GSK Puts Up $100 Million for Mersana’s HER2-Targeting ADC Candidate

In its second high-profile deal this year, Mersana Therapeutics is set to receive $100 million upfront from GSK for the exclusive global license option for its preclinical antibody-drug conjugate (ADC) candidate, XMT-2056, designed to target HER2 proteins present in a variety of cancer types. If GSK chooses to exercise the licensing rights, Mersana could stand to make up to $1.36 billion in development, regulatory, and commercial milestone payments. 

Leveraging Mersana’s ADC-Focused Development Program

Mersana’s entire pipeline is dedicated to ADC development, with five products in various stages of development. GSK’s interest lies in XMT-2056, an ADC that targets an epitope of HER2 while leveraging STING signaling to activate the immune system. 

The Massachusetts-based company says XMT-2056 has demonstrated anti-tumor properties in preclinical trials as a monotherapy and has shown increased efficacy in combination with established treatments like trastuzumab, pertuzumab, and anti-PD-1 therapies. Mersana plans to launch Phase 1 studies in various HER2-expressing tumor areas like breast, gastric, and non-small cell lung cancers. In May this year, the FDA granted XMT-2056 orphan drug designation to treat gastric cancer. 

Anna Protopapas, President and Chief Executive Officer of Mersana Therapeutics, said, “We believe this agreement solidifies Mersana’s position as a partner of choice during this momentous period in the ADC space and serves as validation for our Immunosynthen platform, which takes ADCs beyond the cytotoxic realm by enabling a targeted stimulation of the innate immune system.”

GSK is already an active player in the ADC arena with its approved myeloma treatment, Blenrep. The addition of XMT-2056 would add a new development project for the company, which it hopes will pay dividends as development progresses.

Related Article: First Therapy for HER2-Low Breast Cancer Approved by FDA

ADCs Taking the Industry by Storm

Of the 12 FDA-approved ADCs on the market today, five received approval within the last five years. The huge scientific and technological advancements are spurring rapid advancement in the field, with industry leaders jumping on board to capitalize on the promising sector. 

The most recent big news in the arena came last week when AstraZeneca’s Enhertu received approval for another indication, making it the first targeted therapy for HER2-low breast cancer. 

Other big news revolves around high-figure deals with ADC-based companies like ImmunoGen’s potential $1.7 billion deal with Eli Lilly. Immunogen is also recently submitted a Biologics License Application on its own for an ADC candidate, which will receive an FDA response by November this year. 

Mersana’s most recent deal with GSK is not its first either. In February, Mersana teamed up with Janssen to develop multiple ADC candidates. That deal brought Mersana $40 million upfront with the potential for $1 billion in back-end payments. 

The ADC space is going strong, and several big companies are banking on licensing deals with smaller, more ADC-focused companies to bring the next big oncology candidate to the scene. GSK’s deal with Mersana is another step in that process, highlighting the value industry leaders see in ADC development. 

Author

Reed Slater