Iniparib for Newly Diagnosed Glioblastoma (GBM) Brain Tumors

The brain tumor glioblastoma ( GBM ) is one of the most intensively researched cancers. Many new drugs are being tested in brain tumors. One is iniparib , a prodrug claimed to cause cell death through intracellular conversion of radical nitrogen ions. A phase-2 clinical trialevaluated the effectiveness and safety of adding iniparib to standard radiation therapy (RT) and temozolomide (TMZ) in newly diagnosed glioblastoma (GBM) patients.

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Study Details

The study's primary objective was to measure median overall survival. Comparisons were made with survival rates of GBM patients with the same characteristics who had received standard treatment (historical control arm).

In the phase-1 (safety) study, 5 patients, and in the phase-2 (efficacy) study, 76 GBM patients received radiotherapy and oral temozolomide chemotherapy together with intravenous iniparib at a dose of approximately 8 mg/kg.

The median age of the 81 evaluable participants was 58. Median survival in these 81 patients was 22 months, and adding iniparib to standard treatment reduced the risk of death by % 56. The 2- and 3-year survival rates were % 38 and % 25, respectively.

Treatment-related severe (grade 3) adverse effects occurred in % 27 of patients; nine patients experienced adverse effects requiring discontinuation. Iniparib-related infusion adverse effects included rash, gastritis (stomach complaints), elevated liver enzymes and thrombocytopenia (decreased platelets).

Conclusion

Iniparib was well tolerated in newly diagnosed GBM patients at doses up to 17.2 mg/kg weekly alongside radiotherapy and temozolomide. It was observed to prolong median overall survival compared with the historical control group. Although dose optimization is needed before further studies, these iniparib results are very promising for GBM patients, whose treatment options are very limited.