BioNTech’s Breakthrough in Breast Cancer Treatment
BioNTech’s HER2-directed antibody-drug conjugate has outperformed Roche’s Kadcyla in a phase 3 trial for breast cancer, setting up its partner Duality Biologics to pursue regulatory approval in China.
The candidate, trastuzumab pamirtecan (BNT323/DB-1303), employs the same HER2 antibody used in Kadcyla and in AstraZeneca and Daiichi Sankyo’s Enhertu, both of which have already been given the FDA green light. However, BioNTech and DualityBio are seeking to carve out market share by combining the well-known targeting antibody with a novel linker system and a distinct cytotoxic payload.
Phase 3 Trial Details and Outcomes
DualityBio tested its antibody-drug conjugate against Kadcyla in a phase 3 study conducted in China. The study enrolled 228 patients, who were randomized to receive either the experimental treatment or the approved comparator. All participants had previously undergone chemotherapy and treatment with trastuzumab – marketed by Roche as Herceptin – which also serves as the targeting antibody in ADCs.
An interim analysis showed the trial achieved its primary endpoint of progression-free survival. While BioNTech and DualityBio have not yet released specific data from the study, the outcome was promising enough for DualityBio to signal its intention to engage regulators in China about a potential approval filing. Under its partnership with BioNTech, DualityBio holds commercialization rights in the country.
Market Context and Future Prospects
Beating Kadcyla, which gained FDA approval in 2013, is considered a minimum requirement for contenders in the HER2 ADC field. AstraZeneca and Daiichi Sankyo’s Enhertu raised the bar in 2022, showing a 22-month progression-free survival benefit over Kadcyla in a global trial that involved a patient group similar to that of DualityBio’s study in China.
Results from DualityBio’s trial, along with upcoming data from global studies in HER2-low breast cancer and endometrial cancer, will help determine how BNT323 stacks up against Enhertu. Moreover, pairing the drug with BNT327 (BioNTech’s PD-L1xVEGF-A bispecific) could enhance its value for the German company even if it does not manage to displace Enhertu as the market leader.
Executive Commentary
Özlem Türeci, M.D., BioNTech’s CMO and co-founder, described the development as a major step in the productive collaboration with DualityBio. She noted that trastuzumab pamirtecan appeared to be an antibody-drug conjugate with significant promise, making it a key component of BioNTech’s global cancer strategy, including in combination approaches.
She further emphasized that it was the company’s first late-stage oncology program to achieve its main goal in a pivotal phase III study, underscoring BioNTech’s dedication to advancing innovative cancer therapies with unique characteristics for patients.
Other Developments
In other positive news for BioNTech, the firm has entered into a strategic alliance with Ryvu Therapeutics, a Poland-based biotech engaged in developing new cancer therapies, to improve access for local patients. As part of the collaboration, BioNTech will receive support from Ryvu in launching clinical trial sites and enrolling patients in Poland for multiple experimental immunotherapies from its oncology portfolio.
