Drugs / O6-benzylguanine
last change Jun 2026 re-read 2 minutes ago

O6-benzylguanine

Small molecule targets AGT via inhibition

Developed for
central nervous system neoplasm · cancer of unknown primary site · gliosarcoma · mycosis fungoides and variants · primary cutaneous T-cell non-Hodgkin lymphoma · sarcoma · astrocytoma (excluding glioblastoma) · benign meningioma
+35 more · brain cancer · brain neoplasm · childhood brain stem glioma · childhood central nervous system germ cell tumor · childhood cerebellar astrocytic neoplasm · childhood cerebral astrocytoma · childhood choroid plexus neoplasm · childhood germ cell tumor · childhood malignant neoplasm · childhood medulloblastoma · childhood oligodendroglioma · colorectal cancer · craniopharyngioma · cutaneous melanoma · ependymoblastoma · extragonadal germ cell tumor · grade II meningioma · grade III meningioma · kidney cancer · liver cancer · lymphoma · medulloepithelioma · mixed glioma · neuroblastoma · oligoastrocytoma · oligodendroglioma · optic pathway glioma · ovarian cancer · pediatric infratentorial ependymoma · pediatric supratentorial ependymoma · pineoblastoma · plasma cell myeloma · subependymal giant cell astrocytoma · supratentorial primitive neuroectodermal tumor · glioblastoma
Investigated by
National Cancer Institute (NCI) · Duke University · Case Comprehensive Cancer Center · Keryx / AOI Pharmaceuticals, Inc. · Fred Hutchinson Cancer Center · University of Chicago
+7 more · Children's Hospital Medical Center, Cincinnati · Leland Metheny · Pediatric Brain Tumor Consortium · Pharmacia · SWOG Cancer Research Network · Schering-Plough · Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins

