Changes in peripheral blood lymphocytes in polycythemia vera and essential thrombocythemia patients treated with pegylated-interferon alpha and correlation with JAK2
                     V617F allelic burden

Abstract Introduction: It has been previously reported that pegylated interferon alpha-2a can induce hematologic and molecular responses in patients with essential thrombocythemia "ET" and polycythemia vera "PV", but the follow up in these studies were relatively short. Objective: We present longer-term efficacy and safety results of a prospective phase II study of pegylated interferon alpha-2a in patients with ET and PV after a median follow up of 82.5 months (range, 8-107). Methods: Patients with a diagnosis of ET or PV, in a need of therapy, either newly diagnosed or previously treated, were eligible for this study. Median interferon starting dose of 180 mcg/week SQ (range, 450-90; 39% started on 90mcg/week) was modified in majority of the patients based on toxicity or lack of efficacy. Clinical and molecular responses were assessed every 3 to 6 months. Results: Among 83 enrolled patients (43 PV, 40 ET), 32 patients (39%) are still on study (but in 8 therapy is on hold: 5 due to toxicity, and 3 for financial reasons). Median age was 53 years (range, 19-78). Overall 37% of patients did not receive prior cytoreductive treatment. The overall median exposure to therapy was 87 months (range, 58-107) and was no different for patients still enrolled on the study and those who stopped study participation. Nine (28%) patients still on study are currently on a dose equal or higher than 90 mcg/week and 15 (47%) are on dose equal or smaller than 45mcg/week. JAK2 status or allele burden had no impact on achievement of response (clinical or molecular), time to response or duration of therapy. 55 of 59 (71%) JAK2V617F positive patients were evaluable for molecular response (Figure); 8 patients carried CARL mutation, 3 carried MPL and in 13 were triple negative. Median duration of hematologic and molecular response was 66 and 53 months, respectively; and directly correlated with treatment length and type of response (CMR had the longest duration of response). Overall yearly discontinuation rate were gradually decreasing for first 5 years, from 17% to 5%, and slowly increasing afterward to 10%. Of the 51 patients not on the study anymore, 27 (35% of the total) discontinued therapy primarily due to treatment toxicity. New late (≥24 months from start of therapy) G3/4 toxicity occurred in 17% of patients. Among patients in complete hematologic response treatment failure due to vascular adverse event or disease transformation was seen in 5 patients each. Three patients died on study (not related to therapy or disease), and 8 after stopping participation. Mean changes in allele burden over time in JAK2 positive patients are depicted in figure. Conclusions: Although pegylated interferon alpha-2a can induce significant hematologic and molecular responses; toxicity still limits its use over longer period of time and loss of response or transformation is encountered. Table.ResponseCharacteristicsFirst responseLast responseHem Resp, N. of patients (No), (%)CHR62 (76)25 (40)aPHR4 (5)1 (25)ORR66 (79)26 (39)aMol Resp, No, (%)CMR10 (18)9 (90)PMR20 (36)5 (25)*mMR5 (9)2 (40)ORR35 (74)16 (46)SafetyAny gradeGrade≥3Overall Adverse Events (AE), No, (%)any AE83 (100)57 (67)recurrent AE74 (89)13 (16)AE subtypes, No, (%)musculoskeletal73 (88)6 (8)neurological53 (64)2 (4)psychiatric38 (46)4 (11)gastrointestinal54 (65)11 (20)LFT elevation27 (33)5 (18)skin18 (22)2 (11)infection/fever26 (31)3 (12)respiratory23 (28)2 (9)cardiovascular13 (16)3 (23)metabolic16 (19)2 (13)neutropenia37 (45)21 (57)thrombocytopenia18 (22)a1 (6)anemia36 (43)1 (3)Autoimmune toxicity, No, (%)hepatitis1 (2.5)CNS vasculitis1 (2.5)lupus nephritis1 (2.3)Sjogren sy & dermatitis1 (2.5)Vascular AE (TEE/bleeding),Unprovoked6 (7)5 (83)No, (%)Provoked4 (5)3 (75)Disease transformation, No, (%)Myelofibrosis6 (7)AML1 (1)Safety over ≥24 months**Any gradeGrade≥3New AE, No (%)3th year10 (17)4 (40)4th year6 (11)4 (67)5th year5 (10)1 (20)≥ 6th year10 (24)1 (10)**Effective sample size for patients on therapy/year: Initial number of patients at risk at the beginning of period minus half of patients censored during that period*% calculated from 19 patientsastatistically significant differences by Fisher's exact testAbbr. CMR= complete molecular remission (undetectable JAK2 allele burden), PMR= partial molecular remission (>50% decrease in allele burden), mMR= minor molecular remission (20-49% decrease in allele burden) Figure 1. Figure 1. Disclosures Off Label Use: Pegylated Interferon alfa-2a used for patients with essential thrombocythemia and polycythemia vera. Cortes:Novartis: Consultancy, Research Funding; BerGenBio AS: Research Funding; Teva: Research Funding; BMS: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Astellas: Consultancy, Research Funding; Ambit: Consultancy, Research Funding; Arog: Research Funding; Celator: Research Funding; Jenssen: Consultancy. Konopleva:Novartis: Research Funding; AbbVie: Research Funding; Stemline: Research Funding; Calithera: Research Funding; Threshold: Research Funding.

