More than 2,400 men tested in largest worldwide studies to date
DiagnoCure, Inc. (TSX: CUR), a life sciences company commercializing high-value cancer diagnostic tests and delivering laboratory services, announced that the clinical utility of the PROGENSA(R) PCA3 test, developed and commercialized by its partner Gen-Probe (NASDAQ: GPRO), was confirmed in two large worldwide studies, conducted in a subset of patients in GlaxoSmithKline's REDUCE trial of dutasteride. The results demonstrate that PCA3 can help determine whether men suspected of having prostate cancer should undergo a repeat biopsy and can predict the risk of having an aggressive cancer. The studies were presented last week at the American Society of Clinical Oncology's Genitourinary Cancers Symposium (ASCO GU) in San Francisco.
"This four-year multicenter worldwide study is the largest to date performed on DiagnoCure's PCA3 marker. It shows that the test can be useful in managing patients suspected of having prostate cancer. For doctors and patients struggling with the dilemma of the traditional PSA test that has a well-known low specificity, the PCA3 test, with a specificity of up to 80% (depending on the cut-off), can offer a more reliable answer. These results indicate that the PCA3 test can help reduce unnecessary prostate biopsies and help identify patients that have a more aggressive cancer, representing a step forward in personalized patient care," said Dr Yves Fradet, co-founder and President of DiagnoCure.
In the studies presented at the ASCO GU meeting, PCA3 was used to test urine samples from men enrolled in the REDUCE trial of GlaxoSmithKline's drug dutasteride. PCA3 testing was done on urine samples from 1,140 men in the placebo arm of the REDUCE trial, and from 1,308 men treated with dutasteride. All men underwent prostate biopsies two and four years after enrollment in the study.
The first PCA3 study presented at the meeting originated from the placebo arm of the REDUCE trial. This study, which was highlighted in ASCO's official press program, showed that PCA3 scores were significantly correlated with a positive prostate biopsy result, and that men who had higher PCA3 scores were more likely to have prostate cancer. Specifically, cancer was diagnosed in only 6% of men with very low PCA3 scores, but in 57% of men with very high PCA3 scores.
PCA3 scores also correlated with cancer aggressiveness (as defined by the Gleason Score): median PCA3 scores were higher in men with high-grade cancers than in those with low-grade cancers. Finally, the PCA3 test also predicted the likelihood of a positive prostate biopsy performed two years after the test.
The second PCA3 study originated from the patients treated with dutasteride in the REDUCE trial. This study demonstrated that PCA3 also can be used to predict prostate biopsy outcomes in men taking dutasteride. It confirmed earlier research that showed PCA3 outperforms serum PSA testing for prostate cancer detection, and improves diagnostic accuracy when combined with serum PSA testing and other clinical information.