Deciphera Pharmaceuticals has announced positive findings from the Phase III INVICTUS clinical trial that evaluated ripretinib for the treatment of fourth-line and fourth-line plus gastrointestinal stromal tumours (GIST).

Ripretinib is an investigational inhibitor of KIT and PDGFRα kinase switch control.

The randomised, double-blind, placebo-controlled, international, multi-centre trial was designed to investigate the drug’s safety, tolerability and efficacy in 129 patients who received at least three prior therapies.

According to the study’s top-line data, ripretinib met the primary endpoint with significant improvement in progression-free survival (PFS) compared to placebo.

The drug demonstrated a median PFS of 6.3 months versus one month in placebo. It also significantly minimised the risk of disease progression or death by 85%.

Ripretinib did not show statistical significance on the major secondary endpoint of objective response rate (ORR), where the ORR was 9.4% and 0% for the drug and placebo arms, respectively.

However, Deciphera’s drug demonstrated a clinically meaningful improvement in overall survival (OS).

During the trial, ripretinib was generally well tolerated and the adverse events were consistent with those observed in previous Phase I studies.

Deciphera Pharmaceuticals president and CEO Steve Hoerter said: “The data from INVICTUS reinforce our belief that ripretinib has the potential to transform the treatment of GIST, and our focus now turns to working closely with the FDA as they evaluate ripretinib for those patients with GIST who, having failed all currently approved therapies, are in desperate need of a treatment option.”

The company is planning to file a new drug application (NDA) to the FDA in the first quarter of next year to seek approval for the drug in advanced GIST.