Arsenic Trioxide

證據等級: L5

預測適應症: 10 個

ARSENIC TRIOXIDE: From Acute Promyelocytic Leukemia to Myelodysplastic Syndrome

One-Sentence Summary

Arsenic Trioxide (ATO) is an established antineoplastic agent for Acute Promyelocytic Leukemia (APL), acting through apoptosis induction, abnormal leukemic cell differentiation, and NF-κB pathway inhibition. The TxGNN model predicts it may be effective for Myelodysplastic Syndrome (MDS) — the highest-evidence indication among 10 candidate predictions, with MDS-related diseases occupying the top 6 ranks. This direction is currently supported by 24 registered clinical trials and 20 publications, including a 2023 meta-analysis and a 2025 randomized clinical study.

Quick Overview

Item	Content
Original Indication	Acute Promyelocytic Leukemia (APL)
Predicted New Indication	Myelodysplastic Syndrome (MDS)
TxGNN Prediction Score	99.91%
Evidence Level	L2
Malaysia Market Status	✓ Marketed
Number of Registrations	1
Recommended Decision	Proceed with Guardrails

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available in this Evidence Pack. Based on known pharmacology, Arsenic Trioxide is a multi-target antineoplastic compound. In APL, its primary mechanism involves degradation of the PML-RARα oncofusion protein and induction of leukemic blast differentiation. Beyond APL, ATO generates reactive oxygen species (ROS) that selectively kill malignant cells, inhibits the pro-survival NF-κB transcription factor, and suppresses Bcl-2/FLIP anti-apoptotic proteins — mechanisms that are broadly applicable to haematological malignancies.

Both APL and MDS are clonal disorders of myeloid progenitor cells. In MDS, dysplastic haematopoietic stem cell clones accumulate in the bone marrow, driving ineffective blood cell production through mechanisms that include elevated NF-κB activity and dysregulated apoptosis. Mechanistic studies have confirmed that NF-κB activity is significantly upregulated in higher-risk MDS subtypes (RAEB), and that ATO can modulate BCL2 family gene expression in patients’ bone marrow samples in vivo (PMID 16105982, PMID 22964015). This provides a direct molecular rationale connecting ATO’s known mechanism to MDS pathobiology.

A particularly compelling repurposing argument lies in the demonstrated synergy between ATO and hypomethylating agents (decitabine, azacitidine), which are already first-line standard-of-care treatments for MDS. Multiple completed Phase 2 trials have explored ATO-based combination strategies, and a 2023 systematic review and component network meta-analysis (PMID 37908176) has synthesised the available evidence, while a 2025 retrospective RCT (PMID 40167011) provides the most recent clinical data. Active ongoing trials as of early 2026 — including oral ATO formulations (NCT06778187, NCT06670222) — indicate continued and growing research interest in this direction.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT02190695	Phase 2	Completed	92	Randomised study comparing Decitabine alone vs. Decitabine + Carboplatin vs. Decitabine + Arsenic in relapsed/refractory AML and MDS; includes a dedicated ATO arm — the highest-level direct randomised evidence for ATO in MDS
NCT00454480	Phase 2/3	Completed	2,000	Large-scale multi-arm treatment development programme for older AML and high-risk MDS patients; one of the largest completed haematology trials in this disease space; provides robust safety reference data
NCT00803530	Phase 2	Terminated	55	Prospective multicentre trial of ATO + Ascorbic Acid directly in MDS (n=55); provides meaningful efficacy and safety data despite early termination
NCT00251511	Phase 2	Terminated	60	ATO + Thalidomide in all IPSS risk groups of MDS; response assessed every 6 weeks; largest of the terminated ATO + immunomodulator trials in MDS
NCT00274820	Phase 2	Completed	15	TADA regimen (Thalidomide + ATO + Dexamethasone + Ascorbic Acid) in MDS/myeloproliferative overlap; fully completed with complete dataset available
NCT06778187	Phase 2	Recruiting	30	Oral ATO (Arsenol®) + Ascorbic Acid + low-intensity therapy in TP53-mutated AML, MDS, and CMML; launched February 2025 — demonstrates active ongoing interest including an oral formulation
NCT00274781	Phase 2	Completed	30	ATO + Gemtuzumab Ozogamicin (Mylotarg) in advanced MDS; fully completed Phase 2 providing ATO combination safety data
NCT00195104	Phase 1/2	Completed	87	ATO + Low-dose Cytarabine in high-risk MDS and poor-prognosis AML; completed with 87 patients, establishing dose tolerability and preliminary efficacy
NCT00093366	Phase 1/2	Completed	32	ATO + Etanercept (anti-TNF) in advanced MDS; completed with 32 patients, exploring the rationale of combining ATO with TNF pathway blockade
NCT06670222	Phase 1	Recruiting	24	Oral ATO dose-escalation in low-risk MDS failing ESAs and Luspatercept; launched July 2025 — targets a specific unmet need population where new options are urgently needed

