In case of recurrent GBM tas in the case of your husband the best option is the drug Avastin
administered at a dose of 10mg/kg intravenous every 2 weeks.
The main side effect of avastin is hypertension
for which dose reductions may be required.
When Avastin is given in combination with another drug irinotecan the dose of avastin remains the same and irinotecan is dosed at 340 mg/m2 for patients on enzyme inducing anticonvulsants and 125 mg/m2 for patients not on enzyme inducing anticonvulsants.
Both the drugs are dissolved in IV fluid and administered over 1 hr over vein.