LEUSTATIN

What it is

Cladritab is a medicine containing cladribine, with each tablet containing 10 mg cladribine. Cladribine is a nucleoside analogue of deoxyadenosine. It leads to selective depletion of dividing and non-dividing T and B cells.

Approved indications

— Relapsing-remitting multiple sclerosis (RRMS) to reduce the frequency of clinical relapses and to delay the progression of physical disability.

Dosing overview

The recommended cumulative dose of Cladritab is 3.5 mg/kg body weight over 2 years, administered as 1 treatment course of 1.75 mg/kg per year. Each treatment course consists of 2 treatment weeks, one at the beginning of the first month and one at the beginning of the second month of the respective year. Each treatment week consists of 4 or 5 days on which a patient receives 10 mg or 20 mg (one or two tablets) as a single daily dose, depending on body weight. Following completion of the 2 treatment courses, no further cladribine treatment is required in years 3 and 4.

Key safety warnings

Cladribine can reduce the body's immune defence and may increase the likelihood of infections. Serious, severe, and opportunistic infections—including events with fatal outcome—have been observed with Cladritab treatment. The incidence of herpes zoster was increased in patients on cladribine. If lymphocyte counts drop below 200 cells/mm³, anti-herpes prophylaxis according to local standard practice should be considered during the time of grade 4 lymphopenia. In clinical studies, 20% to 25% of the patients treated with a cumulative dose of cladribine 3.5 mg/kg over 2 years developed transient grade 3 or 4 lymphopenia, with grade 4 lymphopenia seen in less than 1% of patients. The largest proportion of patients with grade 3 or 4 lymphopenia was seen 2 months after the first cladribine dose in each year. Liver injury, including serious cases, has been reported uncommonly in patients treated with Cladritab, especially in patients with a medical history of abnormal liver tests. Patients should have their serum aminotransferase, alkaline phosphatase, and total bilirubin levels assessed prior to initiation of each treatment course. Events of malignancies were observed more frequently in cladribine-treated patients (10 events in 3414 patient-years [0.29 events per 100 patient-years]) compared to patients who received placebo (3 events in 2022 patient-years [0.15 events per 100 patient-years]).

Contraindications

Cladritab therapy must not be initiated in patients with hypersensitivity to cladribine or to any of the tablet excipients, patients who are infected with HIV, patients with active chronic infections (tuberculosis, hepatitis), or immunocompromised patients, including patients receiving immunosuppressive or myelosuppressive therapy with agents such as cyclosporin, methotrexate, mitoxantrone, azathioprine, natalizumab, or chronic use of corticosteroids. Cladritab is contraindicated in patients with moderate or severe renal impairment (creatinine clearance <60 mL/min). Cladritab is contraindicated in pregnancy and breastfeeding.

PBS listing

Cladritab solution for intravenous infusion 10 mg in 10 mL single-use vial is listed on the PBS with streamlined restriction at an ex-manufacturer price of A$404.63.

Regulatory history

Cladritab received initial approval on 22 September 2025.