SYNERGY

SYNERGY randomised 1,022 men with chemotherapy-naive metastatic castration-resistant prostate cancer to docetaxel and prednisone with or without custirsen, an antisense oligonucleotide against the chaperone protein clusterin. Randomisation was stratified by opioid use for cancer-related pain and by radiographic evidence of progression.

Median overall survival was 23.4 months (95 percent confidence interval 20.9 to 24.8) with custirsen and 22.0 months (19.5 to 24.0) without, hazard ratio 0.93 (0.79 to 1.10, p=0.415).

The commonest grade 3 or worse events with custirsen against control were neutropenia (grade 3 in 13 against 6 percent, grade 4 in 20 against 15 percent), febrile neutropenia (grade 3 in 10 against 6 percent) and fatigue (grade 3 in 11 against 8 percent). Serious adverse events were reported for 214 of 501 men (43 percent) on custirsen and 181 of 499 (36 percent) on control, and adverse events were attributed to 23 and 24 deaths respectively.