Dacarbazine (DTIC) in malignant melanoma: reduced toxicity with protection from light.

Dacarbazine (dimethyl triazeno imidazole carboxamide, DTIC, NSC-45388), is the most effective oncolytic agent in the treatment of advanced malignant melanoma, but its side effects are considerable. These side effects are thought to be due to its photodegradation, which occurs within a few minutes of exposure to light. Fifteen patients with metastatic malignant melanoma were treated with dacarbazine protected from light, without troublesome haematological or other side effects. There was complete disappearance of metastases in 27% of cases and partial response in 47%. All lesions in skin, lungs and liver responded, but only half of the lymph node metastases showed response. It is suggested that dacarbazine should be protected from light during preparation and administration so as to reduce toxicity without influencing response.