Though there are few therapeutic options for patients with myelofibrosis, Jakafi (ruxolitinib) represents an important look towards the future, according to Maureen E. Thyne, a physician assistant in the Outpatient Leukemia Service at Weill Cornell Medical College.
Jakafi is an oral Janus-associated kinase 1 (JAK1) and JAK2 inhibitor medication approved for the treatment of patients with intermediate or high-risk myelofibrosis, including primary myelofibrosis, post-polycythemia vera myelofibrosis and post-essential thrombocythemia myelofibrosis.
To gain insight into the treatment of the disease and the clinical utility of Jakafi, CURE interviewed Thyne at the 2016 Oncology Nursing Society Congress.
What were you tasked with presenting here at the meeting?
I'm here presenting on Jakafi (ruxolitinib) and its use in myelofibrosis — specifically, its use in intermediate and high-risk disease. This is a rare disease. Myelofibrosis affects fewer than 20,000 people in the country, so it's not particularly common, and there hadn't been any effective, FDA-approved therapies until Jakafi came along. It's exciting and it's done a great job in this patient population.
Prior to Jakafi coming onto the scene, what did treatment for patients with myelofibrosis look like?
We were able to use some combinations of transfusions, supportive care and chemotherapeutics that were non-specific to myelofibrosis. The only potential for cure was through bone marrow transplant, and that remains to be the case. With Jakafi, we have a therapy that's been designed specifically to help symptom burden and specific side effects from the disease. These patients typically experience enlarged spleens, so Jakafi not only shrinks them but also improves symptom status.
How are patients doing on the drug?
It's been several years since the approval, but the results have been impressive. Overall survival has been improved, and we didn't expect to see the level improvement that we have so quickly. We'll have five-year data later this year, so I'm anxious to see those results.
What are the next steps in myelofibrosis?
It's tough with rare diseases across the board, and myelofibrosis certainly resides in that group. There are limited therapies directed at the diseases — Jakafi is the only one approved now, but there are several others in clinical trials for patients who have been exposed to Jakafi and have not responded or have progressed through their responses. It's an exciting time in the myeloproliferative neoplasm world.
What about the side effects of Jakafi? What should patients and health care professionals expect?
Like all drugs, Jakafi comes along with its own set of side effects. The most common reported symptoms from patients were bruising, dizziness and headache — that corresponded with a temporary drop in some of their blood counts. Patients did get transfused if their counts dropped low enough that they would need it. We know that the drug drops blood counts, so in the first couple of weeks of treatment, we watch counts pretty carefully.
There are some other liver abnormalities and cholesterol increases that can happen, too.
What are the challenges with developing agents to treat myelofibrosis?
With rare diseases, it's tricky to get solid attention towards getting drugs that are effective and mass-marketed. Again, this is not unique to myelofibrosis.
Now that we've identified a pathway behind the disease, with JAK-STAT activation, I think we're on the road towards even more options for patients.
What else are you excited about in myelofibrosis and oncology in general?
It's amazing how oncology has progressed in the past few years, with respect to our identification and action upon certain mutations. Molecular genetics has become a really hot topic in many fields of oncology; it has not only enabled us to make better diagnoses, but even to classify them better.
Ultimately, the goal is to find targetable mutations and develop therapies for them.
That’s not exactly the case for myelofibrosis right now. We've identified a pathway that is the problem, and Jakafi and drugs that are in trials are targeting that pathway. In other malignancies, it's the mutations that have been a really big deal.