Unmet Needs Loom for Later-Line Options in MPNs

Srdan Verstovsek, MD, PhD, a professor of Medicine and a hematologic oncologist at the University of Texas MD Anderson Cancer Center, discusses the need for new drugs after patients with myelofibrosis are treated with JAK inhibitors.

According to Verstovsek, myelofibrosis is the deadliest myeloproliferative neoplasm, with an average survival of 5 to 7 years. Bone marrow transplant is a possibility, however, less than 10% of patients undergo the procedure. Currently, there are 2 JAK inhibitors on the market, ruxolitinib (Jakafi) and fedratinib (Inrebic), to help control symptoms and prolong survival.

After JAK inhibitors, there are no therapies approved. Additionally, no therapy exists for the treatment of anemia in this patient population. Twenty percent of patients will also go on to develop acute myeloid leukemia.

0:08 | Myelofibrosis is the deadliest of the myeloproliferative neoplasms. The average survival is 5 to 7 years, and we do not have medications that would be eliminating disease and curing the patients. That's only possible through bone marrow transplant, but less than 10% of the patients go to transplant. So, there is a need for therapies that would be controlling the signs and symptoms of the disease, at least, for a very, very long period of time to extend the life of the patients. Now we have approved therapies, in terms of two drugs that are called JAK inhibitors on the market. These are ruxolitinib and fedratinib, which are good for a duration of maybe 1 to 3 years in myelofibrosis patients to control their symptoms and control their enlarged spleen. Beyond that we don't have any other therapies. So, what therapies can we do or provide our patients after JAK inhibitors? Not much we can do. What about the third hallmark of myelofibrosis, anemia? If we have JAK inhibitors to control the symptoms and spleen, what about the anemia, which can worsen even on the therapy? As a side effect of these therapies? We don't have any therapy. Twenty percent of the patient's progress to acute myeloid leukemia. JAK inhibitors do not have effect on that risk at all. So, areas of unmet needs are number 1, a second line therapy after JAK inhibitors. After JAK inhibitors, life is usually short, terrible, very bad bone marrow function. Number 2 would be anemia. That can occur patients in frontline setting, second-line setting, in any setting because there is nothing, we can do about it. And the patients that are progressive to acute myeloid leukemia, and not forget a smaller group of people that have low platelets. This is another problem, because current JAK inhibitors do nothing for these patients. They're not even supposed to be given to patients with platelet droplets because they can worsen platelet numbers.