STOCKHOLM—Follow-up data suggest that ropeginterferon alfa-2b (ropeg) provides an advantage over hydroxyurea (HU) for patients with polycythemia vera (PV), regardless of their age.
Two-year results from an extension study have shown that, compared to HU, ropeg produces higher rates of complete hematologic response (CHR) and molecular response (MR) in PV patients, including patients age 60 and older.
Additionally, rates of adverse events (AEs) and serious AEs were similar between the ropeg and HU arms.
“In all, I think these data suggest that ropeginterferon alfa-2b provides a valuable, efficacious, and safe new treatment option for PV patients of all ages, including those older than 60 years,” said Jean-Jacques Kiladjian, MD, PhD, of Hôpital Saint-Louis, Université Paris Diderot in Paris, France.
Dr Kiladjian presented these results at the 23rd Congress of the European Hematology Association (EHA) as abstract S132.
The research was sponsored by AOP Orphan Pharmaceuticals AG.
Dr Kiladjian presented data from CONTINUATION-PV, an extension trial of PROUD-PV. Results from PROUD-PV were presented at the 2016 ASH Annual Meeting.
PROUD-PV enrolled 254 patients who were treatment-naive or pretreated with HU. They were randomized to receive ropeg (n=127) or HU (n=127).
CONTINUATION-PV included 95 of the patients on ropeg and 76 of the patients on HU. Dr Kiladjian noted that baseline characteristics were similar between these groups.
|<60 years (n=49)||≥60 years (n=46)||<60 years (n=39)||≥60 years (n=37)|
|Median age (range)||51 (30-59)||64 (60-85)||50 (32-59)||66 (61-79)|
|Median duration of PV (range)||1.9 months (0-145.5)||1.7 months (0.1-102.4)||1.6 months (0-91.6)||1.7 months (0-65.6)|
|HU pretreatment||17 (34.7%)||14 (30.4%)||12 (30.8%)||13 (35.1%)|
|Mean duration of HU treatment||11.3 months||14.8 months||16.0 months||11.2 months|
|Mean JAK2V617F allele burden||38.4%||47.4%||38.1%||48.1%|
|Splenomegaly present||2 (4.1%)||5 (10.9%)||4 (10.3%)||4 (10.8%)|
|Disease-related symptoms present||5 (10.2%)||10 (21.7%)||4 (10.3%)||13 (35.1%)|
At 24 months, the rate of CHR was 70.5% (67/95) in the ropeg arm and 49.3% (33/67) in the HU arm (RR=1.42, P<0.05).
In patients younger than 60, the rate of CHR was 77.6% in the ropeg arm and 55.9% in the HU arm. In patients age 60 and older, rates of CHR were 63% and 42.4%, respectively.
Dr Kiladjian noted that CHR rates increased over time in ropeg recipients. In PROUD-PV, CHR rates were similar between the ropeg and HU arms at 12 months. However, at 24 months, the CHR rates were higher in ropeg recipients.
Ropeg recipients were also more likely than HU recipients to maintain their CHR from the first occurrence to 24 months.
In patients younger than 60, 49% of the ropeg arm and 17.9% of the HU arm maintained a CHR (P<0.001). In patients age 60 and older, rates of CHR maintenance were 37% and 18.9%, respectively.
MR and JAK2V617F allele burden
Rates of MR at 24 months were 68.1% (64/94) in the ropeg arm and 34.7% (26/75) in the HU arm (RR=1.85, P<0.01).
In patients younger than 60, the rate of MR was 77.1% in the ropeg arm and 33.3% in the HU arm (P<0.001). In patients age 60 and older, MR rates were 58.7% and 36.1%, respectively.
For patients younger than 60, the reduction in JAK2V617F allele burden at 12 months was 29.9% in the ropeg arm and 42.3% in the HU arm. At 24 months, the reductions were 54.8% and 4.5%, respectively (P<0.001).
For patients 60 and older, the reduction in JAK2V617F allele burden at 12 months was 25.2% in the ropeg arm and 37.5% in the HU arm. At 24 months, the reductions were 35.1% and 18.4%, respectively.
“I think an important point here is the safety because we assume that [ropeg] is not well tolerated in elderly patients,” Dr Kiladjian said. “So what are the results in this prospective, controlled trial? There was a comparable number of adverse events and serious adverse events in the treatment arms, irrespective of age.”
Dr Kiladjian also pointed out that the number of adverse drug reactions (ADRs) was comparable between the treatment arms for younger patients, and there was a trend toward a lower number of ADRs in the ropeg arm for the patients age 60 and older.
|Safety results at a mean of 2.7 years of treatment (up to 3.6 years)|
|<60 (n=49)||≥60 (n=46)||<60 (n=39)||≥60 (n=37)|
|Patients with any AE||44 (89.8%)||43 (93.5%)||36 (92.3%)||34 (91.1%)|
|Serious AE||3 (6.1%)||10 (21.7%)||4 (10.3%)||9 (24.3%)|
|ADR||38 (77.6%)||29 (63%)||29 (74.4%)||33 (89.2%)|
|Serious ADR||0||0||0||4 (10.8%)|
|Grade 3+ AE||10 (20.4%)||16 (34.8%)||10 (25.6%)||14 (37.8%)|
|Recovered from AE||43 (87.8%)||40 (87%)||35 (89.7%)||34 (91.9%)|
The 4 serious ADRs in the HU patients age 60 and older were acute leukemia, anemia, leukopenia, and granulocytopenia.