Data reveal is promising for GSK's lung cancer drug ris-rez

GSK has reported the first results from its international trial of B7-H3-targeted antibody-drug conjugate (ADC) risvutatug rezetecan (ris-rez) in small cell lung cancer (SCLC), building on prior results in a Chinese patient population.

The data from the phase 1b EMBOLD PanTumour-101 in patients with extensive-stage SCLC revealed a 61% overall response rate (ORR) with ris-rez at a dose of 8 mg/kg, compared to 32% with a lower 6 mg/kg dose.

Based on the results, GSK selected the 8 mg/kg dose for its ongoing phase 3 EMBOLD SCLC-301 trial of the drug, which is due to read out next year.

The data – which will be presented in a poster at the upcoming ESMO cancer congress in Madrid, Spain, later this month – have emerged just a few weeks after solid data from the phase 3 ARTEMIS-008 study run by ris-rez's originator, Hansoh Pharma, in China.

GSK licensed ris-rez in a $1.7 billion deal signed in 2023, one of two ADCs it has sourced from the Chinese biopharma company alongside B7-H4-directed mocertatug rezetecan (mo-rez), which showed efficacy in platinum-resistant ovarian cancer (PROC) and recurrent or advanced endometrial cancer in a phase 1 trial reported earlier this year.

"Today's first global data for ris-rez build on the statistically significant overall survival benefit recently reported in Hansoh's pivotal Chinese trial," said Hesham Abdullah, GSK's global head of oncology R&D.

"As the data for ris-rez continues to grow, we remain focused on accelerating development in extensive-stage small cell lung cancer, where patients often relapse quickly and urgently need more treatment options."

In ARTEMIS-008, the ADC achieved a statistically significant 54% improvement in overall survival compared to topotecan chemotherapy when used as a second-line therapy for SCLC, with patients living for a median of 18.5 months and 10.3 months, respectively. It was the first phase 3 trial to show an OS benefit for a B7-H3 ADC in any tumour type.

The lead investigator in EMBOLD PanTumour-101, Hye Ryun Kim of Yonsei Cancer Centre in South Korea, said that extensive-stage SCLC is one of the most aggressive cancers, with five-year survival rates "typically in the single digits."

He added: "Patients whose disease relapses often have limited options, and current therapies can be difficult to tolerate. The response rates and manageable safety profile observed with ris-rez are encouraging and support its ongoing development in this setting."