Rituximab in previously treated primary immune thrombocytopenia patients: evaluation of short- and long-term efficacy and safety

Real-world Experience of Rituximab in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is a relapsing-remitting disease often requiring more than one line of therapy. Rituximab is a recommended second-line therapy, but the real-world data on its efficacy and safety from resource constraint settings is limited. We aimed to analyze the safety and efficacy of rituximab in ITP. This is a single-center, retrospective study. This study was conducted at a tertiary care hospital in Northern India from 2005 to 2019. On audit of medical records, all patients of ITP (n-513) who had received rituximab (n-81) were screened for inclusion. Patients whose response assessment was not possible were excluded. Finally, 66 patients were analyzed using statistical packages of Python v3.7. The cumulative incidence of overall response on day 20 was 30.61%, and day 30 was 51.72%. The median time to response was 28 day (range 21-51 day). Cumulative incidence of complete response was 16.67%, and partial response 37.88%. After a median follow-up of 789 day (range 181-5260 day), the cumulative incidence of relapse was 30.32%, 36.12%, and 56.57% at 1, 2, and 5 years respectively. There was no effect of age, sex, duration of disease, lines of therapy received, and platelet count on either cumulative incidence of overall response or relapse. ANA positivity was significantly related to the better cumulative incidence of overall response (p = 0.012), but not with relapse. Infusion-related reactions were the commonest adverse event noted (n-4, grade ≥ 3 CTCAEv4). Rituximab and its generic version are safe and effective second line agent in ITP with a good overall response and sustained response.

Extended Small-Dose Platelet Transfusions in Multitransfused Hemato-Oncological Patients: A Single-Center Experience

BACKGROUND

Refractoriness to platelet transfusion, prevalent among 15-20% of hemato-oncological patients, is associated with multitransfusions and inferior outcomes. We evaluated the effectiveness of extended slow-dose transfusion (ESDT) in increasing platelet increments in multitransfused patients.

METHODS

Patients treated after the implementation of ESDT were compared with historical controls treated with standard single-donor platelet (SDP) transfusions. Cohorts of early and late recipients were assembled for comparison, i.e. the 8th or 9th and 11th platelet unit per patient, respectively. Patients in the ESDT group received transfusions equal to half an SDP unit, administered over 4 h. Effectiveness was defined as a higher corrected count increment (CCI) at 1, 12, and 24 h after transfusion.

RESULTS

In the early-recipients cohort, 24-h-posttransfusion increments were available for 29 ESDT patients and 6 standard patients, and did not differ significantly between the groups (p = 0.078). The 24-h-posttransfusion increment was available for 20 ESDT patients and 7 standard patients in the late-recipients cohort. The CCI was significantly higher in the ESDT group (p = 0.042). ABO compatibility improved the CCI (p = 0.01).

CONCLUSIONS

ESDT demonstrated slightly higher increments at 24 h after transfusion in late recipients, suggesting this could be a cost-effective approach for the treatment of thrombocytopenic multitransfused hemato-oncological patients.

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.

Materials and 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).

Conclusion:

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.