The patients received MLN8237 in 21-day cycles: seven days of twice-daily 50mg treatment, followed by a 14-day break. Three patients had a partial response to the treatment, and 5 had stable disease that was sustained for at least four 21-week cycles, the researchers report.
"The most important finding from this study was the fact that MLN8237 demonstrates single-agent activity in ovarian cancer with encouraging durable disease control in some patients," Dr Matulonis said.
Several patients have remained on the study drug for over 12 months, she noted. "I personally have a patient on this current study who has been on MLN8237 for now more than 12 months. She is doing remarkably well."
The fact that multiple patients had stable disease or response suggests that future development of MLN8237 in combination with other active agents may be a promising avenue to investigate, the researchers said.
"These durable responses are encouraging since all of the patients enrolled on this study have failed platinum. Because of the other durable responses reported in other MLN8237 studies, this all helps support the prediction that this is a new mechanism to fight cancer, and the MLN8237 drug does not appear to share mechanisms for resistance to other available drugs."
The researchers noted that the drug had various toxicities. The most common serious toxicities included neutropenia, stomatitis, leucopenia, thrombocytopenia and fatigue, which were generally reversible during the 14-day break in treatment. Five patients discontinued due to adverse events.
The fact that the drug has shown some efficacy in treating drug-resistant ovarian cancer "is worth exploring further," noted Professor Stan Kaye, Professor of Medical Oncology at the Royal Marsden Hospital.
|Contact: Vanessa Pavinato|
European Society for Medical Oncology