Early Research of Birabresib in Lung Cancer and Other Solid Tumors
Posted: Monday, December 17, 2018
In a phase Ib trial, Christophe Massard, MD, PhD, of the Institut Gustave Roussy, Villejuif, France, and colleagues found that the first-in-class drug birabresib (MK8628/OTX015), a bromodomain inhibitor, has dose proportional exposure, rapid absorption, and a favorable toxicity profile. In fact, clinical activity was reported for a select patient population. For future phase II testing in solid tumors, the authors a dose of 80 mg once a day with continuous dosing. These results were published in the Journal of Clinical Oncology.
In this multicenter, nonrandomized, open-label trial, 46 patients with various tumor types received birabresib. A total of 10 patients had non–small cell lung cancer; in addition, there were 26 patients with castration-resistant prostate cancer and 10 patients with nuclear protein in testis midline carcinoma. They were started at 80 mg once daily continuously (cohort A) or 100 mg for 7 consecutive days (cohort B) in 21-day cycles with parallel dose escalation. Patients received a median of three 21-day cycles.
Dose limiting toxicities occurred in 21% of evaluable patients in cohort A, and in two-thirds of patients in cohort B. No dose-limiting toxicities were observed for patients in cohort B. Of those with lung cancer, seven experienced stable disease and two had disease progression. In total, 83% of patients had treatment-related adverse events, the most common being diarrhea (37%), nausea, (37%), anorexia (30%), vomiting, (26%), and thrombocytopenia (22%).
“Future evaluations of birabresib need to consider intermittent scheduling to mitigate the potential toxicities of continuous dosing,” the authors concluded.