Literature Evidence

PMID	Year	Type	Journal	Key Findings
37908176	2023	Meta-analysis	Hematology	Systematic review and component network meta-analysis of ATO-containing regimens specifically in MDS; synthesises efficacy and adverse event profiles across multiple combination strategies to identify the optimal combination
40167011	2025	RCT / Clinical Trial	Hematology	Decitabine + ATO in elderly high-risk MDS patients; most recent clinical evidence examining efficacy and safety of the DAC + ATO combination as a novel therapeutic approach
38816179	2024	Comparative Study	Immunopharmacology and Immunotoxicology	Comparative immunological changes following realgar (oral arsenic) vs. ATO treatment in a murine MDS model; characterises immunomodulatory mechanisms relevant to in vivo MDS
18282365	2007	Review	Clinical Lymphoma & Myeloma	Comprehensive review of ATO clinical data in leukemias and MDS; documents >80% CR rate in APL and summarises Phase 2 MDS trial outcomes
20425329	2010	Review	Current Hematologic Malignancy Reports	ATO as treatment for MDS: mechanistic review of proapoptotic, antiproliferative, and anti-angiogenic properties, with clinical trial outcome summary
20956016	2011	Phase 1/2 Trial	Leukemia Research	ATO + Low-dose Cytarabine in 49 previously untreated intermediate-2/high-risk MDS patients; 17% CR rate, manageable toxicity, provides direct efficacy benchmark
30898879	2019	Mechanistic Study	Journal of Investigative Medicine	Decitabine and ATO exhibit synergistic apoptosis in MDS cell lines (MUTZ-1, SKM-1) via endoplasmic reticulum stress pathway, providing preclinical mechanistic justification for the combination
22964015	2012	Mechanistic Study	Journal of Hematology & Oncology	ATO + Ascorbic Acid modulate BCL2 family gene expression in MDS patients’ bone marrow before and after treatment — in vivo mechanistic evidence from 12 clinical cases
16105982	2005	Mechanistic Study	Blood	NF-κB and FLIP in ATO-induced apoptosis in MDS: demonstrates differential NF-κB activity between MDS subtypes and establishes molecular rationale for ATO sensitivity in higher-risk disease
17920679	2008	Clinical Trial	Leukemia Research	ATO + All-trans Retinoic Acid + Thalidomide combination in higher-risk MDS; evaluates clinical efficacy and safety of a triple combination approach

Malaysia Market Information

The Malaysian National Pharmaceutical Regulatory Agency (NPRA) confirms 1 registered product for Arsenic Trioxide with market status 已上市 (Marketed). Detailed product-level records (authorisation number, brand name, dosage form, approved indication text) were not captured in the current data export. Clinicians should verify the full registration details, including the approved indication scope, directly via the NPRA official portal (bpfk.moh.gov.my) before any clinical application.

Cytotoxicity

Arsenic Trioxide is an antineoplastic agent with a proven indication in a haematological malignancy (APL). This section applies.

Item	Content
Cytotoxicity Classification	Conventional cytotoxic / Differentiation agent — metalloidal antineoplastic compound (arsenic-based); not a targeted kinase inhibitor or immunotherapy
Myelosuppression Risk	Moderate — in MDS patients with pre-existing cytopenias, transient worsening of blood counts may occur during treatment; leukocytosis and differentiation syndrome are well-recognised in APL use
Emetogenicity Classification	Low to moderate
Monitoring Items	CBC with differential (at least weekly during induction), serum electrolytes (potassium and magnesium must be corrected before initiation), liver function, renal function, 12-lead ECG with QTc interval measurement (mandatory — risk of fatal arrhythmia)
Handling Protection	Must follow cytotoxic drug handling regulations; standard chemotherapy preparation, administration, and disposal protocols are required

Safety Considerations

Please refer to the package insert for safety information.

Detailed warnings and contraindications were not available in this Evidence Pack. Key known safety concerns for ATO include: QTc prolongation (risk of torsades de pointes and potentially fatal ventricular arrhythmia — electrolyte correction before initiation is mandatory), APL differentiation syndrome (in the APL indication), and arsenic accumulation toxicity with prolonged exposure. In MDS patients who are often elderly with comorbidities, cardiac and renal monitoring is especially important. Full prescribing information must be reviewed before any clinical use.

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: A completed randomised Phase 2 study (NCT02190695, n=92), a 2023 systematic meta-analysis (PMID 37908176), and a 2025 retrospective RCT (PMID 40167011) provide Level L2 evidence that ATO — particularly in combination with decitabine — has clinically meaningful activity in MDS. The mechanistic link (NF-κB/Bcl-2/apoptosis pathway dysregulation in MDS) is well-established, and active trials with oral ATO formulations (as of 2025–2026) confirm sustained research interest. The drug is already marketed in Malaysia, lowering the regulatory barrier for structured clinical evaluation.

To proceed, the following is needed:

Safety documentation: Retrieve the full Malaysia or international prescribing information to confirm contraindications, QTc monitoring protocol, and drug interaction profile before any clinical planning
Regulatory scope confirmation: Verify whether the current Malaysia NPRA registration is limited to APL; if so, assess the feasibility of a compassionate use application or institutional clinical trial for MDS
Patient population selection: Prioritise adult high-risk MDS (IPSS intermediate-2 or high) as the initial target, where the combination of ATO + decitabine has the most supporting evidence and unmet need is greatest
Cardiac safety protocol: Establish a mandatory baseline and serial QTc monitoring plan, including electrolyte (K⁺, Mg²⁺) correction criteria, given the known arrhythmia risk
Evidence synthesis review: Review the 2023 meta-analysis (PMID 37908176) and the 2025 RCT (PMID 40167011) in detail to determine the preferred combination partner (decitabine vs. azacitidine), optimal dosing schedule, and response criteria
Subtype stratification note: TxGNN also flagged MDS subtypes (unclassified MDS, refractory cytopenia of childhood, aregenerative anemia) in the top 10 predictions; the mechanism and evidence reviewed here are most applicable to adult MDS broadly — paediatric and rare subtype applications require separate dedicated review
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.