as complete response (CR), partial response (PR), stable disease (SD) or progressive disease (PD) using RANO for CNS tumors, RECIST for solid tumors, and Curie score for NBL. Results: Between May 2016 and October 2018, 29 patients aged 4.9m–20y (median 7y) were enrolled and 28 were evaluated for response. Entrectinib was well tolerated. Dose limiting toxicities were elevated creatinine, dysgeusia, fatigue and pulmonary edema. The recommended dose was 550 mg/m2 daily. All responses occurred at doses ≥ 400 mg/m2. In CNS tumors (n = 6), all high-grade with gene fusions: 1 achieved a CR ( ETV6-NTRK3); 3 achieved a PR ( TPR-NTRK1, EEF1G-ROS1, EML1-NTRK2); 1 achieved an unconfirmed PR ( GOPC-ROS1); and 1 has yet to be evaluated ( KANK1-NTRK2). In extracranial solid tumors (n = 8), 6 had a fusion of whom 1 achieved a CR ( DCTN1-ALK) and 5 achieved a PR ( TFG1-ROS1, EML4-NTRK3, ETV6-NTRK3, KIF5B-ALK, ETV6-NTRK3). In NBL (n = 15): 1 achieved a CR ( ALK F1174L). Median duration of therapy was 85d (6–592d) for all patients; 56d (6–338d) for non-responders; and 281d (56–592d) for responders. Median time to response was 57d (30–58d). Conclusions: Entrectinib produced striking, rapid and durable responses in all children with refractory CNS and solid tumors harboring NTRK1/2/3, ROS1 or ALK fusions (11 out of 11) as well as in an ALK-mutated NBL. No responses were seen in tumors lacking aberrations in target kinases. These results support the continued evaluation of entrectinib as a targeted therapeutic in solid tumors with NTRK1/2/3, ROS1 and ALK fusions, especially in high-grade CNS neoplasms. Clinical trial information: NCT02650401.

Background Entrectinib is a TRKA/B/C, ROS1, ALK tyrosine kinase inhibitor approved for treatment of adults and children aged ≥12 years with NTRK fusion-positive solid tumors and adults with ROS1 fusion-positive non-small cell lung cancer. We report analysis of the STARTRK-NG trial, investigating the recommended phase 2 dose (RP2D) and activity of entrectinib in pediatric patients with solid tumors including primary central nervous system tumors. Methods STARTRK-NG (NCT02650401) is a phase 1/2 trial. Phase 1, dose escalation of oral, once-daily entrectinib, enrolled patients aged <22 years with solid tumors with/without target NTRK1/2/3, ROS1, or ALK fusions. Phase 2, basket trial at the RP2D, enrolled patients with intracranial or extracranial solid tumors harboring target fusions, or neuroblastoma. Primary endpoints: phase 1, RP2D based on toxicity; phase 2, objective response rate (ORR) in patients harboring target fusions. Safety-evaluable patients: ≥1 dose of entrectinib; response-evaluable patients: measurable/evaluable baseline disease and ≥1 dose at RP2D. Results At data cut-off, 43 patients, median age 7 years, were response-evaluable. In phase 1, four patients experienced dose-limiting toxicities. The most common treatment-related adverse event was weight gain (48.8%). Nine patients experienced bone fractures (20.9%). In patients with fusion-positive tumors, ORR was 57.7% (95% CI 36.9–76.7), median duration of response was not reached, and median (interquartile range) duration of treatment was 10.6 months (4.2–18.4). Conclusions Entrectinib resulted in rapid and durable responses in pediatric patients with solid tumors harboring NTRK1/2/3 or ROS1 fusions.

Severe neuropathy is a known adverse effect of vincristine in patients with Charcot-Marie-Tooth disease (CMT). We present the case of a 16-year-old girl with anaplastic medulloblastoma treated with gross total resection and high-dose craniospinal radiation with adjuvant vincristine chemotherapy who developed acute-onset severe quadriplegia and vocal cord paralysis. Vincristine and radiation therapy were discontinued. Although her neuropathy slowly improved over several weeks, she developed metastatic extraneural medulloblastoma and died 5 months after diagnosis. Subsequent genetic testing revealed previously asymptomatic and undiagnosed CMT1A. Our case highlights the importance of early recognition of acute vincristine neurotoxicity that should raise suspicion of an underlying hereditary neuropathy.