GSK says early trial data for its experimental targeted cancer therapy Mo-rez suggest significant anti-tumor activity in difficult-to-treat gynecological cancers, and company officials described the medicine as having blockbuster potential.
Speaking with journalists about the initial results, GSK's head of oncology research, Hesham Abdullah, identified Mo-rez as one of the group's priority assets. He told reporters that the company believes the drug could reach blockbuster status - a view he repeated on the call discussing the data scheduled for presentation at a medical conference in Puerto Rico.
The early results focused on the share of patients who achieved what the study defined as a meaningful reduction in tumor size - at least a 30% shrinkage. In patients with platinum-resistant ovarian cancer, 62% reached that threshold. In patients with endometrial cancer, 67% experienced comparable reductions in tumor size.
Analysts have not yet produced sales forecasts for Mo-rez, reflecting the preliminary nature of the trial findings. Still, GSK executives see the data as providing momentum to the firm's fast-growing oncology unit. The company’s chief executive, Luke Miels, who took on the role in January, has said the business will accelerate development of new medicines. Abdullah noted that the change in leadership and strategy is already visible in the pace and conviction behind current programmes.
Mo-rez is being evaluated in two late-stage trials targeting ovarian and endometrial cancers. GSK also plans to initiate three additional studies in the coming months, expanding the clinical programme around the therapy.
The drug is an antibody-drug conjugate - a type of therapy that attaches a potent cytotoxic agent to an antibody that targets cancer cells. Mo-rez is designed to bind to the B7H4 protein, which the company says is present on gynecological cancer cells but largely absent from healthy tissue. The broader market context for antibody-drug conjugates is noted in the data: the market for ADC treatments is projected to reach $31 billion by 2030.
GSK acquired the rights to Mo-rez through a licence agreement with China’s Hansoh Pharma in 2023. The company is advancing the medicine through clinical development while assessing its commercial prospects, though no formal sales projections have been set based on the current early-stage evidence.
As GSK continues its clinical work, the company has indicated an intent to accelerate development efforts under its current leadership. The combination of the reported tumor shrinkage percentages, ongoing late-stage trials, and plans for additional studies underpins GSK's internal view of Mo-rez as a priority oncology asset.
Summary - Early clinical data show Mo-rez produced tumor shrinkage in a majority of treated patients with platinum-resistant ovarian and endometrial cancers. GSK describes the drug as a priority asset with potential to become a blockbuster and is expanding late-stage clinical testing.