Version July 2025
Cutaneous T-cell lymphoma, mycosis fungoides type: Topical: Apply a thin film once daily to affected areas of skin. In the clinical study, treatment was continued for 1 year and concurrent use of topical or systemic corticosteroids was not allowed (Ref).
There are no dosage adjustments provided in the manufacturer's labeling; however, based on the lack of systemic exposure, dosage adjustment is likely not necessary.
There are no dosage adjustments provided in the manufacturer's labeling; however, based on the lack of systemic exposure, dosage adjustment is likely not necessary.
Skin ulceration (any grade), blistering, or dermatitis (moderately severe-to-severe): Withhold treatment; upon improvement, may reinitiate treatment with a reduced frequency of once every 3 days; if every 3-day application is tolerated for at least 1 week, may increase to every other day for at least 1 week, then (if tolerated) may increase to once daily.
Refer to adult dosing.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.
>10%:
Dermatologic: Bacterial skin infection (11%), dermatitis (56%), pruritus (20%)
Hematologic & oncologic: Decreased hemoglobin (≤13%), decreased neutrophils (≤13%), decreased platelet count (≤13%)
1% to 10%: Dermatologic: Dermal ulcer (≤6%), skin blister (≤6%), skin hyperpigmentation (5%), skin neoplasm (nonmelanoma: 2%)
Postmarketing:
Dermatologic: Bullous rash (Goday 1990), Stevens-Johnson syndrome (Newman 1997), urticaria (Grunnet 1976)
Hypersensitivity: Nonimmune anaphylaxis (Grunnet 1976)
Known severe hypersensitivity to mechlorethamine or any component of the formulation.
Concerns related to adverse effects:
• Accidental exposure: Eye exposure may result in pain, burning, inflammation, photophobia, and blurred vision. Blindness and severe anterior eye injury (irreversible) may occur. If exposure to eye(s) occurs, promptly irrigate for at least 15 minutes with copious amounts of water, normal saline, or balanced salt ophthalmic irrigating solution; obtain immediate medical care, including ophthalmology consultation. Exposure to mucous membranes may cause pain, redness, and ulceration; may be severe. If mucosal contact occurs, irrigate promptly for at least 15 minutes with copious amounts of water and obtain medical consultation.
• Dermatitis: Dermatitis commonly occurs; may be moderately severe or severe. Symptoms include redness, swelling, itching, blistering, ulceration, and secondary skin infections. Facial, genitalia, anus and intertriginous skin areas are at increased risk for dermatitis.
• Hypersensitivity: Hypersensitivity reactions (including anaphylaxis) have occurred with topical mechlorethamine application.
• Secondary exposure: Avoid direct contact with mechlorethamine (other than intended treatment areas for the patient). Secondary exposure risks include dermatitis, mucosal injury, and secondary malignancies. To prevent secondary exposure, follow recommended application procedures.
• Secondary malignancy: In a clinical study, nonmelanoma skin cancers developed during or within 1 year following treatment. Some instances occurred in patients who had received previous treatments that were associated with nonmelanoma skin cancer. Nonmelanoma skin cancers may occur anywhere on the skin, including untreated areas.
Other warnings/precautions:
• Flammable gel: Mechlorethamine gel contains alcohol and is flammable; follow recommended application procedures and avoid fire, flame, and smoking until mechlorethamine has dried.
Valchlor 0.016% is equivalent to 0.02% mechlorethamine hydrochloride
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Gel, External:
Valchlor: 0.016% (60 g) [contains edetate (edta) disodium, isopropyl alcohol, menthol, propylene glycol]
No
Gel (Valchlor External)
0.016% (per gram): $117.98
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Gel, External:
Ledaga: 0.016% (60 g) [contains edetate (edta) disodium, isopropyl alcohol, menthol, propylene glycol]
Valchlor is only available through a specialty pharmacy; information regarding prescribing and access may be found at www.valchlor.com.
Topical: Apply a thin film topically to affected area. Apply immediately (or within 30 minutes) after removal from refrigerator; return to refrigerator promptly after each use. Apply to completely dry skin at least 4 hours before or 30 minutes after showering/washing. Allow treated area(s) to dry for 5 to 10 minutes after application before covering with clothing. May apply emollients (moisturizers) to treated area 2 hours before or 2 hours after mechlorethamine application. Do not use occlusive dressings over treatment areas. Avoid fire, flame, and smoking until mechlorethamine has dried.
Caregivers should wear nitrile gloves when applying to patients. Wash hands thoroughly with soap and water after handling/application. If accidental skin exposure occurs, wash thoroughly for at least 15 minutes with soap and water; remove any contaminated clothing.
Hazardous agent (NIOSH 2024 [table1]).
Use appropriate precautions for receiving, handling, storage, preparation, dispensing, transporting, administration, and disposal. Follow NIOSH and USP 800 recommendations and institution-specific policies/procedures for appropriate containment strategy (NIOSH 2023; NIOSH 2024; USP-NF 2020).
An FDA-approved patient medication guide, which is available with the product information and as follows, must be dispensed with this medication:
Valchlor: https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/202317s009lbl.pdf#page=10
Cutaneous T-cell lymphoma, mycosis fungoides-type: Topical treatment of stage IA and IB mycosis fungoides-type cutaneous T-cell lymphoma in patients who have received prior skin-directed therapy.
None known.
There are no known significant interactions.
Patients are advised not to become pregnant during topical mechlorethamine treatment. Patients who could become pregnant and patients with partners who could become pregnant should use a barrier method of contraception during therapy.
Based on the mechanism of action, case reports in humans, and data from animal reproduction studies, in utero exposure to topical mechlorethamine may cause fetal harm. There are case reports of major birth defects following maternal administration of systemic mechlorethamine.
It is not known if mechlorethamine is present in breast milk following topical application.
Due to the potential for serious adverse reactions in the breastfed infant following topical or systemic exposure from the mother's skin, the manufacturer recommends a decision be made to discontinue breastfeeding or to discontinue the drug, taking into account the importance of treatment to the mother.
Monitor for dermatologic toxicity (skin ulcers, blistering, dermatitis, secondary skin infections), and for signs/symptoms of nonmelanoma skin cancer (during treatment and after discontinuation) and/or hypersensitivity reactions.
Mechlorethamine is a nitrogen mustard alkylating agent which forms inter- and intra-strand DNA cross-links, resulting in inhibition of DNA synthesis. Topical application allows for skin-directed treatment while minimizing systemic nitrogen mustard exposure (Lessin 2013).
Absorption: Topical: None detected (Lessin 2013).
Distribution: Topical: No detectable systemic exposure in a clinical study (Lessin 2013).