Trials 30 · a red edge is where a trial was stopped

PhaseRegistry idDatesIndicationSponsorStatusOutcome
Phase 114 trials
Phase 1 NCT00612989 Feb 2005 → Aug 2007 gliosarcoma Duke University Completed No outcome recorded
Phase 1 NCT00612638 Jan 2005 → Jan 2007 gliosarcoma Duke University Completed No outcome recorded
Phase 1 NCT00086970 Jun 2004 → Nov 2005 cancer of unknown primary site National Cancer Institute (NCI) Terminated No outcome recorded
Phase 1 NCT00045721 Mar 2003 → Jul 2004 central nervous system neoplasm Pediatric Brain Tumor Consortium Terminated No outcome recorded
Phase 1 NCT00052780 Oct 2002 → Nov 2007 benign meningioma, childhood brain stem glioma, childhood central nervous system germ cell tumor, childhood cerebellar astrocytic neoplasm +16 National Cancer Institute (NCI) Completed No outcome recorded
Phase 1 NCT00006474 Mar 2001 → Aug 2004 central nervous system neoplasm Duke University Completed No outcome recorded
Phase 1 NCT00020150 Jun 2000 → ? central nervous system neoplasm, childhood germ cell tumor, childhood malignant neoplasm, extragonadal germ cell tumor +5 National Cancer Institute (NCI) Completed No outcome recorded
Phase 1 NCT00004892 Apr 2000 → ? central nervous system neoplasm National Cancer Institute (NCI) Completed No outcome recorded
Phase 1 NCT00003766 Oct 1999 → Nov 2001 cancer of unknown primary site University of Chicago Completed No outcome recorded
Phase 1 NCT00003765 May 1999 → Mar 2006 central nervous system neoplasm National Cancer Institute (NCI) Completed No outcome recorded
Phase 1/22 trials
Phase 1/2 NCT00961220 Feb 2010 → Apr 2012 mycosis fungoides and variants, primary cutaneous T-cell non-Hodgkin lymphoma National Cancer Institute (NCI) Completed No outcome recorded
Phase 1/2 NCT00669669 Feb 2009 → Jul 2018 gliosarcoma Fred Hutchinson Cancer Center Terminated No outcome recorded
Phase 211 trials
Phase 2 NCT05052957 Jan 2023 → Jun 2026 overdue adult glioblastoma, gliosarcoma Leland Metheny Recruiting No outcome recorded
Phase 2 NCT00436436 Nov 2006 → Mar 2010 central nervous system neoplasm National Cancer Institute (NCI) Terminated No outcome recorded
Phase 2 NCT00389090 Oct 2006 → Jun 2008 astrocytoma (excluding glioblastoma), oligoastrocytoma, oligodendroglioma Keryx / AOI Pharmaceuticals, Inc. Terminated No outcome recorded
Phase 2 NCT00275002 Feb 2006 → Dec 2010 central nervous system neoplasm National Cancer Institute (NCI) Completed No outcome recorded
Phase 2 NCT00362921 Apr 2004 → Aug 2007 brain neoplasm Duke University Completed No outcome recorded
Phase 2 NCT00005081 Aug 2000 → Apr 2001 central nervous system neoplasm Duke University Completed No outcome recorded
Phase 2 NCT00005981 Jun 2000 → Nov 2003 colorectal cancer Case Comprehensive Cancer Center Completed No outcome recorded
Phase 2 NCT00005066 Jun 2000 → Sep 2001 sarcoma University of Chicago Completed No outcome recorded
Phase 2 NCT00005961 Jun 2000 → Dec 2005 cutaneous melanoma National Cancer Institute (NCI) Completed No outcome recorded
Phase 2 NCT00004072 Sep 1999 → Aug 2004 plasma cell myeloma Case Comprehensive Cancer Center Completed No outcome recorded
Phase 31 trial
Phase 3 NCT00017147 Sep 2001 → May 2006 brain cancer SWOG Cancer Research Network Completed No outcome recorded
Phase not applicable2 trials
NCT01769911 Feb 2015 → Feb 2019 Burkitt lymphoma, Hodgkins lymphoma, MALT lymphoma, T-cell large granular lymphocyte leukemia +20 Fred Hutchinson Cancer Center Withdrawn No outcome recorded
NCT00253487 Aug 2005 → Aug 2012 central nervous system neoplasm Children's Hospital Medical Center, Cincinnati Completed No outcome recorded
Also used as a comparator or background therapy in 4 trials
PhaseRegistry idDatesIndicationSponsorStatusOutcome
Phase 13 trials
Phase 1 NCT02343666 Background Aug 2016 → Aug 2020 HIV infectious disease, Hodgkins lymphoma, non-Hodgkin lymphoma Fred Hutchinson Cancer Center Withdrawn No outcome recorded
Phase 1 NCT01269424 Comparator Nov 2011 → Dec 2020 glioblastoma Stanton Gerson MD Completed No outcome recorded
Phase 1 NCT00003348 Background May 1998 → Aug 2000 central nervous system neoplasm Duke University Completed No outcome recorded
Phase 21 trial
Phase 2 NCT00613093 Comparator Oct 2002 → Mar 2006 glioblastoma Duke University Completed No outcome recorded

Evidence & citations 10 cited values

Every value below carries the sentence it was read from. 41 sources stand behind the page.

FieldValueCited text
Known as O(6)-benzylguanine O(6)-benzylguanine (O(6)-BG), an inhibitor of host alkylation repair, and BCNU were studied in children with refractory/untreatable central nervous system tumors to determine...” PMID 17941066 Mar 2008
38

“At registration, patients were randomized to Arm 1, which consisted of therapy with O(6)-benzylguanine (O(6)-BG) + BCNU 40 mg/m(2) (reduced dose) + radiation therapy (RT) (O6BG...” PMID 25407559 Nov 2014

“Temozolomide pharmacokinetics were evaluated in children receiving concurrent O(6)-benzylguanine (O(6)BG), which enhanced the hematological toxicity of temozolomide.” PMID 19430790 May 2009

O(6)-Benzylguanine and Temozolomide in Treating Patients With Glioblastoma Multiforme That Did Not Respond to Previous Temozolomide and Radiation Therapy” NCT00436436

“PURPOSE: Phase I trial to study the effectiveness of O(6)-benzylguanine given before surgery to patients who have malignant glioma.” NCT00002971

