Jakafi for Myelofibrosis Associated With Skin Cancer, Shingles Risk

Patients with myelofibrosis have a higher incidence of secondary cancers, specifically non-melanoma skin cancer, according to findings from researchers. Furthermore, there is a greater likelihood of shingles among patients who were treated with Jakafi (ruxolitinib), especially those who were exposed to the treatment for at least three years.

Real-world data on the safety profile of long-term exposure to Jakafi were presented at the 2025 European Hematology Association Congress. Researchers reported that patients who received treatment with Jakafi for at least three years were 2.3 times more likely to also receive a diagnosis of non-melanoma skin cancer than patients who were not exposed to the treatment. Additionally, patients who were treated with Jakafi for at least three years were 3.6 times more likely to receive a diagnosis of shingles than those who were not treated with Jakafi, according to the published data.

Researchers obtained data for 16,745 patients with myelofibrosis: 954 who had been treated with Jakafi continuously for at least three years, 2,547 who had been treated for a shorter period of time, and 16,745 who had had no exposure to Jakafi.

"In this large sample of patients with myelofibrosis, we found a higher incidence of non-melanoma skin cancer in patients treated with Jakafi, especially when exposed for at least three years, but not a higher incidence of other solid tumors," researchers, including Dr. Alberto Blanco Sánchez and colleagues, concluded in an abstract presentation of the data posted to the Congress' website. "We confirmed a higher rate of shingles that rose with treatment duration."

Sánchez is a researcher with the Hematology and Hemotherapy Service at The Hospital Universitario 12 de Octubre, a public hospital in Madrid, Spain. Dr. Sánchez and his fellow researchers further noted that the risk was significantly higher for pneumonia, sepsis, and urinary tract infection in the short-term exposure group, with the caveat that these could have been discontinuation-leading events and as a result, they may be overrepresented in that group.

More About Myelofibrosis and Jakafi

A type of myeloproliferative neoplasm, or MPN, myelofibrosis is a chronic blood cancer that involves the formation of excessive scar tissue in a patient's bone marrow, impairing its ability to produce normal, healthy blood cells, according to the MPN Research Foundation.

As defined by the National Cancer Institute on its website, Jakafi is a type of treatment known as a tyrosine kinase inhibitor. It is designed to block a protein known as JAK, which may help prevent abnormal blood cells or cancer cells from growing. As Dr. Sánchez and his colleagues explained, Jakafi is the first JAK inhibitor to be approved by the U.S. Food and Drug Administration (FDA) as a front-line treatment for myelofibrosis.

The researchers stated that its typically associated side effects are primarily hematologic, along with an increased risk of infections and symptoms such as fatigue and dizziness, with most of these side effects presenting in the first weeks of treatment. However, some side effects, such as shingles, could occur later and increase over time.

According to safety information posted to the official website of Jakafi, some patients have experienced certain types of non-melanoma skin cancers during treatment with the drug, and a patient's healthcare provider is advised to regularly check their skin. Furthermore, patients are advised to tell their healthcare provider if they develop any new or changing skin lesions while undergoing treatment with Jakafi.

References

1. “Safety Profile Of Long-term Exposure To Ruxolitinib In Patients With Myelofibrosis, Analysis From A Real-world Data Network,” by Dr. Alberto Blanco Sánchez, et al. 2025 European Hematology Association Congress; June 11 to 14, 2025; Milan, Italy. Abstract PF829.
2. “Myelofibrosis,” by MPN Research Foundation. https://mpnresearchfoundation.org/primary-myelofibrosis-pmf/.
3. “Jakafi,” by National Cancer Institute. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/jakafi.
4. “Important Safety Information,” by Jakafi. https://www.jakafi.com/.

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