GSK, the FTSE 100 pharmaceuticals group, has reported that a licensed cancer drug more than halved the risk of death in a late-stage trial in China.
The pivotal ARTEMIS-008 study showed that risvutatug rezetecan, known as Ris-Rez, cut the risk of death by 54% against topotecan, a standard treatment, in patients with relapsed small cell lung cancer.
The drug is licensed from Hansoh Pharmaceutical Group, a Chinese drugmaker.
Patients given Ris-Rez lived a median of 18.5 months, compared with 10.3 months for those on topotecan.
Topotecan is the usual option after the disease progresses following first-line platinum-based chemotherapy.
The trial met its main goal after a median follow-up of 12.2 months, with a hazard ratio of 0.46.
The results are the first from a Phase III study to show a survival benefit for a treatment aimed at B7-H3, a protein found on tumour cells, in any cancer type.
Ris-Rez belongs to a class known as antibody-drug conjugates, which pair an antibody with a cancer-killing agent to deliver it straight to the tumour.
The drug also carried a cleaner safety profile.
Severe treatment-related side effects occurred in 60.9% of patients, against 78.2% of those on topotecan.
Hesham Abdullah, GSK's senior vice president and global head of oncology research and development, said the survival improvement and the safety data gave further momentum to the company's global development of the drug.
GSK holds exclusive rights to develop and sell Ris-Rez outside mainland China, Hong Kong, Macau and Taiwan.
It is targeting lung and prostate cancers among other solid tumours.
The company's Phase III EMBOLD SCLC-301 trial, in relapsed extensive-stage small cell lung cancer, is expected to deliver pivotal data next year.
