A patient can receive phlebotomy for 30 years or however long it takes. However, the patient does have to tolerate iron deficiency, which can be problematic. Some patients who are iron deficient do not feel well; however, once someone becomes iron deficient, their symptoms are well controlled. However, getting them to that point is a challenge.
What ongoing clinical trial are you excited about?
There is a clinical trial investigating TGR-1202, which is a PI3K inhibitor. That trial is for patients whose disease is not controlled with ruxolitinib alone so it uses ruxolitinib plus TGR-1202 for control of their PV. That is going to be a unique case where you cannot control the PV well with just ruxolitinib, but it does provide a potential therapeutic option.
Unfortunately, there is not a huge number of therapeutic options for PV but, that is largely related to the fact that the ones we have are quite effective.
Are researchers looking at pacritinib in PV?
That is primarily in myelofibrosis right now. Pacritinib could have potential for patients with PV as it is a JAK inhibitor, which works well in this setting. Although, right now, both pacritinib and fedratinib are in such precarious positions with trying to get FDA approval, that they are going to wait for that before they pursue it for patients with PV.
What are the biggest unanswered questions for patients with PV that you would like to tackle in the next couple of years?
I am interested in how to treat patients who do not have a JAK2
mutation and have erythrocytosis. Currently, there is not a good answer for that. These patients have a very substantial symptom burden that is often not addressed, even if the patient has a JAK2
mutation. It is hard to say whether this is something that the PV does to the brain or if this is something that is a cytokine dysregulation feature, which you would expect to be controlled with ruxolitinib.
Addressing the needs of those patients is very important because their quality of life suffers from having that disease. Patients experience severe fatigue and chronic pain. There is also anxiety and distress associated with this disease.
Kiladjian JJ, Verstovsek S, Griesshammer M, et al. Results from the 208-week (4-year) follow-up of RESPONSE trial, a phase 3 study comparing ruxolitinib (rux) with best available therapy (BAT) for the treatment of polycythemia vera (PV). In: Proceedings from the 2017 ASH Annual Meeting; December 9-12, 2017; Atlanta, Georgia. Abstract 322.