AstraZeneca PLC and Merck & Co. Inc. said combining their drug Lynparza with a standard of care hormone therapy worked better than using the hormone therapy alone to delay prostate cancer from progressing.
The results are from a phase 2 trial, called Study 08, which enrolled 142 patients with previously treated, castration-resistant prostate cancer that has spread to other parts of the body.
The trial met its main goal of median radiologic progression-free survival, or rPFS — the length of time patients live after treatment without seeing the cancer worsening. Patients who received Lynparza and the hormone therapy, called abiraterone, had a median rPFS of 13.8 months, compared to 8.2 months in the monotherapy group.
For patients whose cancer expressed a type of genetic mutation called the homologous recombination repair mutation, the median rPFS was 17.8 months in the combination therapy arm, compared to 6.5 months in the monotherapy arm.
Serious adverse events and discontinuation of the treatment were more frequent among patients treated with Lynparza and abiraterone. The most common serious adverse events were anemia, pneumonia and myocardial infarction.
AstraZeneca is co-developing and marketing Lynparza, also known as olaparib, in a partnership with Merck &Co. The drug is already approved to treat certain patients with breast cancer and ovarian cancer.
Abiraterone, which Johnson & Johnson markets as Zytiga, is the current standard of care for prostate cancer.
Prostate cancer is the second most common cancer in men, with an estimated 1.6 million new cases diagnosed worldwide in 2015, and is associated with a significant mortality rate. Metastatic castration-resistant prostate cancer, or mCRPC, occurs when prostate cancer grows and spreads to other parts of the body despite using hormone therapy to block the action of male sex hormones.
The 2018 American Society of Clinical Oncology meeting is expected to bring together more than 32,000 professionals from all over the world, with more than 2,500 study abstracts to be presented on site and an additional 3,350 abstracts to be published online.
