Clinical Trials

Multiple Phase 1 through Phase 3 clinical trials, with statuses ranging from completed and active to recruiting and terminated, explore this intervention for high-risk neuroblastoma, endometrial cancer, melanoma, uterine neoplasms, and prostate cancer. Led by academic institutions and cooperative groups—including the New Approaches to Neuroblastoma Therapy Consortium, M.D. Anderson Cancer Center, and the Radiation Therapy Oncology Group—these studies evaluate diverse treatment strategies. In particular, early-phase protocols assess buthionine sulfoximine combined with chemotherapy like melphalan to overcome drug resistance in neuroblastoma.

NCT Number Recruitment Conditions Sponsor/Collaborators Start Date Phases
NCT04073706 RECRUITING
Endometrial Cancer Stage I; Sentinel Lymph Node; Surgery
Queensland Centre for Gynaecological Cancer
 2021-01-18 PHASE3
NCT01820884 ACTIVE_NOT_RECRUITING
Endometrial Neoplasms
Ding Ma
 2012-11
NCT03744494 COMPLETED
Prostate Cancer; Quality of Life; Orchiectomy
University College Hospital, Ibadan
 2016-03-02
NCT00005835 COMPLETED
Neuroblastoma
New Approaches to Neuroblastoma Therapy Consortium
 2001-08 PHASE1
NCT01619800 TERMINATED
Chronotropic Incompetence
Vivek Reddy
 2012-03
NCT01369654 COMPLETED
Surgical Procedure, Unspecified
University of California, San Francisco
 2011-05
NCT00002706 COMPLETED
Endometrial Adenocarcinoma; Stage I Uterine Corpus Cancer; Stage I Uterine Sarcoma; Stage II Uterine Corpus Cancer; Stage II Uterine Sarcoma
Gynecologic Oncology Group
 1996-04 PHASE3
NCT00661336 WITHDRAWN
Melanoma (Skin)
Duke University
 2008-04 PHASE1
NCT00002807 COMPLETED
Endometrial Cancer
NCIC Clinical Trials Group
 1996-07-04
NCT00505492 TERMINATED
Uterine Neoplasms
M.D. Anderson Cancer Center
 2002-02 PHASE2
NCT00006027 COMPLETED
Endometrial Cancer
Radiation Therapy Oncology Group
 2000-08 PHASE3
NCT00002730 COMPLETED
Neuroblastoma
New Approaches to Neuroblastoma Therapy Consortium
 1996-06 PHASE1

(data from https://clinicaltrials.gov, updated on 2026-01-30)

Check the L-Buthionine-(S,R)-sulfoximine (L-BSO) product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

Compliance for Clinical Use

Mechanism and Biochemical Profile

L-Buthionine-(S,R)-sulfoximine acts as a potent, cell-permeable, and irreversible inhibitor of γ-glutamylcysteine synthetase, thereby blocking the rate-limiting step of glutathione biosynthesis and markedly depleting intracellular glutathione levels. This disruption of cellular antioxidant defenses impairs redox homeostasis and sensitizes tumor cells to chemotherapy-induced oxidative damage, demonstrating therapeutic relevance in malignancies such as neuroblastoma and melanoma.

Appendix RUO and cGMP Quality Standards

Quality Dimension RUO (Research Use Only) cGMP (Current Good Manufacturing Practice)
Clinical Applicability Prohibited in human clinical trials or medical diagnostics. Mandatory for human clinical trials (Phase I–III) and therapies.
Regulatory Status Non-regulated grade; exempt from drug manufacturing laws. Legally enforced by health authorities (e.g., FDA, EMA, NMPA).
Facility Environment Unclassified analytical or research laboratories. Validated Cleanrooms (ISO Class 5–8) with continuous monitoring.
Quality Control Basic purity and activity testing. Rigorous safety release testing (Sterility, Endotoxin, Mycoplasma).
Process Validation Basic equipment calibration; no process validation required. Full qualification (IQ/OQ/PQ) and complete batch records.
Quality Assurance Vendor self-declared without required formal QMS. Mandatory QA/QC unit, Change Control, CAPA, and vendor audits.
Regulatory Impact High risk of IND rejection if used as a critical raw material. Required for IND/NDA filings, supported by Drug Master Files (DMF).

Footnotes

Regulatory Note: Governed by FDA (21 CFR Parts 210/211/312), EMA (EudraLex Vol 4), ICH Guidelines (E6/Q7/Q9/Q10), and compendial standards (USP <71>/<85>/<1043>).

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Note: Technical data last updated: Sep 1, 2026.