“O6-benzylguanine (O6-BG)” NCT00612638

NCT00253487

NCT05052957

NCT00002604

NCT00003766

NCT01269424

NCT00003348

NCT00003765

NCT00006474

NCT00046878

NCT00362921

NCT00004892

NCT00005081

NCT00961220

NCT00005961

NCT00669669

NCT00003613

NCT02343666

NCT00003567

NCT00002971

NCT00017147

NCT00275002

NCT00613093

NCT00612989

NCT01769911

NCT00052780

NCT00389090

NCT00436436

NCT00045721

NCT00004072

NCT00086970

NCT00005981

NCT00005066

NCT00020150

Known as NSC 637037 “Mutant MGMT Gene Transfer Into Human Hematopoietic Progenitors to Protect Hematopoiesis During O6-Benzylguanine (BG, NSC 637037) and Carmustine Followed by Temozolomide Therapy...” NCT00003567
1

“A Phase II Trial of O6-Benzylguanine (NSC 637037) and BCNU (Carmustine) in Patients With Metatstatic Melanoma” NCT00005961

Known as O-Benzylguanine “A Phase 2 Study of O-Benzylguanine (O-BG) and Temozolomide in Patients With Glioblastoma Progressing at Least 3 Months After Completion of Primary Treatment With Radiation...” NCT00436436
Known as O-BG “A Phase 2 Study of O-Benzylguanine (O-BG) and Temozolomide in Patients With Glioblastoma Progressing at Least 3 Months After Completion of Primary Treatment With Radiation...” NCT00436436
Known as O6-Benzylguanine - O6-BG O6-Benzylguanine - O6-BGNCT00613093
1

“O6-Benzylguanine-O6-BG” NCT00612638

Known as O6-BG “PURPOSE: This phase II trial was designed to define the efficacy of Gliadel wafers in combination with an infusion of O6-benzylguanine (O6-BG) that suppresses tumor...” PMID 19188181 Feb 2009
11

“PURPOSE: This pediatric phase I trial of O6-benzylguanine (O6BG) and temozolomide (TMZ) on a daily schedule for 5 days, every 28 days was performed to determine the...” PMID 16234526 Oct 2005

“This phase I clinical trial conducted with patients who had recurrent or progressive malignant glioma (MG) was designed to determine the maximum tolerated dose (MTD) and...” PMID 19289491 Mar 2009

“O(6)-benzylguanine (O(6)-BG), an inhibitor of host alkylation repair, and BCNU were studied in children with refractory/untreatable central nervous system tumors to determine...” PMID 17941066 Mar 2008

“Determine the dose of O6-benzylguanine (O6-BG) that produces total depletion of tumor O6-alkylguanine-DNA alkyltransferase (AGT) levels in more than 90% of patients with...” NCT00002971

“To determine the cutaneous T-cell Lymphoma (CTCL) response rate and safety of O6BG (O6-benzylguanine) /BCNU (carmustine) when given biweekly as two consecutive daily doses.” NCT00961220

“Temozolomide pharmacokinetics were evaluated in children receiving concurrent O(6)-benzylguanine (O(6)BG), which enhanced the hematological toxicity of temozolomide.” PMID 19430790 May 2009

“This phase I trial was designed to (1) establish the dose of O6-benzylguanine (O6-BG) administered intravenously as a continuous infusion” PMID 17264335 Feb 2007

“Patients receive O6-benzylguanine (O6-BG) IV over 1 hour followed 30 minutes later by oral temozolomide daily for 5 days.” NCT00020150

“Patients receive O(6)-benzylguanine (O6-BG) IV over 1 hour immediately followed by O6-BG IV continuously for 9 days.” NCT00045721

“Patients receive a single dose of O6-benzylguanine (O6-BG) IV over 1 hour at one of two dose levels.” NCT00003766

NCT00612638

Action Inhibit “baseline O6-alkylguanine DNA alkyltransferase (AGT) activity in circulating peripheral blood mononuclear cells decreases by greater than 90% at 2 hours after BG infusion.” NCT00002604
Modality Small molecule “low molecular-weight purine analog” NCT05052957
Route Intravenous “Patients receive BG IV over 1 hour during week 1” NCT00002604
Target AGT “Correlate tumor tissue AGT depletion with AGT depletion in peripheral blood mononuclear cells (PBMC) obtained at a specified time after O6-BG administration” NCT00003766