The agreement also expands a previously existing collaboration between the two enterprises to allow Takeda access to Mersana’s antibody-drug conjugate (ADC) platform Fleximer, while granting Mersana an option at the end of Phase 1 to jointly develop and commercialize one of these programs in the U.S. Takeda and Mersana also will co-develop new payloads for use with ADCs.
XMT-1522 is an investigational HER2-targeting therapy based on the Fleximer immunoconjugate technology. It carries nearly 15 proprietary auristatin payload molecules. The Fleximer-based ADC therapy targets HER2-expressing tumors, including gastric, breast cancer, and non-small cell lung cancers (NSCLC).
Preclinical data shows that patients with HER2 low-expressing cancers reported significant anti-cancer activity, and patients with HER2 high-expressing cancers who had not responded well to currently available therapies also reported the same anti-tumor activity.
“We believe XMT-1522 has the potential to make a dramatic difference for HER2 low-expressing patients who currently have limited treatment options, and are confident that our Fleximer-based technology can address significant patient needs not currently met by other ADC platform technologies,” Mersana President and CEO Anna Protopapas said in a press release.
“Takeda’s knowledge of oncology and commitment to ADCs as a key therapeutic approach make the company the best partner for us to progress our transformative platform and advance XMT-1522 into the clinic,” Protopapas said.
XMT-1522 will be co-developed by Takeda and Mersana, with Mersana leading the Phase 1 clinical trial. Mersana will have full rights for commercial use in America and Canada, while Takeda will own rights elsewhere. The partnership also provides Takeda with access to other targets included in Mesana’s Fleximer-based ADC platform. The companies also will work together to leverage Takeda’s proprietary small molecule libraries so that they can pinpoint and develop novel payloads that the two parties can use in new ADC therapies.
“This is our third collaboration with Mersana in less than two years. We see great potential for Mersana’s Fleximer technology, combined with our oncology expertise and resources, to extend the benefits of targeted therapy with ADCs to underserved cancer patient populations,” said Takeda’s CMO and CSO, Andrew Plump, M.D., Ph.D.
“We, along with the global oncology community, have made great strides in our fight against cancer, and we know that achieving our aspiration to cure cancer relies on great partnerships and innovation. We look forward to progressing these collaborations and together, advancing the science of cancer care,” Plump said.