Pilot study evaluating nicotinamide in metastatic brain tumors treated with radiation

Nicotinamide (NAM) has been shown to be an effective radiosensitizer in animal studies, but to date no clinical studies have substantiated this effect. Twenty-nine patients with brain metastases were randomized to receive NAM and external radiation therapy (RT) (n = 14) or irradiation alone (n = 15). NAM was started on day 1 at 3 g/day and continued until radiation was completed. The RT dose to the whole brain was 30 Gy in 10 fractions in 12–14 days. To evaluate response, a computed tomographic (CT) scan of the head was repeated 1 month post-treatment. Toxicity was graded from the skin, liver, and gastrointestinal tract. There were no toxicities observed at 39.0 g total dose of NAM. Median survival for the 29 patients, calculated by the Kaplan-Meier method, was 3.5 months for the NAM + RT group (14 patients) and 3.9 months for the RT alone group (15 patients). Eighteen patients were evaluable for 1 month tumor response by CT scan. Response rates were compared with Fisher's exact two-tailed test. There was no difference in complete response (CR) (P = 0.62) or CR + partial response (PR) (P = 1.000) between the two groups. Adjuvant NAM, given in doses of 3.0 g/day (39.0 g total dose) in the treatment of brain metastases, has shown no benefit in survival or response in this preliminary Study. © 1994 Wiley-Liss, Inc.