How it is administered

Cladribine is available as an intravenous (IV) infusion and as oral tablets (for other indications). For blood cancers like Hairy Cell Leukemia, it is most commonly given as a continuous intravenous infusion. The standard regimen is a single course given by continuous infusion for 7 consecutive days at a dose of 0.09 mg/kg/day. The medication must be diluted with 0.9% Sodium Chloride Injection and administered under the supervision of a healthcare professional experienced in cancer chemotherapy.

How it works

Cladribine is a synthetic antineoplastic (anti-cancer) agent that targets certain types of white blood cells, particularly lymphocytes and monocytes. It works by mimicking a natural building block of DNA, but with a small chemical change. Once inside the cell, cladribine is converted into its active form by cellular enzymes. This active form accumulates in cells with high levels of a specific enzyme, which are typically the cancerous lymphocytes.

The active cladribine disrupts the cell’s ability to repair and synthesize DNA, leading to cell death. This effect is unique because it targets both actively dividing and resting (quiescent) lymphocytes, making it effective against blood cancers where cancer cells may not always be dividing. By depleting these abnormal cells, cladribine helps restore normal blood cell counts and immune function.

Who Should take it

Cladribine is indicated for adults with active Hairy Cell Leukemia, a rare type of blood cancer. It is used when the disease is causing significant symptoms or low blood counts, such as anemia (low red blood cells), neutropenia (low white blood cells), or thrombocytopenia (low platelets).

While its main FDA-approved use is for Hairy Cell Leukemia, cladribine may sometimes be considered for other blood cancers or lymphoproliferative disorders under the guidance of a specialist. Patients should only receive cladribine if their doctor determines that the benefits outweigh the risks, especially if other treatments have not worked or are not suitable.

Who should not take it

Cladribine should not be taken by anyone who has had a previous allergic reaction to cladribine or any of its components. It is also not recommended for pregnant women, as it can cause harm to the unborn baby. Women of childbearing potential should use effective contraception during treatment.

Patients with active infections, especially those who are immunocompromised, should not start cladribine until the infection is under control. Live vaccines should not be given during treatment. Caution is needed in patients with kidney or liver problems, and it is not recommended for use in children, as safety and effectiveness have not been established.

Commonly used with

Cladribine is usually used as a single agent for Hairy Cell Leukemia. Supportive medications, such as antibiotics, antifungals, or antivirals, may be given to prevent or treat infections due to low white blood cell counts. Blood transfusions may be needed if anemia or low platelets occur.

It is important to avoid other drugs that suppress the immune system or bone marrow at the same time, unless specifically directed by your doctor.

Commonly tested with

Cladribine has been studied in combination with other chemotherapy agents, especially in high-risk or relapsed blood cancers. In research settings, it has been used with cyclophosphamide and total body irradiation as part of bone marrow transplant conditioning regimens. However, for Hairy Cell Leukemia and similar disorders, it is most commonly tested and used as a single agent.