Temozolomide Stops Growth of Gliomas in Long-term Study

October 21, 2003

Martha Kerr

Oct. 21, 2003 (San Francisco) — The alkylating agent temozolomide (Temadar; Schering-Plough) is showing long-term safety and efficacy in the treatment of malignant gliomas in a study that is underway in Chicago. Results were presented here during the 128th annual meeting of the American Neurological Association, where researchers are saying that long-term treatment of gliomas is now a reality.

The study involved 16 patients with gliomas, 14 with grade 3 or 4 malignancies and two patients with low-grade gliomas. Age range was 26 to 59 years at baseline, and all patients had received at least 26 months of temozolomide at enrollment, with treatment duration ranging from 18 to 44 months.

Tumor types in the study population included glioblastomas, anaplastic astrocytomas, anaplastic oligodendrogliomas, anaplastic mixed gliomas and low-grade oligodendrogliomas.

Jennifer I. Stern, MD, from the Department of Neurology at Northwestern University, Feinberg School of Medicine, in Chicago, Illinois, reported that 10 patients remain in the study. "In all 10, tumor size is stable or smaller," Dr. Stern told Medscape.

Tumors progressed in two patients and the drug was discontinued, Dr. Stern reported. In another four patients, the drug was discontinued for other reasons: two patients elected to discontinue treatment, a rash developed in a third patient, and temozolomide therapy was stopped in a fourth patient for other reasons, "but in all four of these patients, tumor size was stable or smaller at the time temozolomide was stopped," Dr. Stern said.

Adverse effects of temozolomide were generally mild, Dr. Stern said. The most commonly reported adverse effects were fatigue, nausea, and vomiting. Four patients experienced thrombocytopenia, and neutropenia occurred in three patients. Treatment was temporarily discontinued in these seven patients. One patient required a blood transfusion, but senior investigator Nicholas A. Vick, MD, stressed that "none of these side effects were life-threatening. That is what is so exciting about this drug."

Temozolomide was approved in 1999 for the treatment of a number of brain tumors. But Dr. Stern noted that the approved duration of treatment was for a maximum of two years. "There has been little or no data on the efficacy or toxicity of temozolomide treatment beyond two years," she commented.

Of the three patients in the study with malignant glioblastomas, tumor size is stable or smaller after as long as 30 months after the initiation of temozolomide therapy. "The life expectancy in malignant glioblastoma is six to 12 months, so this is impressive," Dr. Stern noted. She added that for all patients in the study, "the vast majority are functional and leading normal lives."

Prior to the approval of temozolomide, long-term treatment of glioblastomas wasn't possible because of the high toxicity of the drugs available, Dr. Vick noted. "Patients' blood counts would go to hell.

"We have never been able to talk about maintenance treatment for glioblastomas before," Dr. Vick told Medscape. "It's been like talking about pigs flying."

ANA 128th Annual Meeting: Neuro-oncology posters. Presented Oct. 20, 2003.

Reviewed by Gary D. Vogin, MD

Martha Kerr is a freelance writer for Medscape.

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