Interferon apha 2b for treating patients with JAK2V617F positive polycythemia vera and essential thrombocytosis

Cytoreductive therapy in younger adults with polycythemia vera: a meta-analysis of safety and outcomes

ABSTRACT

Cytoreductive therapy is not routinely recommended for younger patients with polycythemia vera (PV) due to concern that treatment toxicity may outweigh therapeutic benefits. However, no systematic data support this approach. To support objective risk/benefit assessment of cytoreductive drugs in patients with PV aged <60 years (PV<60), this systematic review and meta-analysis was conducted to evaluate toxicity and disease-related complications in PV<60 treated with interferon alfa (rIFN-α) or hydroxyurea (HU). A search of PubMed, Scopus, Web of Science and Embase identified 693 unique studies with relevant keywords, of which 14 met inclusion criteria and were selected for analysis. The weighted average age of patients treated with rIFN-α was 48 years (n = 744 patients; 12 studies) and for HU was 56 years (n = 1397; 8 studies). The weighted average duration of treatment for either drug was 4.5 years. Using a Bayesian hierarchical model, the pooled annual rate of discontinuation due to toxicity was 5.2% for patients receiving rIFN-α (n = 587; 95% confidence interval [CI], 2.2-8.2) and 3.6% for HU (n = 1097; CI, 1-6.2). The average complete hematologic response for rIFN-α and HU was 62% and 52%, respectively. Patients experienced thrombotic events at a pooled annual rate of 0.79% and 1.26%; secondary myelofibrosis at 1.06% and 1.62%; acute myeloid leukemia at 0.14% and 0.26%; and death at 0.87% and 2.65%, respectively. No treatment-related deaths were reported. With acceptable rates of nonfatal toxicity, cytoreductive treatment, particularly with disease-modifying rIFN-α, may benefit PV<60. Future randomized trials prioritizing inclusion of PV<60 are needed to establish a long-term benefit of early cytoreductive treatment in these patients.

Clinical outcomes of interferon therapy for polycythemia vera and essential thrombocythemia: a systematic review and meta-analysis

Interferon therapy has been used in clinical practice for more than three decades to treat polycythemia vera (PV) and essential thrombocythemia (ET). However, there has been no systematic investigation of its expected outcomes and potential risks. We performed a systematic review and single-arm meta-analysis to assess the clinical outcomes (hematological response, molecular response, vascular events, hematological transformation, and adverse events) after interferon therapy for patients with PV and ET. A systematic search identified 37 reports, including data from 1794 patients that were published before March 2021. The pooled overall hematological response (OHR) rate was 86%, with better OHR rates observed in studies using long-acting interferon (p < 0.001) and studies with younger patients (p = 0.038). The pooled overall molecular response rate was 48%, and inter-study heterogeneity was also related to patient age (p = 0.009). The overall incidence was 0.42/100 person-years for thrombosis, 0.01/100 person-years for hemorrhage, 0.21/100 person-years for myelofibrotic transformation, and 0.08/100 person-years for leukemic transformation. Compared with hydroxyurea, interferon produced a non-inferior hematological response and a superior molecular response. In conclusion, interferon therapy provided high rates of hematological and molecular response for patients with PV and ET and was associated with a favorable prognosis.

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

Data on the efficacy and safety of interferon (IFN)-α for the treatment of essential thrombocythemia (ET) and polycythemia vera (PV) are inconsistent. We conducted a systematic review and meta-analysis and searched MEDLINE and EMBASE via Ovid, Scopus, COCHRANE registry of clinical trials, and Web of Science from inception through 03/2019 for studies of pegylated IFN (peg-IFN) and non-pegylated IFN (non-peg-IFN) in PV and ET patients. Random-effects models were used to pool response rates for the primary outcome of overall response rate (ORR) defined as a composite of complete response, partial response, complete hematologic response (CHR) and partial hematologic response. Peg-IFN and non-peg-IFN were compared by meta-regression analyses. In total, 44 studies with 1359 patients (730 ET, 629 PV) were included. ORR were 80.6% (95% confidence interval: 76.6-84.1%, CHR: 59.0% [51.5%-66.1%]) and 76.7% (67.4-84.0%; CHR: 48.5% [37.8-59.4%]) for ET and PV patients, respectively. In meta-regression analyses results did not differ significantly for non-peg-IFN vs. peg-IFN. Annualized rates of thromboembolic complications and treatment discontinuation due to adverse events were low at 1.2% and 8.8% for ET and 0.5% and 6.5% for PV patients, respectively. Both peg-IFN and non-peg-IFN can be effective and safe long-term treatments for ET and PV.

Clinico-Epidemiological Profile of Patients with Polycythaemia Rubra Vera - a Five Year Experience from a Tertiary Care Center

BACKGROUND

Polycythaemia rubra vera (PV) is a Philadelphia chromosome negative myeloproliferative neoplasm characterized by increased red cell production, independent of the mechanisms that regulate normal erythropoiesis. The aim of this study was to analyze the clinico-epidemiological profile of Pakistani patients with PV.

MATERIALS AND METHODS

In this retrospective cross sectional study, 26 patients with PV were enrolled from January 2010 to December 2014. They were diagnosed based on WHO criteria.

RESULTS

The mean age was 53.4±9.31 years (range 36-72) and the male to female ratio was 2:1. Overall 30.7% of patients were asymptomatic. In symptomatic patients, major complaints were headache (30.8%), abdominal discomfort (23.1%), blurred vision (15.3%), pruritus (11.5%) and vascular incidents (11.5%). Physical examination revealed plethoric face and splenomegaly as predominant findings, detected in 34.6% and 30.7%, respectively, with the mean splenic span of 15.9±2.04cm. The mean hemoglobin was 18.1±1.9 g/dl with the mean hematocrit of 55.6±8.3%. The mean total leukocyte count was 12.8±7.1x109/l and the platelet count 511±341.9x109/l. Mean erythrocyte sedimentation rate was 3.5±1.22mm/hr. Serum lactate dehydrogenase, serum creatinine and uric acid were 552.7±309.2, 0.8±0.17 and 6.60±1.89 respectively.

