Rituximab Therapy in Adults with Refractory Symptomatic Immune Thrombocytopenia: Long-Term Follow-Up of 15 Cases.
OBJECTIVE
This paper prospectively evaluates the long-term follow-up [mean ± standard deviation (SD) duration: 89.7±19.4 months] data of 15 patients (13 females and 2 males) with refractory symptomatic immune thrombocytopenia (ITP) treated with rituximab.


METHODS
Rituximab was administered at 375 mg/m2 weekly for a total of 4 doses. Complete response (CR) was defined as a platelet count of ≥100,000/mm3 and partial response (PR) as a platelet count of ≥30,000/mm3 but less than 100,000/mm3. Early response (ER) and late response (LR) were defined as response within 42 days and after 42 days of initiation of rituximab therapy, respectively. Sustained response (SR) was defined as response lasting for at least 6 months.


RESULTS
Mean age (±SD) at the start of rituximab was 46.6±11.3 years. Mean platelet count (±SD) prior to rituximab treatment was 17,400±8878/mm3. The mean time (±SD) between rituximab therapy and response to rituximab in early responders and late responders was 1.8±1.3 weeks and 10±2.8 weeks, respectively. Mean durations (±SD) of ER and LR were 51±47.2 months and 6±4.2 months, respectively. Seven of the 15 patients (46.7%) showed an initial response to rituximab (5 ER and 2 LR). The rate of SR over 6 months was 26.7% (4/15). Among the responders to rituximab, 3 (3/7, 42.9%) maintained their response 1 year after rituximab treatment and 2 (2/7, 28.6%) had ongoing response 5 years after initiation of rituximab. Two of the 7 patients (28.6%) still maintained their response 98 months after initiation of rituximab. All 5 initial responders with subsequent relapse achieved response from subsequent treatment modalities (3 CR, 2 PR).


CONCLUSIONS
Our data confirm, over a long period of observation, that rituximab is safe and effective in the management of patients with chronic refractory primary ITP.
Bakırköy Sadi Konuk Training and Research Hospital, Clinic of Hematology, İstanbul, Turkey Phone: +90 212 414 71 71 E-mail: drfehmi_hindi@yahoo.com.
Fehmi
F
Hindilerden
İpek
İ
Yönal-Hindilerden
Mustafa Nuri
MN
Yenerel
Meliha
M
Nalçacı
Reyhan
R
Diz-Küçükkaya
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011446:Prospective Studies; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000188:drug therapy* / Q000401:mortality; D012008:Recurrence; D012074:Remission Induction; D000069283:Rituximab / Q000627:therapeutic use*; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D000069283:Rituximab