GSK ovarian and womb cancer drug shows promise in early trial

GSK said its ovarian cancer drug shrank or cleared tumours in more than 60 per cent of patients in an early trial as CCO Luke Miels pushes faster development.

The company said that in an early-stage trial, Mocertatug Rezetecan, known as Mo-Rez, shrank or eliminated tumours in 62 per cent of patients with ovarian cancer after chemotherapy had failed, and in 67 per cent of those with endometrial cancer.

Hesham Abdullah, GSK’s global head of cancer research and development, said: “Treatment of gynaecological cancers remains a major challenge, with a pressing need for new therapies that offer improved response rates.

“With Mo-Rez we now have compelling evidence of a promising clinical profile.”

GSK acquired the Mo-Rez treatment, an antibody-drug conjugate, from China’s Hansoh Pharma in late 2023 and has trialled it in 224 patients around the world, including the UK, over the past year.

Only a few patients needed to stop treatment because of side effects, the most common being nausea.

It is given every three weeks by intravenous infusion, meaning directly into a vein.

Combined with data from a separate intermediate trial in China, the results have given the British drugmaker the confidence to go straight to late-stage trials, with five clinical studies planned globally in the next few months, including on patients in the UK.

Speaking to journalists before the conference, Abdullah described Mo-Rez as a “key asset” in the company’s growing cancer portfolio.

It is expected to be a blockbuster drug, with peak annual sales of more than £2bn, which GSK hopes will help it achieve its 2031 sales target of £40bn.

A few years ago GSK did not have any cancer drugs on the market, but it now has four approved medicines and 13 in clinical development.

Last year, oncology generated nearly £2bn in sales, up 43 per cent from 2024, with sales of its endometrial cancer drug Jemperli rising 89 per cent.