CONCLUSIONS

PV in Pakistani patients, unlike in the West, is seen in a moderately young population. The disease is frequently seen in male gender and primarily patients present with symptoms related to hyperviscosity.

Somatic JAK-2 V617F Mutational Analysis in Polycythemia Rubra Vera: a Tertiary Care Center Experience

BACKGROUND

Polycythemia rubra vera (PV), being a primary polycythemia, is caused by neoplastic proliferation of erythroid, megakaryocytic and granulocytic lineages which result in panmyelosis. PV patients have a somatic acquired mutation in the Janus kinase (JAK2) pathway, rendering cell proliferation independent of the normal regulatory mechanisms that regulate erythropoiesis. The rational of this study was to determine the prevalence of the JAK-2 V617F mutation in Pakistani patients with PV.

MATERIALS AND METHODS

In this cross sectional study, 26 patients with PV were enrolled from January 2010 to December 2014. Patients were diagnosed based on WHO criteria for PV. All were screened for G-T point mutation (V617F) in the JAK2 gene on chromosome 9 by an allele specific PCR.

RESULTS

The mean age was 53.4±9.31 years (range 36-72) and the male to female ratio was 2:1. The frequency of JAK2 V617F positivity in our PV patients was found to be 92.3%. Overall 30.7% of patients were asymptomatic and remaining 69.3% presented with symptomatic disease. The mean hemoglobin was 18.1±1.9g/dl with the mean hematocrit of 55.6±8.3%. The mean total leukocyte count was 12.8±7.1x109/l and the platelet count was 511±341.9x109/l. A positive correlation of JAK2 V617F mutation was established with high TLC count (P=0.01). No correlation of JAK2 V617F could be established with age or gender (P>0.05).

CONCLUSIONS

The JAK2 V617F mutation frequency in our PV patients was similar to those reported internationally. Screening for the mutation in all suspected PV cases could be beneficial in differentiating patients with reactive and clonal erythrocytosis.

Clinico-Hematological Profile and Risk Stratification in Patients with Essential Thrombocythemia: Experience from Pakistan

BACKGROUND

Essential thrombocythemia (ET) is a Philadelphia chromosome-negative myeloproliferative neoplasm characterized by sustained thrombocytosis and megakaryocytic hyperplasia. It is an uncommon hematological malignancy which primarily affects elderly individuals. The rational of this study was to determine its clinico-hematological profile along with risk stratification in Pakistan patients.

MATERIALS AND METHODS

In this retrospective cross sectional study, 21 patients with ET were enrolled from January 2011 to December 2014. Data was analyzed with SPSS version 21.

RESULTS

The mean age was 56.7 ± 19.0 years (range 18-87) and the male to female ratio was 1:1.1. Of the total, 62% of patients were above 50 years of age. Overall 61.9% were diagnosed incidentally and were asymptomatic. In symptomatic patients, major complaints were weakness (19%); erythromelalgia (14.2%), transit ischemic attack (9.5%) and gastrointestinal bleed (4.7%). The mean hemoglobin count was 11.7 ± 2.4 g/dl with a total leukocyte count of 13.3 ± 8.1 x 10(9)/l and platelets count of 1188.8 ± 522.2 x 10(9)/l. Serum lactate dehydrogenase, serum creatinine and uric acid were 454.3 ± 127.8, 1.2 ± 0.5 and 7.4 ± 3.4 respectively. According to risk stratification, 57.1% were in high risk; 23.8% in intermediate risk while 19.1% in low risk group.

CONCLUSIONS

ET in our patients in Pakistan, unlike in the West, is seen in a relatively young population. Primarily patients were asymptomatic and risk stratification revealed predominance of high risk disease in our setting.

Acquired JAK-2 V617F Mutational Analysis in Pakistani Patients with Essential Thrombocythemia

BACKGROUND

Essential thrombocythemia (ET) is a clonal hemopoietic stem cell myeloproliferative neoplasm characterized by persistent thrombocytosis along with megakaryocytic hyperplasia. In the last decade following the identification of an acquired JAK2 V617F mutation, there has been acceleration in our understanding of this disease. The rational of this study was to determine the mutational profile of JAK2 V617F in Pakistan patients with ET.

MATERIALS AND METHODS

In this retrospective cross sectional study, 21 patients with ET were enrolled from January 2011 to December 2014. Patients were diagnosed based on WHO criteria for essential thrombocythemia. Complete blood count was done on an automated hematology analyzer, while JAK2 V617F expression was evaluated by polymerase chain reaction.

RESULTS

The mean age was 56.7±19.0 years (range 18-87) and the male to female ratio was 1:1.1. The frequency of JAK2 V617F positivity in our ET patients was found to be 61.9%. The mean hemoglobin was 11.7±2.4 g/dl with a total leukocyte count of 13.3±8.1x109/l and a platelet count of 1188±522x109/l. Positive correlations for JAK2 V617F mutation were established with high TLC count and raised LDH (P<0.05). No correlation of JAK2 V617F could be established with age and gender (P>0.05).

CONCLUSIONS

JAK2 V617F mutation frequency in our ET patients was similar to those reported previously. Screening for the mutation in all suspected essential thrombocythemia cases could be beneficial in differentiating patients with reactive and clonal thrombocytosis.