Cladribine with or without rituximab

In a phase II study, 68 patients with previously untreated hairy cell leukemia were randomly assigned to receive cladribine (0.15 mg/kg IV) on days 1 to 5, with eight weekly doses of rituximab either concurrently (starting on day 1) or delayed (starting after 6 months of cladribine treatment) if still positive with measurable residual disease (MRD) testing.[4][Level of evidence C3]

In a phase II study, 68 patients with previously untreated hairy cell leukemia were randomly assigned to receive cladribine (0.15 mg/kg IV) on days 1 to 5, with eight weekly doses of rituximab either concurrently (starting on day 1) or delayed (starting after 6 months of cladribine treatment) if still positive with measurable residual disease (MRD) testing.[4][Level of evidence C3]

With a median follow-up of 96 months, 94% of patients who received concurrent therapy were MRD-free, compared with 12% of patients who received delayed therapy.

In a phase II study, 68 patients with previously untreated hairy cell leukemia were randomly assigned to receive cladribine (0.15 mg/kg IV) on days 1 to 5, with eight weekly doses of rituximab either concurrently (starting on day 1) or delayed (starting after 6 months of cladribine treatment) if still positive with measurable residual disease (MRD) testing.[4][Level of evidence C3]

Although patients who underwent concurrent therapy had more need for platelet transfusions, they demonstrated higher neutrophil and platelet counts after 1 month.

In a phase II study, 68 patients with previously untreated hairy cell leukemia were randomly assigned to receive cladribine (0.15 mg/kg IV) on days 1 to 5, with eight weekly doses of rituximab either concurrently (starting on day 1) or delayed (starting after 6 months of cladribine treatment) if still positive with measurable residual disease (MRD) testing.[4][Level of evidence C3]

A retrospective case series reported a median progression-free survival (PFS) of 67 months in patients with relapsed disease who received a purine nucleoside analogue (usually cladribine) plus rituximab.[13][Level of evidence C2]

In a phase II study, 68 patients with previously untreated hairy cell leukemia were randomly assigned to receive cladribine (0.15 mg/kg IV) on days 1 to 5, with eight weekly doses of rituximab either concurrently (starting on day 1) or delayed (starting after 6 months of cladribine treatment) if still positive with measurable residual disease (MRD) testing.[4][Level of evidence C3]

A retrospective case series of nine patients with a histologic variation of hairy cell leukemia (HCL-v) reported an 88% complete response rate and 3-year PFS rate of 42% (95% confidence interval [CI], 1%–84%) after treatment with a purine nucleoside analogue (usually cladribine) plus rituximab.[14][Level of evidence C2]

Cladribine was given by daily subcutaneous injections or by daily 2-hour IV infusions for 5 to 7 days.[5,15-17][Level of evidence C3] Purine analogues should be avoided in cases of active infection or moderate to severe hepatic or renal impairment.

Cladribine was given by daily subcutaneous injections or by daily 2-hour IV infusions for 5 to 7 days.[5,15-17][Level of evidence C3] Purine analogues should be avoided in cases of active infection or moderate to severe hepatic or renal impairment.

The complete response rate was 50% to 80%.

Cladribine was given by daily subcutaneous injections or by daily 2-hour IV infusions for 5 to 7 days.[5,15-17][Level of evidence C3] Purine analogues should be avoided in cases of active infection or moderate to severe hepatic or renal impairment.

The overall response rate was 85% to 95%.

A National Cancer Institute group C protocol of 979 patients treated with cladribine reported lower response rates (i.e., 50% complete remission rate, 37% partial remission rate) compared with other studies.[18] Responses were durable in patients treated with a short course of cladribine, and patients who had a relapse often responded to re-treatment with cladribine.[2,13,19]

A retrospective review included 83 patients, aged 40 years and younger.[2]

A retrospective review included 83 patients, aged 40 years and younger.[2]

The median time to first relapse was 54 months for all responders, and the median overall survival (OS) was 21 years from diagnosis.

A retrospective review included 83 patients, aged 40 years and younger.[2]

Cladribine may cause fever and immunosuppression; documented infection was found in 33% of treated patients.