Interim Results of a Phase II Study of Hypofractionated Radiotherapy with Concurrent Temozolomide Followed by Adjuvant Temozolomide in Patients over 70 Years Old with Newly Diagnosed Glioblastoma.

Objective: In this phase II study, we investigate clinical outcomes and tolerability of hypofractionated radiotherapy (HRT) combined with temozolomide (TMZ) to treat elderly patients with glioblastoma (GBM).

Methods: Patients 70 years of age or older with newly diagnosed GBM received HRT to a dose of 34 Gy given in ten fractions over 2 weeks, delivered with concurrent and adjuvant TMZ.

Results: In this interim analysis, ten patients were enrolled on trial from 12/1/2015 to 4/5/2017. With a median follow-up of 9 months (range 3-12 months), median progression-free survival (PFS) was 6 months. The median overall survival (OS) has not been reached. Estimated 1-year OS and PFS rates were 53.3 and 44.4%, respectively. All patients completed the full course of RT, with no patients developing grade 3 or higher adverse events from treatment.

Conclusions: The preliminary results of our phase II trial suggest HRT delivered over 2 weeks with concurrent and adjuvant TMZ is well tolerated in elderly patients with GBM without compromising clinical outcomes.