Mavenclad (Cladribine)

Mavenclad (cladribine) is a disease‑modifying therapy that targets the immune pathway involved in multiple sclerosis.

• Relapsing‑remitting multiple sclerosis: reduces annualized relapse rate and slows disability progression.
• Active secondary progressive multiple sclerosis: decreases disease activity and may delay progression.
• Clinically isolated syndrome with high conversion risk: may lower the likelihood of developing definitive multiple sclerosis.
• Overall multiple sclerosis disease activity: provides long‑term modulation of immune response to reduce new lesions.

• Cladribine is a purine nucleoside analog that enters lymphocytes and is phosphorylated to its active triphosphate form. The active metabolite incorporates into DNA, causing strand breaks and inhibiting DNA synthesis, which leads to selective depletion of B and T lymphocytes. This reduction of autoreactive lymphocytes diminishes the autoimmune attack on central nervous system myelin, providing a disease‑modifying effect in multiple sclerosis.

Cladribine may be associated with a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Lymphopenia: reduced lymphocyte count detected in routine blood work.
• Headache: mild to moderate head pain reported by some patients.
• Nausea: occasional feeling of stomach upset or urge to vomit.

Serious or Rare Side Effects

• Severe or prolonged lymphopenia with opportunistic infections: marked immune suppression leading to infections such as pneumonia or fungal disease.
• Reactivation of latent viruses (e.g., herpes zoster): shingles‑like eruptions may appear during or after treatment.
• Progressive multifocal leukoencephalopathy (PML): rare, potentially fatal brain infection linked to JC virus reactivation.

Before initiating therapy, several safety considerations should be observed.

• Monitor lymphocyte counts: baseline and periodic testing are required to detect depletion.
• Assess infection risk: avoid initiating therapy in patients with active infections.
• Vaccination: administer required live vaccines before treatment; avoid live vaccines during and after therapy.
• Pregnancy and breastfeeding: contraindicated or not recommended; discuss alternatives with a physician.
• Renal function: evaluate and adjust use in patients with severe renal impairment.
• Store at ambient temperature: keep tablets in the original container, protect from moisture and light.

Cladribine can interact with other medicines, necessitating careful review.

Major Interactions (Avoid)

• Concurrent use of other immunosuppressants: may increase risk of severe infection.
• Live vaccines: contraindicated during treatment and for several months after the last dose.
• Antiviral agents that rely on lymphocyte function: potential additive immunosuppression.

Moderate Interactions (Monitor Closely)

• CYP450 substrates: cladribine is not a strong inhibitor but monitor plasma levels of sensitive drugs.
• Non‑live vaccines: may have reduced efficacy; assess immune response.
• Hormonal contraceptives: no known interaction, but standard monitoring is advised.