Human embryonic stem cell-derived oligodendrocyte progenitors remyelinate the brain and rescue behavioral deficits following radiation.

Radiation therapy to the brain is a powerful tool in the management of many cancers, but it is associated with significant and irreversible long-term side effects, including cognitive decline and impairment of motor coordination. Depletion of oligodendrocyte progenitors and demyelination are major pathological features that are particularly pronounced in younger individuals and severely limit therapeutic options. Here we tested whether human ESC-derived oligodendrocytes can functionally remyelinate the irradiated brain using a rat model. We demonstrate the efficient derivation and prospective isolation of human oligodendrocyte progenitors, which, upon transplantation, migrate throughout the major white matter tracts resulting in both structural and functional repair. Behavioral testing showed complete recovery of cognitive function while additional recovery from motor deficits required concomitant transplantation into the cerebellum. The ability to repair radiation-induced damage to the brain could dramatically improve the outlook for cancer survivors and enable more effective use of radiation therapies, especially in children.

Phase 2 trial of concurrent 5-fluorouracil, hydroxyurea, cetuximab, and hyperfractionated intensity-modulated radiation therapy for locally advanced head and neck cancer.

BACKGROUND: The objective of this phase 2 study was to evaluate the tolerability and efficacy of incorporating cetuximab and simultaneous integrated-boost (SIB), intensity-modulated radiation therapy (IMRT) into a well described 5-fluorouracil (5-FU) and hydroxyurea (HU)-based chemoradiation regimen. METHOD: Patients with stage IVA and IVB or high-risk stage III squamous cell carcinomas of the head and neck were enrolled on a phase 2 trial. Prior organ-conserving surgery or induction chemotherapy was allowed off protocol. SIB-IMRT was prescribed to low-risk volumes (43.2 gray [Gy] to 48 Gy) and intermediate-risk volumes (54-63 Gy). A separate IMRT cone-down plan was targeted to macroscopic disease (72 Gy). The median radiation dose was 72 Gy (range, 60-72 Gy) administered in 1.5 Gy fractions twice daily during Weeks 1, 3, 5, 7 and 9. Concurrent systemic therapy consisted of 5-FU (600 mg/m²), HU (500 mg twice daily), and cetuximab (250 mg/m²). RESULTS: From January 2007 through April 2008, 33 patients were enrolled. At a median follow-up of 24 months, the 2-year rates of locoregional control, distant control, disease-free survival, and overall survival were 83%, 79%, 69%, and 86%, respectively. Grade 3 toxicity consisted of mucositis in 33% of patients, radiation dermatitis in 15%of patients, anemia in 18% of patients, leukopenia in 18% of patients, neutropenia in 12% of patients, and thrombocytopenia in 3% of patients. Most patients (64%) were able to tolerate treatment without a feeding tube, and there were no acute or late grade ≥4 adverse events. CONCLUSIONS: The current results indicated that concurrent 5-FU, HU, and cetuximab plus SIB-IMRT is a promising and reasonably well tolerated approach to incorporating molecularly targeted therapy into curative therapy for patients with locally advanced head and neck cancer.