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Pilot study of pegylated interferon-alpha 2b in patients with essential thrombocythemia

Cancer Chemotherapy and Pharmacology ◽

10.1007/s00280-002-0533-4 ◽

2003 ◽

Vol 51 (1) ◽

pp. 81-86 ◽

Cited By ~ 32

Author(s):

Yesid Alvarado ◽

Jorge Cortes ◽

Srdan Verstovsek ◽

Deborah Thomas ◽

Stephan Faderl ◽

...

Keyword(s):

Pilot Study ◽

Interferon Alpha ◽

Essential Thrombocythemia ◽

Pegylated Interferon ◽

Pegylated Interferon Alpha ◽

Interferon Alpha 2B

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Outcome of Pregnancy in the Era of Pegylated Interferon Alpha 2a in Females with Essential Thrombocythemia: An Experience from Qatar

Case Reports in Oncology ◽

10.1159/000506447 ◽

2020 ◽

Vol 13 (1) ◽

pp. 336-340

Author(s):

Mohammad Abu-Tineh ◽

Nancy Kassem ◽

Mohammad Abdul-Jaber Abdulla ◽

Omar Mohammad Ismail ◽

Rola Ghasoub ◽

...

Keyword(s):

Interferon Alpha ◽

Essential Thrombocythemia ◽

Myeloproliferative Neoplasms ◽

Pegylated Interferon ◽

Myelogenous Leukemia ◽

Hematopoietic Stem ◽

Pegylated Interferon Alpha ◽

Pregnant Females ◽

Increased Risk ◽

Hemorrhagic Complications

Myeloproliferative neoplasms are a diversified group of diseases of the hematopoietic stem cell, such as essential thrombocythemia (ET) and polycythemia vera. They are mainly caused by mutations in the following genes: JAK2, CALR, and MPL. All carry an increased risk to transform into acute leukemia or chronic myelogenous leukemia along with thrombosis and hemorrhagic complications. Treatment of such disorders during pregnancy is a challenging footstep, given the high risk of complications for both the mother and the fetus. Here, we report about two pregnant females with ET that has been treated with pegylated interferon alpha with safe and effective outcome.

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Pegifna Promotes Proliferation and Myeloid Differentiation In Human Hematopoietic Progenitors In Patients With Polycythemia Vera and Essential Thrombocythemia

Blood ◽

10.1182/blood.v122.21.2843.2843 ◽

2013 ◽

Vol 122 (21) ◽

pp. 2843-2843

Author(s):

Katherine King ◽

Sabina Swierczek ◽

Katie Matatall ◽

Kimberly Hickman ◽

Margaret A. Goodell ◽

...

