Mechlorethamine
| Evidence Level: L3 | Predicted Indications: 3 |
Table of Contents
- Mechlorethamine
- Mechlorethamine: From Cutaneous T-Cell Lymphoma (Mycosis Fungoides) to Lymph Node Cancer
Mechlorethamine: From Cutaneous T-Cell Lymphoma (Mycosis Fungoides) to Lymph Node Cancer
One-Sentence Summary
Mechlorethamine is a nitrogen mustard chemotherapy drug, marketed in the US as a topical gel (VALCHLOR) and used for skin-based T-cell lymphoma (mycosis fungoides). The TxGNN model predicts it may be effective for lymph node cancer (lymphoma). Support is mostly historical: about 20 publications, including older trials of mechlorethamine-containing regimens such as MOPP in Hodgkin lymphoma. None of the registered clinical trials tests mechlorethamine directly.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Mycosis fungoides-type cutaneous T-cell lymphoma (the FDA license record supplied has no indication text; this is inferred from the product and the cited literature) |
| Predicted New Indication | Lymph node cancer |
| TxGNN Prediction Score | 99.43% |
| Evidence Level | L3 |
| US Market Status | ✓ Marketed |
| Number of NDAs | 1 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism-of-action data were not available in the source record. The following is based on the known class of the drug.
Mechlorethamine is a bifunctional nitrogen mustard alkylating agent. It forms DNA interstrand crosslinks, which trigger cell death (apoptosis) in rapidly dividing lymphoid cells. The topical gel targets skin-homing malignant T cells in mycosis fungoides.
The original and predicted indications are both lymphoid malignancies, so the mechanistic fit is direct. Historically, intravenous mechlorethamine was the “M” in the MOPP regimen (mechlorethamine, vincristine, procarbazine, prednisone) for Hodgkin lymphoma. Related alkylators such as bendamustine and cyclophosphamide are used in indolent B-cell lymphomas, including follicular lymphoma.
The marketed product is a topical gel for skin disease, not a systemic formulation. The prediction therefore rests on class-level plausibility and old intravenous regimens, not on evidence for the current product in nodal disease.
Clinical Trial Evidence
Over 40 trials are linked to this prediction. None tests mechlorethamine directly. The table lists the most relevant ones, and only the first offers class-level support.
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT00974233 | Phase 2 | Completed | 34 | Bendamustine (a nitrogen mustard-related alkylator) plus rituximab, then lenalidomide maintenance, in relapsed/refractory CLL/SLL |
| NCT02005471 | Phase 3 | Completed | 389 | Venetoclax + rituximab vs bendamustine + rituximab in relapsed/refractory CLL |
| NCT02162771 | Phase 3 | Completed | 140 | Rituximab biosimilar CT-P10 vs Rituxan, each with CVP, in advanced follicular lymphoma |
| NCT00345865 | Phase 2 | Completed | 473 | Autologous stem cell transplant with rituximab in lymphoma |
| NCT01889069 | Phase 3 | Completed | 159 | Subcutaneous rituximab with chemotherapy in DLBCL or follicular lymphoma |
| NCT00911183 | Phase 2 | Completed | 67 | R-CHOP-type therapy in frail elderly patients with DLBCL |
| NCT00006436 | Phase 2 | Completed | 68 | Short-course EPOCH-rituximab in HIV-associated lymphoma |
| NCT01008462 | Phase 2 | Completed | 16 | Sequential autologous and haploidentical transplant in high-risk lymphoma, myeloma or CLL |
| NCT00924326 | Phase 1/2 | Completed | 43 | Anti-CD19 CAR T cells in B-cell lymphoma (unrelated mechanism) |
| NCT03515798 | Phase 2 | Active, not recruiting | 52 | Pembrolizumab with chemotherapy in inflammatory breast cancer (disease-term match only) |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 7509381 | 1994 | RCT | J Clin Oncol | MOPP vs alternating MOPP/ABVD in stage IIIB-IV Hodgkin disease |
| 3352775 | 1988 | Comparative trial | NCI Monogr | EORTC H5 study: total nodal irradiation vs mantle irradiation plus MOPP in stage I-II Hodgkin disease |
| 35393251 | 2022 | Cohort | Clin Lymphoma Myeloma Leuk | Chlormethine/mechlorethamine 0.016% gel as maintenance in mycosis fungoides patients in remission |
| 6809030 | 1982 | Clinical series | Br J Dermatol | Outcomes in 92 cutaneous T-cell lymphoma patients, including topical mechlorethamine |
| 10473086 | 1999 | Mechanism study | Clin Cancer Res | O6-alkylguanine-DNA alkyltransferase in CTCL and its implications for alkylating-agent sensitivity |
| 2436740 | 1987 | Clinical series | Cancer | Six MOPP courses with or without radiotherapy in 37 children with Hodgkin disease |
| 24438970 | 2014 | Review | J Am Acad Dermatol | Prognosis and management of mycosis fungoides and Sézary syndrome |
| 31894937 | 2020 | Review | Am Fam Physician | Overview of lymphoma diagnosis and treatment |
| 21189660 | 2010 | Clinical study | Clin Lymphoma Myeloma Leuk | Bendamustine, a mechlorethamine-related alkylator, gave durable responses in rituximab-refractory indolent NHL |
| 15067795 | 2004 | Case series | J Ky Med Assoc | Outcomes of 32 pediatric Hodgkin disease patients treated 1981-1992 |
US Market Information
| Authorization Number | Product Name | Dosage Form | Manufacturer |
|---|---|---|---|
| NDA202317 | VALCHLOR | Gel (topical) | Helsinn Therapeutics (U.S.), Inc. |
Cytotoxicity
| Item | Content |
|---|---|
| Cytotoxicity Classification | Conventional cytotoxic (nitrogen mustard alkylating agent) |
| Myelosuppression Risk | High with systemic (intravenous) use. Lower with topical use, which has limited systemic exposure. |
| Emetogenicity Classification | High with intravenous use. Low with topical use. |
| Monitoring Items | CBC with differential, liver and renal function. For topical use, also monitor skin reactions. |
| Handling Protection | Follow cytotoxic drug handling regulations, including avoiding direct skin contact |
Safety Considerations
Please refer to the package insert for safety information.
Conclusion and Next Steps
Decision: Hold
Rationale: The mechanistic fit and the historical MOPP data are plausible, but no registered trial tests mechlorethamine in lymph node cancer. The marketed product is a topical gel, so systemic nodal disease would need a different route, and the historical intravenous formulation is not the current product. The evidence pack itself rates this a research question.
To proceed, the following is needed:
- FDA package insert data on warnings, contraindications and approved indication
- Mechanism-of-action data from DrugBank
- A route and formulation strategy, since the current product is a topical gel
- A comparison against current standard-of-care regimens, given that MOPP has largely been replaced
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.