Phase II Weekly Vinblastine for Chemotherapy-Naïve Children With Progressive Low-Grade Glioma: A Canadian Pediatric Brain Tumor Consortium Study

Abstract

Purpose Vinblastine monotherapy has shown promising activity and a low-toxicity profile in patients with pediatric low-grade glioma (PLGG) who experienced treatment failure after initial treatment with chemotherapy and/or radiation. The aim of this study was to assess the activity of vinblastine in therapy-naïve children. Patients and Methods Patients < 18 years old with unresectable and/or progressive therapy-naïve PLGG were eligible. Vinblastine was administered once per week at a dose of 6 mg/m intravenously over a period of 70 weeks. Vision, quality of life, neurofibromatosis type 1 (NF1) status, and BRAF mutation/fusion status were also determined and correlated with outcome. Results Fifty-four patients were enrolled onto the study, with a median age of 8 years (range, 0.7 to 17.2 years). Most patients had chiasmatic/hypothalamic tumors (55.5%), and 13 patients (24.1%) had NF1. The most common histology was pilocytic astrocytoma (46.3%). Seventeen patients were diagnosed using radiologic criteria alone. Best response to chemotherapy was centrally reviewed with a response rate (complete, partial, or minor response) of 25.9%. Disease stabilization (complete, partial, or minor response or stable disease) was achieved in 47 patients (87.0%). Visual improvement was observed in 20% of patients with optic pathway glioma. Five-year overall survival and progression-free survival (PFS) rates were 94.4% (95% CI, 88.5% to 100%) and 53.2% (95% CI, 41.3% to 68.5%), respectively, for the entire cohort. Patients with NF1 had a significantly better PFS (85.1%; 95% CI, 68.0% to 100%) when compared with patients without NF1 (42.0%; 95% CI, 29.1% to 60.7%; P = .012). Age< 3 years or > 10 years was not associated with poor outcome. Treatment was well tolerated, and quality of life was not affected during treatment. In this trial, there was no correlation between BRAF alterations and outcome. Conclusion Vinblastine administered once per week is well tolerated in children with treatment naïve PLGG. Overall survival and PFS are comparable to current therapies, with a favorable toxicity profile and a maintained quality of life.

Adolescents and young adults with brain tumors in the context of molecular advances in neuro‐oncology

“…When treatment is required, chemotherapy with low risk of late effects is the preferred option . For example, vincristine/carboplatin, monthly carboplatin, TPCV (thioguanine, procarbazine, CCNU, vincristine), or weekly vinblastine monotherapy were shown to achieve 5‐year event‐free survival ranging between 40 and 50% . However, the tolerability should be considered in the AYA population due to the higher risk of vincristine neurotoxicity and gonadal toxicity of procarbazine in males .…”

Carboplatin and vincristine neurotoxicity in the treatment of pediatric low‐grade gliomas

“…Neurotoxic side effects associated with CV should be carefully considered when selecting a chemotherapy regimen for LGG. Other regimens, such as weekly vinblastine, appear to offer similar tumor control without significant neurotoxicity . If CV is initiated, neurological status should be carefully assessed at each visit by an oncologist with a detailed neurologic exam, including deep tendon reflexes, sensation, and strength.…”

Effective and safe tumor inhibition using vinblastine in medulloblastoma

“…Recent protocols such as SJMB12 (NCT01878617) and PNET5 (NCT02066220) modestly reduce the vincristine dose; however, it is unclear whether this will compromise survival, and a substantial proportion of patients will still suffer from toxicity. Vinblastine monotherapy in patients with low‐grade glioma resulted in event‐free survival comparable to or exceeding that with carboplatin/vincristine, with minimal peripheral neuropathy suggesting that this could be an effective substitution . We present two cases of medulloblastoma in adolescents where vincristine was poorly tolerated, and successfully replaced with vinblastine.…”