The gist: People with metastatic melanoma who are being treated with the drug ipilimumab (Yervoy) may live several months longer if they also take another drug called granulocyte-macrophage colony-stimulating factor (GM-CSF). In a recent clinical trial, researchers compared patients who took just ipilimumab with patients who took both ipilimumab and GM-CSF. Patients who took both lived several months longer. However, GM-CSF didn’t increase the amount of time that passed before cancer returned.
“The addition of sargramostim, a systemic granulocyte-macrophage colony-stimulating factor (GM-CSF), to the anti-CTLA-4 ipilimumab resulted in a significant improvement in overall survival in patients with metastatic melanoma when compared with treatment with ipilimumab alone, according to phase II study results published recently in JAMA: Dermatology. However, no difference in progression-free survival was found between the two study groups.
“ ‘The lack of correlation between overall survival and progression-free survival in this study presents challenges to clinical management and drug development because conventional radiographic criteria have not proven reliable for determining patient benefit,’ wrote researchers led by F. Stephen Hodi, MD, of the Dana-Farber Cancer Institute. ‘This introduces important considerations for the evaluation of treatment efficacy with particular immune therapies such as ipilimumab.’
“Previous research has shown therapeutic synergy between CTLA-4 blockade and GM-CSF secreting tumor cell vaccines. In addition, the combination of systemic GM-CSF with CTLA-4 blockade in patients with hormone-refractory prostate cancer resulted in clinical responses in more than half of patients with PSA declines.”