Long-Term Outcomes Of Splenectomy-Sparing Therapies For Immune Thrombocytopenia

Anti-Rh(D) (Cooper Blood 2002), rituximab (Godeau Blood 2008), and dapsone (Sharma ASH 2006) have been shown to be splenectomy-sparing agents for the treatment of immune thrombocytopenia (ITP). In these studies, patients treated with anti-Rh(D) and rituximab were followed for 2 years; patients were treated with dapsone for 6 to 48 months.

To determine long-term outcomes in unsplenectomized patients with ITP treated with anti-Rh(D), rituximab, or dapsone.

Institutional Review Board approval was obtained. The charts of 52 consecutive patients with ITP followed in a hematology practice between 07/01/03 and 06/30/13 were reviewed. Response was defined as a platelet count (PLT) > 100,000/µL. Relapse was defined as PLT < 30,000/µL.

Twenty-one patients have been treated with anti-Rh(D), rituximab, or dapsone. Some patients treated with anti-Rh(D) or rituximab received brief concurrent steroids. For the entire cohort the mean duration of ITP was 3.50 years (y), range 0.008 to 19 y and the mean duration of follow-up was 3.84 y, range 0.10 to 8.81 y. Among 16 patients who received anti-Rh(D), 85% responded to the initial infusion. Among the 10 responders who have had follow-up exceeding 1 year, 4 have had a sustained response following the first infusion (mean follow-up duration 3.35 y, range 2.66 y to 5.98 y; six have relapsed, all have responded to retreatment. Among 7 patients who received rituximab, 71% responded to the initial treatment. All 5 responders have had follow-up exceeding 1 year, among whom 2 have had a sustained response following the first infusion (mean follow-up duration 2.24 y, range 2.19 y to 6.67 y); three have relapsed, all have responded to retreatment. Among 3 patients who received dapsone, 66.7% responded; the response is partial in 1 patient with PLT 50,000/µL (mean follow-up duration 3.94 y, range 0.11 y to 8 y). Toxicities have included: with anti-Rh(D) 1 case each of grade II uterine pain, grade II chills, and grade II non-cardiac chest pain; with rituximab 1 case of grade II back pain. Therapeutic switches have included 2 cases of anti-Rh(D) to rituximab and 1 case each of anti-Rh(D) to rituximab to dapsone, anti-Rh(D) to rituximab to dexamethasone, anti-Rh(D) to romiplostim, and dapsone to rituximab. No patients have undergone splenectomy.

Anti-Rh(D), rituximab, and dapsone are splenectomy-sparing therapies for ITP over an extended period. For patients treated with anti-Rh(D) or rituximab who relapse, retreatment is effective.

Off Label Use: Rituximab and dapsone therapies of ITP.