Metformin, Neo-adjuvant Temozolomide and Hypo- Accelerated Radiation Therapy Followed by Adjuvant TMZ in Patients With GBM

Official Title

Metformin and Neo-adjuvant Temozolomide and Hypofractionated Accelerated Limited-margin Radiation Therapy Followed by Adjuvant Temozolomide in Patients With Glioblastoma Multiforme (M-HARTT STUDY)


Glioblastoma Multiforme is one of the most common, and unfortunately one of the most aggressive brain tumours in adults with most of the patients recurring and dying of the disease with a median survival of 16 months from diagnosis. Current treatment for patients with newly diagnosed Glioblastoma Multiforme (GBM) is safe maximal surgical resection followed by concomitant conventional Radiation Therapy (RT) delivered in 6 weeks + Temozolomide (TMZ) followed by TMZ for 6 to 12 cycles. Recent scientific research has shown that Metformin, a common drug used to treat diabetes mellitus, may improve the results of the treatment in patients with a variety of cancers, such as breast, colon, and prostate cancer. Metformin is an attractive and safe medication to be used in this group of patients because of its very low toxicity. In our centre the investigators have been using TMZ for 2 weeks prior to a short course (4 weeks) of RT which equivalent to the standard RT of 6 weeks. Temozolomide is used 2 weeks before RT + TMZ, and this is followed by the 6 to 12 cycles of TMZ. Our results are quiet encouraging with a median survival of 20 months, and acceptable toxicity.

Trial Description

Primary Outcome:

  • Number of patients completing the study treatment
Secondary Outcome:
  • To assess toxicity of the regimen
Metformin, a drug with a very safe toxicity profile, is an attractive molecule to be tested in patients with newly diagnosed GBM in a phase I clinical trial. This is based on its potential to inhibit the proliferation of GBM CSCs through its mechanism of action which is similar to IR and TMZ. Metformin, IR, and TMZ stimulate AMPK leading to the subsequent inhibition of cellular proliferation. Therefore, it is hypothesized that the addition of Metformin to concomitant IR and TMZ may increase the efficiency of IR and TMZ, which are currently considered as the standard of care for patients with GBM. In addition, Metformin lowers blood glucose levels, and subsequently reduces the insulin and Insulin-Growth-factors which are growth-promoting factors with a direct impact on GBM cellular proliferation and invasion. Metformin may improve the outcomes of patients with GBM when added to current treatment consisting of maximal safe surgical resection followed by neo-adjuvant TMZ and concomitant accelerated hypofractionated limited-margin XRT followed by adjuvant TMZ. Our Neuro-Oncology group at McGill University reviewed the results of an ongoing Phase II study in patients with GBM. A group of 33 patients were treated according to protocol, and with a median follow-up of 11 months, the median survival was 17.5 months which compares favourably to current results from standard treatment with a beneficial 2-week shortening of the XRT treatment time. This is a phase II clinical trial to assess the feasibility and overall toxicity of adding Metformin to Neoadjuvant Temozolomide followed by concomitant Temozolomide and accelerated hypofractionated limited-margin radiation therapy and followed by adjuvant Temozolomide in patients with newly diagnosed GBM. It is expected that the proposed study treatment will improve the median survival from current values of 20 months (current MUHC Neo-adjuvant Phase 2 data) to 25 months. This means an improved outcome of 25%. Using one-tailed statistics, and with a power of 0.8 and an alpha of 0.05, the sample size for this Phase II trial will be 50 patients.

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