Inhibition of DNA repair with MGMT pseudosubstrates: phase I study of lomeguatrib in combination with dacarbazine in patients with advanced melanoma and other solid tumours
- PMID: 21811257
- PMCID: PMC3171007
- DOI: 10.1038/bjc.2011.285
Inhibition of DNA repair with MGMT pseudosubstrates: phase I study of lomeguatrib in combination with dacarbazine in patients with advanced melanoma and other solid tumours
Abstract
Background: The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) reverses the O6-methylguanine (O6-meG) lesion induced by dacarbazine. Depletion of MGMT can be achieved using O6-meG pseudosubstrates. Herein, we report the first phase I experience of the novel O6-meG pseudosubstrate lomeguatrib, combined with dacarbazine.
Methods: This is a phase I dose-escalation study to determine the maximum tolerated dose and recommended phase II dose (RP2D) of lomeguatrib combined with a single dose of dacarbazine on a 21-day schedule.
Results: The vast majority of the 41 patients enrolled had metastatic melanoma (36/41) and most had no previous chemotherapy (30/41). The most frequent non-hematological adverse events (AEs) were nausea (52%), and fatigue (42%). The most frequent AEs of grade 3-4 severity were neutropaenia (42%), leukopaenia (17%), and thrombocytopaenia (12%). Only 1 patient had a partial response and 10 patients had stable disease.
Conclusion: The RP2D of lomeguatrib was 40 mg orally twice daily for 10 days combined with 400 mg m(-2) of dacarbazine IV on day 2. Oral administration of lomeguatrib substantially increases the haematological toxicity of dacarbazine consistent with experience with other O6-meG pseudosubstrates.
References
-
- Ayi TC, Loh KC, Ali RB, Li BF (1992) Intracellular localization of human DNA repair enzyme methylguanine-DNA methyltransferase by antibodies and its importance. Cancer Res 52(23): 6423–6430 - PubMed
-
- Barth A, Wanek LA, Morton DL (1995) Prognostic factors in 1521 melanoma patients with distant metastases. J Am Coll Surg 181(3): 193–201 - PubMed
-
- Batts ED, Maisel C, Kane D, Liu L, Fu P, O'Brien T, Remick S, Bahlis N, Gerson SL (2007) O6-benzylguanine and BCNU in multiple myeloma: a phase II trial. Cancer Chemother Pharmacol 60(3): 415–421 - PubMed
-
- Brock CS, Newlands ES, Wedge SR, Bower M, Evans H, Colquhoun I, Roddie M, Glaser M, Brampton MH, Rustin GJ (1998) Phase I trial of temozolomide using an extended continuous oral schedule. Cancer Res 58(19): 4363–4367 - PubMed
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Medical
Research Materials
