First FDA Approved Interferon Improves Outcomes in Polycythemia Vera

Srdan Verstovsek, MD, PhD, discusses why the first ever FDA approved interferon drug ropeginterferon alfa-2b-njft (Besremi) is important for adult patients with polycythemia vera (PV).

Results from a single arm trial (NCT01193699) over the course of 7 years showed that 61% of 51 patients on ropeginterferon alfa-2b-njft for an average of 5 years had a complete hematological response. This meant that patients had a red blood cell volume of less than 45% without a recent phlebotomy, normal white cell and platelet counts, a normal spleen size, and no blood clots. Verstovsek discusses how these encouraging results also mean the drug is safer for patients than other treatments and is encouraging for long term treatment.

Moreover, Verstovsek, professor of medicine and hematologist-oncologist at the University of Texas MD Anderson Cancer, highlights the molecular response patients had to ther therapy and how this is encouraging in a way other interferon therapy have not been before.

Transcript:

0:07 | This is not the first interferon ever used, but it was the first approved. I would say 5% to 10% of patients in the community setting are usually exposed to interferon, usually younger ones, because the issue is tolerance. This one is given under the skin every 2 weeks and appears to be tolerated well, which means that you can give it for much longer. Usually in clinical studies with prior versions of interferon is only about 3 to 5 years on average duration and look, if people live 15 to 20 years on average you need the long-term therapy. That's why hydroxyurea chemotherapy by mouth is typical choice. 9 out of 10 patients would be given hydroxyurea, but now with this interferon tolerance is improved, your abilities improved, and response is excellent.

0:53 | So, there is a potential for more and I highlighted in my presentations, the molecular response. The molecular response is where you are decreasing the JAK2 allele burden, which is the percent of cells in the sample of the patients that has mutations. This goes down over time steadily, as by 5 years about 14% of patients have undetectable JAK2 mutation. Well, people say what does this mean? I can't tell you yet, but the response prospects are that if we continue like this, and you can apparently with this drug, then more and more patients will have a molecular response and you may have a potential for disease modification. This means fewer patients having not just a blood clot risk, but also less of a transformation to myelofibrosis or AML, which are long term complications not too many people talk about. This is quite a development; it's the first jak interferon approved for PV, it's safer and appears to be able to be delivered for much longer, maintaining that response and having potential for that biological modification down the road if we continue to see patients for long term care.