Interferon α therapy for patients with essential thrombocythemia

Abstract

BACKGROUNDIn 1986, a Phase II trial of recombinant interferon‐α (IFN‐α) was initiated as therapy for patients with essential thrombocythemia (ET).METHODSPatients were treated with subcutaneous IFN‐α at a dose of 5 × 106 units/m2 daily. In responding patients, the therapy lasted at least 3 years.RESULTSTwenty‐three patients (14 females and 9 males; median age, 41 years; age range, 20–63 years) with a median platelet count of 1350 × 109/L were treated. After a median follow‐up of 174 months (14.5 years), 15 of 20 evaluable patients (75%) responded, including 14 patients who achieved a complete hematologic response (CHR) (6 of them with bone marrow remission) and 1 patient who demonstrated a partial response. The median time to response was 6 months (range, 0.5–36 months), and the median response duration was 48 months (range, 5–114 months). Seven patients who achieved a CHR and were taken off therapy after they completed 3 years of maintenance therapy sustained their response for a median of 28 months. No symptoms or signs of thrombosis or hemorrhage were observed in responding patients. Eleven of 14 patients (78%) who achieved a CHR developed a recurrence, and 2 of 5 patients with recurrences who were rechallenged with IFN‐α achieved a second response. The treatment was tolerated relatively well.CONCLUSIONSIFN‐α was safe and effective therapy for patients with ET, and the ability of IFN‐α to reverse disease pathology and possibly modify the clinical course of patients with ET warrants its investigation in larger, prospective trials. Cancer 2005. © 2005 American Cancer Society.

A Rare Case of Triple-Negative Essential Thrombocythemia in a Young Postsplenectomy Patient: A Diagnostic Challenge

“…Prevention of vascular events has been the main objective of therapy and continues to be extremely important in the management of patients with ET [18]. Low-dose aspirin and cytoreductive drugs can be administered for this purpose, and cytoreductive therapy with hydroxyurea [19], interferon alpha [20], or anagrelide [21] has been effective in preventing thrombotic episodes in high-risk patients.…”

Use of Interferon Alfa in the Treatment of Myeloproliferative Neoplasms: Perspectives and Review of the Literature

“…Molecular responses, as defined by decreases in mutant allele burden by 20-50% (minor), greater than 50% (partial), or to undetectable levels (complete), also occurred in 55% of ET and 19% of PV patients with JAK2 V617F mutations [35]. There is no evidence that interferon can improve overall survival and alter the biologic disease course, such as reducing transformation to myelofibrosis or leukemia; however, interferon can reduce incidence of venous thromboembolism (VTE) in high-risk ET and PV patients [35][36][37].…”

Interferon alpha therapy in essential thrombocythemia and polycythemia vera—a systematic review and meta-analysis

“… 49 , 54 Included single-arm studies achieved 12–19 points on the rating scale with the studies by Masarova et al, Saba et al, and Gisslinger et al scoring highest. 34 , 39 , 51 A detailed quality assessment for the individual studies and the subcategories of the Downs and Black checklist is provided in Supplemental Table 3 .…”

“…The rate of thromboembolic events was reported by 13 studies reporting outcomes for non-peg-IFN and peg-IFN treated ET patients ( Figure 4 A ). 20 , 21 , 23 , 25 , 27 , 30 , 31 , 35 , 38 , 39 , 42 , 46 The rate of thromboembolic complications was uniformly low at 1.2% per patient year (95% CI 0.3–2.2%; Cochran’s Q statistic: 10.5; p=0.57; I 2 statistic: 0%) for ET patients and was not statistically significantly different (p=0.68) between non-peg-IFN (1.1%, I 2 =10.2%) and peg-IFN (1.5%, I 2 =0%).…”