ASCO 2024: MSD’s ADC shows efficacy in lung and breast tumours
Merck & Co (MSD) has announced positive data for its antibody-drug conjugate (ADC) therapy, sacituzumab tirumotecan from two studies that recruited patients with lung and breast cancer.
The company released first-time data from the open-label Phase II trial (NCT05351788) in patients with advanced non-small cell lung cancer (NSCLC) along with additional data from the Phase III study (NCT05347134) with the ADC in patients with advanced or metastatic triple-negative breast cancer. The results will be presented at the upcoming American Society of Clinical Oncology (ASCO) Annual Meeting taking place in Chicago from 31 May to 4 June.
Sacituzumab tirumotecan is a trophoblast cell-surface antigen 2 (TROP2)-targeting antibody linked to a belotecan-derivative topoisomerase I inhibitor payload. It has the same antibody as the Gilead Sciences’ breast cancer ADC therapy Trodelvy (sacituzumab govitecan), but has a different payload and linker. MSD licenced the ADC therapy along with six other ADC candidates from China-based Sichuan Kelun-Biotech (Kelun) in 2022.
The Phase II trial evaluated sacituzumab tirumotecan in combination with Kelun’s programmed cell death-ligand 1 (PD-L1) targeting monoclonal antibody, KL-A167, in treatment naïve NSCLC patients. The Phase III study compared sacituzumab tirumotecan to chemotherapy in 263 patients with locally recurrent or metastatic triple-negative breast cancer. The study met the primary endpoint of PFS by demonstrating a 69% reduction in risk of progression or death, based on an interim analysis with a data cutoff of 21 June 2023.
Based on the blinded independent central reviews (BICRs), the therapy has a median PFS of 5.7 months, compared to a median PFS of 2.3 months with chemotherapy. Sacituzumab tirumotecan had an ORR of 43.8% compared to a 12.8% ORR with chemotherapy.
Both Phase II and III studies were funded by Kelun. MSD is evaluating sacituzumab tirumotecan in combination with the company’s PD1 therapy Keytruda (pembrolizumab) as a first-line treatment in patients with metastatic NSCLC in a Phase III trial (NCT06170788). The trial is expected to enrol approximately 614 participants and will conclude in 2028.
Multiple companies are expected to present data for their ADC therapies at ASCO. ADCs have been an area of interest in recent months, with MSD announcing investments to boost its ADC portfolio. In October 2023, the company partnered with Daiichi Sankyo to develop and commercialise three of the latter’s DXd ADC candidates, potentially spending up to $22bn on the partnership.
May 27, 2024
