Frontline cytoreductive therapy

In an analysis of 51 patients from the PSVG-08 study, the use of hydroxyurea, along with phlebotomy as needed, significantly reduced the risk of thrombosis compared with 134 patients treated with phlebotomy alone from the PSVG-01 study.[19]

In an analysis of 51 patients from the PSVG-08 study, the use of hydroxyurea, along with phlebotomy as needed, significantly reduced the risk of thrombosis compared with 134 patients treated with phlebotomy alone from the PSVG-01 study.[19]

During the first 7.25 years of observation, there were fewer thrombotic events in patients who received hydroxyurea (9.8%) compared with those who received phlebotomy alone (32.8%) (P = .18). There was no difference in the incidence of leukemic transformation between the two groups at that time point.

In an analysis of 51 patients from the PSVG-08 study, the use of hydroxyurea, along with phlebotomy as needed, significantly reduced the risk of thrombosis compared with 134 patients treated with phlebotomy alone from the PSVG-01 study.[19]

With further follow-up (median, 8.6 years; maximum, 15.3 years), leukemic transformation occurred in three patients who received hydroxyurea (5.9%) and two patients who received phlebotomy alone (1.5%) (P = .25). There was no significant difference in the incidence of post-PV myelofibrosis or overall survival between the two groups.[19][Level of evidence C3]

The randomized phase III MPN-RC 112 study (NCT01259856) included 87 patients with high-risk PV. Patients were randomly assigned to receive either hydroxyurea or pegylated interferon alfa.[20]

The randomized phase III MPN-RC 112 study (NCT01259856) included 87 patients with high-risk PV. Patients were randomly assigned to receive either hydroxyurea or pegylated interferon alfa.[20]

The complete response rates at 12 months were similar between patients who received hydroxyurea or pegylated interferon alfa (30% vs. 28%, respectively).[20][Level of evidence A3]

The randomized phase III MPN-RC 112 study (NCT01259856) included 87 patients with high-risk PV. Patients were randomly assigned to receive either hydroxyurea or pegylated interferon alfa.[20]

Thrombotic events and disease progression were infrequent in both arms, whereas grade 3 or 4 adverse events were more frequent for patients who received pegylated interferon alfa (46% vs. 28%).

The PROUD-PV study (NCT01949805) randomly assigned 257 patients with an indication for cytoreduction to receive either ropeginterferon alfa-2B or hydroxyurea. Patients could have previously received hydroxyurea for up to 3 years, but with suboptimal response or intolerance. After 1 year, patients could choose to continue study treatment in the CONTINUATION-PV trial (NCT02218047): patients either continued to receive ropeginterferon alfa-2B or received best-available treatment (hydroxyurea or another standard first-line treatment).[13]

The PROUD-PV study (NCT01949805) randomly assigned 257 patients with an indication for cytoreduction to receive either ropeginterferon alfa-2B or hydroxyurea. Patients could have previously received hydroxyurea for up to 3 years, but with suboptimal response or intolerance. After 1 year, patients could choose to continue study treatment in the CONTINUATION-PV trial (NCT02218047): patients either continued to receive ropeginterferon alfa-2B or received best-available treatment (hydroxyurea or another standard first-line treatment).[13]

In PROUD-PV, the 12-month complete hematological response rates were similar between the treatment groups (43% for ropeginterferon alfa-2B vs. 46% for hydroxyurea; P = .63).

The PROUD-PV study (NCT01949805) randomly assigned 257 patients with an indication for cytoreduction to receive either ropeginterferon alfa-2B or hydroxyurea. Patients could have previously received hydroxyurea for up to 3 years, but with suboptimal response or intolerance. After 1 year, patients could choose to continue study treatment in the CONTINUATION-PV trial (NCT02218047): patients either continued to receive ropeginterferon alfa-2B or received best-available treatment (hydroxyurea or another standard first-line treatment).[13]

In PROUD-PV, adverse events resulting in dose reduction occurred in 40% of the patients in the ropeginterferon alfa-2B group and 58% of patients in the hydroxyurea group. Serious treatment-related adverse events occurred in 3 of 127 patients (2%) in the ropeginterferon alfa-2B group and 5 of 127 patients (4%) in the hydroxyurea group.

The PROUD-PV study (NCT01949805) randomly assigned 257 patients with an indication for cytoreduction to receive either ropeginterferon alfa-2B or hydroxyurea. Patients could have previously received hydroxyurea for up to 3 years, but with suboptimal response or intolerance. After 1 year, patients could choose to continue study treatment in the CONTINUATION-PV trial (NCT02218047): patients either continued to receive ropeginterferon alfa-2B or received best-available treatment (hydroxyurea or another standard first-line treatment).[13]

In CONTINUATION-PV, the 5-year complete hematological response rate (with the last observation carried forward) was 72.6% (69 of 95 patients) in the ropeginterferon alfa-2B group and 52.6% (40 of 76 patients) in the best-available treatment group (rate ratio,1.43; 95% confidence interval [CI], 1.12–1.81; P = .004). The 5-year molecular response rate was 69.1% in the ropeginterferon alfa-2B group and 21.6% in the best-available treatment group (rate ratio, 3.04; 95% CI, 1.96–4.71; P < .0001). Also at 5 years, the median JAK2 V617F allele burden was better for the ropeginterferon alpha-2B group compared with the hydroxyurea group (8% vs. 44%, respectively; P < .0001).[14][Level of evidence A3]