# SYNERGY

Source: https://onco.cc/trials/synergy-custirsen/  
OnCo record `synergy-custirsen` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Blocking the survival protein clusterin did not make chemotherapy work better for advanced prostate cancer.

## Summary

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.

## Fields

- Kind: Trial
- Status: negative
- Last checked: 2026-09-25
- Also known as: SYNERGY; custirsen with first-line docetaxel
- Registry id: NCT01188187
- Phase: 3
- Setting: Metastatic castration-resistant prostate cancer with no previous chemotherapy, PSA above 5 and Karnofsky score 70 percent or higher: docetaxel 75 mg/m2 with prednisone 5 mg twice daily, with or without weekly custirsen 640 mg after three loading doses, with overall survival as the primary endpoint
- Sponsor: OncoGenex Technologies
- Enrolled: 1022
- Result: Median overall survival 23.4 against 22.0 months (hazard ratio 0.93, 95 percent confidence interval 0.79 to 1.10, p=0.415): no benefit.
- Outcomes: Overall survival (median): Docetaxel, prednisone and custirsen 23.4 months vs Docetaxel and prednisone 22 months, HR 0.93
- Replication: AFFINITY tested the same drug with cabazitaxel after docetaxel in 635 men and also found no benefit.

## Sources

- ClinicalTrials.gov NCT01188187: https://clinicaltrials.gov/study/NCT01188187
- SYNERGY (Lancet Oncology 2017): https://doi.org/10.1016/S1470-2045(17)30168-7

## Connected records

- cancers: [Metastatic castration-resistant prostate cancer](https://onco.cc/cancers/prostate-mcrpc/), [Prostate cancer](https://onco.cc/cancers/prostate/)
- technologies: [Cytotoxic chemotherapy](https://onco.cc/technologies/cytotoxic-chemotherapy/), [Oligonucleotide therapeutics](https://onco.cc/technologies/antisense-sirna/)
- drugs: [Custirsen](https://onco.cc/drugs/custirsen/), [Docetaxel](https://onco.cc/drugs/docetaxel/), [Prednisone](https://onco.cc/drugs/prednisone/)
- companies: [Achieve Life Sciences (formerly OncoGenex)](https://onco.cc/companies/achieve-life-sciences/)
- terms: [Castration-resistant prostate cancer (CRPC)](https://onco.cc/terms/castration-resistance/), [Prostate cancer programmes that failed, and what each failure taught](https://onco.cc/terms/prostate-failed-programmes/)
- trials: [AFFINITY](https://onco.cc/trials/affinity-custirsen/), [TAX 327](https://onco.cc/trials/tax-327/)

---
JSON: https://onco.cc/api/v1/entities/synergy-custirsen.json