Keyword(s):

Bone Marrow ◽

Cell Death ◽

Polycythemia Vera ◽

Essential Thrombocythemia ◽

Myeloproliferative Neoplasms ◽

Pegylated Interferon ◽

Hematopoietic Stem ◽

Financial Compensation ◽

Specific Differentiation ◽

Allelic Burden

Abstract The myeloproliferative neoplasms, polycythemia vera (PV) and essential thrombocythemia (ET), are characterized by clonal hematopoiesis that is often associated with a JAK2V617F mutation, although this does not appear to be a disease-initiating event. Treatment of PV and ET with pegylated interferon-alpha (pegInfα) has been shown to lead to hematological remission, a decrease in the JAK2V617F allelic burden in many cases, and even a reversion to polyclonal hematopoiesis. Despite promising therapeutic results, the mechanism of pegInfα-induced remission remains elusive. There are several potential mechanisms through which pegInfα may be acting, which include stimulating the immune system in order to more effectively suppress the aberrant PV clones, enhancing the activation of normal hematopoietic stem cells (HSCs), or by selectively suppressing the mutant clones. It has been previously reported that PV patients on pegInfα have an increased number of CD4+CD25+Foxp3+ T regulatory cells (Tregs) in the peripheral blood as compared to untreated or hydroxyurea treated patients (Riley Blood, 2011), which suggests that PegIFNa maybe altering immunity against the mutated clone. However, we have found that interferon treatment leads to increased proliferation of HSCs and myeloid-specific differentiation in mice (Baldridge Nature, 2010). If this finding is also true in humans, it suggests the return to polyclonality after pegInfα could also involve an increase in normal HSC proliferation. In order to address this question, we are studying the effects of pegInfα treatment on the Tregs and HSCs of PV and EV patients, when compared to hydroxyurea or untreated patients. Previously we showed that pegInfα treatment reduced the JAK2V617F allelic burden in 17 out of 32 patients. Of the 13 female patients for which clonality could be assessed, one developed polyclonal hematopoiesis with three-fold reduction of JAK2V617F allelic burden, but one developed polyclonal hematopoiesis during therapy despite no reduction in the JAK2V617F allelic burden, suggesting that pegInfα treatment is able to affect both pre-JAK2V617F clones and JAK2V617F-positive PV clones. We have now assessed changes in the HSC population in response to pegInfα treatment. Upon analysis of bone marrow samples from these same pegInfα or hydroxyurea treated patients, we found that the number of HSCs (CD45+CD34+CD38-) was increased in patients treated with pegInfα. Further we saw a decrease in the percent of quiescent HSCs in the pegInfα treated samples, measured by the percentage of cells in G0, suggesting a more actively proliferating HSC population. In agreement with these data, our RNA analysis of the HSCs showed an increase in the expression of cell cycle genes in response to short-term pegInfα treatment. In addition to this apparent increase in HSC proliferation, we also saw an increase in the number of colonies formed in methocult media from the bone marrow samples of the pegInfα treated patients, suggesting an increase in myeloid specific differentiation. When we analyzed the RNA of patients who had received long-term pegInfα treatment, we saw a transcriptional profile that was indicative of cell death. Taken together, these data suggest a model in which pegInfα treatment is allowing for a return to polyclonal hematopoiesis by inducing cell division and differentiation of normal HSCs, while suppressing the pre-JAK2V617F or JAK2V617F-positive PV and ET clones, possibly by promoting apoptosis or inducing an immune-mediated cell death. Our findings do not exclude other potential mechanisms for salutary effects of pegInfα for treatment of PV and ET (see accompanying abstract by Swierczek et al). Disclosures: Swierczek: University of Utah: No financial compensation , No financial compensation Patents & Royalties.

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