Glioblastoma is the most common type of primary brain tumor in adults. Around 90% of patients experience recurrence of the disease in its original location, and the median overall survival time when standard treatment fails with surgery, radiation, and chemotherapy is around 8 months.
"As a disease with a pattern of recurrence, resistance to chemotherapies and difficulty to treat, glioblastoma has needed durable treatments that can directly target the tumor while sparing healthy tissue," said study author, Andrew J. Brenner, MD, PhD, professor and chair of neuro-oncology research with Mays Cancer Center at The University of Texas Health Science Center at San Antonio, in a press release.
In the current study, researchers conducted a Phase 1 trial to investigate the maximum tolerated dose for drug formulation, Rhenium Obisbemeda (186RNL), for treating recurrent glioblastoma. Secondary objectives included safety and tolerability, dose distribution, overall survival rate, disease-specific progression-free survival, and overall survival.
The researchers recruited 21 patients who had failed one to three therapies, and administered the drug directly to their tumors using neuronavigation and convection catheters. Ultimately, the researchers observed significant increases in survival compared to historical controls.
Increases were especially prominent among patients with the highest absorbed doses- those exceeding 100 gray (Gy)- units of radiation. These patients had a median survival and progression-free time of 17 months and 6 months, respectively.
No dose-limiting toxic effects were observed, with most adverse effects considered to be unrelated to Rhenium Obisbemeda.
"The combination of a novel nanoliposome radiotherapeutic delivered by convection-enhanced delivery, facilitated by neuronavigational tools, catheter design and imaging solutions, can successfully and safely provide high absorbed radiation doses to tumors with minimal toxicity and potential survival benefit,” said Brenner.
"This trial provides hope, with a second phase under way and planned for completion by the end of this year,” he concluded.
Sources: Science Daily, Nature Communications