Efficacy
Response rates vary from a low of 5% to a high of 50% with some CRs.
It is extremely difficult to measure response in patients with glioma. The appearance on an MRI scan can be a combination of recurrent tumour and radiation necrosis.
Neurological function must be taken into account. In addition to having a good MRI, the patient also needs to be functioning well.
Many newer glioma trials look more at time to progression or survival at 6, 12 and 24 months for drug efficacy.
The only randomised phase II trial involved 225 patients with recurrent glioblastoma. It demonstrated a statistically significant benefit of temozolomide over procarbazine with improvement in overall survival at 6 months (60% vs 44%, p = 0.019)) and progression free survival at 6 months (21% vs 8%, p = 0..008). Quality of life correlated with control of disease.r
Kaplan-Meier analysis of Fig 1) Progression-free survival and Fig 2) overall survival
© Br J Cancer 2000
Friedman et al reviewed the general experience with temozolomide in high grade glioma. Representative results from the non-randomized phase II studies are seen below.r
Friedman et al 2000 r |
Glioblastoma (single-arm) Arm 1 |
Anaplastic Astrocytoma ITT Arm 2 (n=162) |
6 month progression-free survival |
19% |
46% |
Median progression-free survival |
2.1 months |
5.4 months |
6 month overall survival |
46% |
75% |
Median overall survival |
5.4 months |
13.6 months |