Marked inactivation of O6-alkylguanine-DNA alkyltransferase activity with protracted temozolomide schedules
2003

Temozolomide and AGAT Inactivation in Cancer Treatment

Sample size: 72 publication Evidence: moderate

Author Information

Author(s): Tolcher A W, Gerson S L, Denis L, Geyer C, Hammond L A, Patnaik A, Goetz A D, Schwartz G, Edwards T, Reyderman L, Statkevich P, Cutler D L, Rowinsky E K

Primary Institution: Institute for Drug Development, Cancer Therapy and Research Center, San Antonio, TX, USA

Hypothesis

Frequent temozolomide treatment may lead to significant inactivation of O6-alkylguanine-DNA alkyltransferase (AGAT), enhancing its anticancer effects.

Conclusion

The study found that protracted low-dose temozolomide schedules resulted in significant and sustained inactivation of AGAT in patients.

Supporting Evidence

  • Temozolomide showed a 47% response rate in patients with recurrent glioblastoma multiforme on a protracted schedule.
  • AGAT activity decreased by 72% after 7 days of daily temozolomide treatment.
  • Patients treated at maximum tolerated doses showed an 80.1% decrease in AGAT activity after 7 days.

Takeaway

This study shows that giving a cancer drug called temozolomide more often can make it work better by stopping a protein that helps cancer cells fix themselves.

Methodology

Patients with solid tumors received temozolomide on two different schedules, and AGAT activity was measured in their blood cells.

Limitations

The study was limited by the small number of patients who experienced severe thrombocytopenia, which may affect the generalizability of the findings.

Participant Demographics

Patients with solid malignancies refractory to standard therapy, aged 18 and older.

Statistical Information

P-Value

p<0.0001

Statistical Significance

p<0.0001

Digital Object Identifier (DOI)

10.1038/sj.bjc.6600827

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