OncoGenex Pharmaceuticals Announce Phase 2 Apatorsen Data from Two Clinical Trials

OncoGenex Pharmaceuticals (NASDAQ: OGXI) reported apatorsen results from two randomized Phase 2 clinical trials which were presented at the American Society of Clinical Oncology 2017 Genitourinary Cancers Symposium in Orlando, held February 16th- 18th. The clinical data demonstrated apatorsen was well-tolerated and improved patient outcomes when administered in combination with standard-of-care treatments.
As quoted in the press release:

Bladder Cancer Trial The Borealis-2™ trial evaluated apatorsen in combination with docetaxel treatment in 200 patients with metastatic bladder cancer whose disease had progressed following first-line platinum-based chemotherapy. The primary endpoint analysis met the superiority test for overall survival, performed at a one-sided 0.10 significance level using a stratified log-rank test.
Patients who received apatorsen treatment experienced a 20% reduction in risk of death, compared to patients receiving docetaxel alone (overall survival hazard ratio (HR)=0.80; 80% CI: 0.65-0.98; p=0.078).
Partial or complete responses occurred in 16.2% patients receiving apatorsen plus docetaxel compared to 10.9% patients receiving docetaxel alone with median response durations of 6.2 months versus 4.4 months, respectively.
Higher baseline serum Hsp27 levels were significantly prognostic for indicating an almost 2-fold higher risk of death (HR= 1.96; p=0.0001). In an exploratory analysis on a subset of patients (20% of total) who completed at least two treatment cycles and had either a decrease in serum Hsp27 levels from baseline or had only a 20.5% increase in serum Hsp27 levels from baseline, the reduction in risk of death with apatorsen treatment was 71% (HR= 0.29: 80% CI: 0.18-0.48; interaction p=0.0727).
Apatorsen was well tolerated in combination with docetaxel with a median treatment of 2 cycles.
The Borealis-2 trial was an investigator-sponsored trial conducted by the Hoosier Cancer Research Network at 28 sites across the United States.
Prostate Cancer Trial The Pacific™ trial evaluated the ability of apatorsen, when added to Zytiga® (abiraterone acetate), to reverse or delay treatment resistance in 72 men who were experiencing a rising PSA on Zytiga alone. The primary endpoint evaluated the proportion of patients who were progression free (clinical and radiologic) at study day 60 with apatorsen added to Zytiga, compared to continuing Zytiga alone.
In men receiving apatorsen, 33% were progression free at study day 60 compared to 17% for those men receiving Zytiga alone.
For patients with ≥5 circulating tumor cells (CTCs) at baseline, 22% vs 11% of patients had a CTC reduction to less than 5 CTCs when apatorsen was added to Zytiga vs Zytiga alone, respectively.
Apatorsen was well tolerated in combination with Zytiga with a median duration of 106 days.
The Pacific trial was an investigator-sponsored trial conducted by the Hoosier Cancer Research Network at sites in Canada and the United States.
“These data further reinforce our belief that by targeting heat shock protein 27 (Hsp27), apatorsen can improve outcomes of exisiting cancer therapies across various mechanisms of action, as demonstrated here with cytotoxic and hormonal treatments,” said Scott Cormack, President and CEO of OncoGenex. “Given the biologic rationale for combining apatorsen with checkpoint inhibitors and other immune modulators, we are engaging in partnering discussions to further explore these development opportunities.”

Click here for the full press release.