DAPSONE is AN EFFECTIVE AGENT for REFRACTORY ITP: ANALYSIS of UK ADULT ITP REGISTRY.
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All Authors
Pedone, G.L.
Miah, H.
Miah, A.
Taylor, L.
Johns, S.
Hermans, J.
Nga, E.
Mushkbar, M.
Lester, W.
Simcox, D.
LTHT Author
Hill, Quentin
LTHT Department
Oncology
Haematology
Haematology
Non Medic
Publication Date
2024
Item Type
Conference Abstract
Language
Subject
ADULT , THROMBOCYTOPOENIA , CLINICAL TRIALS AS TOPIC , COHORT STUDIES , CONTROLLED CLINICAL TRIALS AS TOPIC , DRUG ADMINISTRATION ROUTES , DRUG THERAPY, COMBINATION , DRUG THERAPY , SUBSTANCE WITHDRAWAL SYNDROME , WOMEN , FOLLOW-UP-STUDIES , ADMINISTRATION, INTRAVENOUS , DRUG DOSAGE CALCULATIONS , MEN , BLOOD PLATELETS , RECURRENCE , DRUG-RELATED SIDE EFFECTS AND ADVERSE REACTIONS , BLOOD COMPONENT TRANSFUSION , DAPSONE , HAEMOGLOBINS
Subject Headings
Abstract
Background: Dapsone, an anti-inflammatory and immunomodulatory agent, has been used for over 30 years in treating immune thrombocytopenia ITP), however novel evidence-based therapies have relegated it to highly refractory cases. Aim(s): Evaluation of safety and efficacy of dapsone in a real-world cohort of refractory ITP patients from the UK adult ITP registry. Method(s): Analysis of data on dapsone efficacy in ITP patients was assessed for platelet responses at 1, 3, 6, and 12 months. Following outcome measures were used: response (R) (PLT 30-100x109/L), complete response (CR) (PLT > 100x109/L), overall response (OR) (R+CR), and loss of response (LoR) (PLT < 30x109/L following OR). Safety assessment was based on bleeding episodes, platelet transfusions, tranexamic acid use, and a decrease in haemoglobin for dapsone-induced haemolysis. Result(s): Fifty-two out of 5322 patients registered in the UK adult ITP registry were treated with a daily median dose of 100 (50-200) mg of dapsone. The median age was 54 (16-82) years, with a 2:1 female-to-male predominance. The cohort was heavily pre-treated with a median of 5 (R: 0-13) lines of therapy, including 15 (29%) splenectomised patients. The median time from ITP diagnosis to dapsone treatment was 41(R: 0-389) months. A sub-cohort of 23 patients with complete follow-up platelet counts was analysed in greater detail. Eleven (48%) had dapsone as a single agent. In 8 (35%) patients, dapsone was added to other ongoing ITP drugs. Eleven (48%) were commenced on additional ITP treatments after dapsone was introduced (R: 0-6). These 23 patients received dapsone for a median of 70 (R: 7-1296) days. Nineteen (83%) received a subsequent therapy line following dapsone discontinuation at a median of 97 (R: 31-862) days after dapsone initiation. Thirteen (57%) achieved OR during treatment, of whom 7 had R and 6 CR. Interestingly, 12 out of 13 achieved OR within one month of treatment, including 5 CRs. PLT counts at baseline, 1, 3, 6, and 12 months, increased from medians of 9 (R: 1-41) to 26 (R: 1-218), 22 (R: 2-238), 30 (R: 2-142), and 69 (R: 17-86) x109/L, respectively. Wilcoxon signed-rank test shows a significant difference in PLT counts (p < 0.01). Five out of 13 (38%) responders maintained an OR after 6 months, and 2 (15%) after 12 months, while 11 (85%) experienced a LoR. Responders, when compared to non-responders, received fewer prior treatments, with a median of 3 (R: 0-9) vs. 6 (R: 2-11) lines of treatment, less concomitant treatments (0 (R: 0-2) vs. 0,5 (R: 0-1)), a lower dose of dapsone (50 (R: 50-100) vs. 100 (R: 50-100) mg), and fewer subsequent therapies (1 (R: 0-8) vs. 3,5 (R: 0-10)), had fewer relapses, and started dapsone earlier (17 (R: 0-231) vs. 58 (R: 3-355) months from diagnosis). No PLT transfusions or TXA were needed during dapsone treatment. The drug had a good safety profile, with no reported haemolytic events and stable haemoglobin. Summary/Conclusion: Dapsone was shown to be a safe drug with an overall response rate of 57% in a mainly refractory cohort of patients. This is not inferior to several novel drugs and should be considered an effective option in the management of ITP, even when refractory.
Journal
HemaSphere