Could This Cancer Drug Benefit Patients with Severe Asthma?

An early-phase study suggests that a targeted cancer drug, imatinib (Gleevec, Novartis), may help treat patients with severe asthma.¹ Although the small-scale study was not large enough to confirm its results, the researchers found that measures of airway inflammation were reduced in participants taking the drug.

The results, which were published in The New England Journal of Medicine, showed that the chronic myeloid leukemia drug targets specific immune cells that are known to cause lung inflammation. The study was conducted in part at Washington University School of Medicine in St. Louis and led by Brigham and Women’s Hospital and Harvard Medical School.

A team of researchers assessed 62 patients at 7 academic medical centers nationwide with poorly-controlled severe asthma symptoms. Imatinib was evaluated for its potential to impact severe asthma in a trial that randomly assigned patients to either take imatinib or a placebo as a treatment. The participants took the drug daily over a 6-month period, while the researchers assessed measures of asthma severity and airway inflammation in the beginning, at the 3-month mark, and at 6 months.

After 3 months, airway responsiveness decreased 50% in patients treated with imatinib compared to those receiving a placebo. A similar difference was observed at the 6-month mark. The researchers also noted that imatinib reduced serum tryptase, a market of mast cell activation.²

Overall, patients receiving the cancer drug performed better in assessment of airway reactivity and obstruction than those receiving a placebo. Although the improvement modestly reached statistical significance, it showed little evidence that clinical asthma symptoms improved over the course of the study.

“We are still in the early phase of this research,” Washington University co-author Mario Castro, MD, the Alan A. and Edith L. Wolff Professor of Pulmonary and Critical Care Medicine, said in a press release.³ “The data are intriguing and promising, but we will need a much larger trial, perhaps with 300-500 patients over a longer period of time, to see if Gleevec can have an impact on asthma symptoms and quality of life.”

Patients taking imatinib and a placebo experienced similar numbers of adverse events. However, patients taking imatinib were more likely to experience muscle cramps and low blood phosphate levels. One concern highlighted by the researchers noted imatinib’s effect on suppressing the immune system in patients taking the drug, which resulted in 1 patient stopping the trial due to low white blood cell counts.

Although the results are promising, the researchers concluded that larger-scale studies over longer periods of time are needed to confirm imatinib’s efficacy for treating patients with severe asthma.

References

• Cahill KN, Katz HR, Cui J, et al. KIT inhibition by imatinib in patients with severe refractory asthma. N Engl J Med. 2017. 376:1911-1920. May 18, 201;. doi: 10.1056/NEJMoa1613125
• Proof-of principle study finds imatinib improves symptoms for patients with severe asthma [news release]. Brigham and Women’s website. http://www.brighamandwomens.org/about_bwh/publicaffairs/news/pressreleases/PressRelease.aspx?sub=0&PageID=2724. Accessed May 19, 2017.
• Cancer drug may help patients with severe asthma [news release]. WUSTL’s website. https://medicine.wustl.edu/news/cancer-drug-may-help-patients-severe-asthma/. Accessed May 19, 2017.