Lausanne (Switzerland) and Santiago de Compostela (Spain) – September 30, 2025 – Privately held Swiss biopharmaceutical company Debiopharm has signed a licensing agreement with SunRock Biopharma to develop SRB21, a bispecific antibody against HER3 and HER2. SunRock, a Galician company supported by the Xunta de Galicia through Xesgalicia, specializes in developing antibodies against highly invasive tumors with urgent clinical needs.
With this agreement, Debiopharm will exercise its license option on SRB21 to combine it with its proprietary MultiLINK™ Linker technology and create a new antibody-drug conjugate (ADC), which will be marketed under the name Debio 2512.
Toward the next generation of ADCs
Debiopharm will apply its “Trifecta” strategy—strategic target selection, innovative linkers, and intelligent choice of cytotoxic payloads—to design a precision ADC. Bispecific ADCs have the potential to increase treatment efficacy and specificity by targeting two antigens simultaneously, reduce adverse effects, and overcome resistance mechanisms.
“Bispecific ADCs are one of the most promising approaches in oncology,” said Bertrand Ducrey, CEO of Debiopharm. “This license allows us to apply our MultiLINK™ technology to a dual design that could pave the way for revolutionary therapies for HER-driven cancers.”
HER2-driven tumors are associated with more aggressive growth, early relapses, and greater resistance to treatment. Although current therapies have led to significant advances, many patients eventually develop resistance and metastasis, limiting the durability of the response and long-term survival benefits. By simultaneously targeting HER2 and HER3, SRB21 could overcome this resistance and prolong clinical response.
“The licensing of SRB21 is a strategic milestone for SunRock Biopharma and a validation of our bispecific antibody platform,” said Laureano Simón, CEO of SunRock. “With Debiopharm, we aim to accelerate the development of next-generation ADCs that offer new opportunities for patients with HER2-resistant tumors.”
“Patients with HER2-positive cancers require therapies capable of anticipating and overcoming tumor resistance,” added Frédéric Levy, CSO of Debiopharm. “Our ‘Trifecta’ approach, combined with a bispecific HER3/HER2 antibody, represents a very promising advance in treating difficult-to-treat tumors.”
Debiopharm’s ADC Experience
We are developing fit-for-purpose antibody-drug conjugates using a customized “Trifecta” approach: strategic target selection, innovative patented MultiLINK™ linker technology, and intelligent choice of therapeutic loads.
The Swiss company boasts a robust portfolio of anti-drug conjugates (ADCs), including Debio 1562M (anti-CD37, in clinical trials for acute myeloid leukemia and myelodysplastic syndromes) and Debio 0532 (anti-HER3 for solid tumors), in addition to programs in development against undisclosed targets. Its in-house expertise spans conjugation and PK/PD optimization to toxicology, clinical development, and supply chain management.
About SunRock Biopharma
SunRock Biopharma develops first-class, bispecific therapeutic antibodies against innovative targets such as CCR9 and recognized targets such as HER3. Its shareholders include the EAF Spain – Isabel la Católica Fund (EIF) and XesGalicia, the investment arm of the Xunta de Galicia (Galician Regional Government).
About Debiopharm
Debiopharm develops innovative therapies in oncology and infectious diseases. It identifies high-potential compounds, tests their safety and efficacy in clinical settings, and collaborates with global pharmaceutical companies to maximize patient access to these therapies.
More info: www.debiopharm.com
Follow us on X: @DebiopharmNews
LinkedIn: www.linkedin.com/company/debiopharminternational/
Press Contact:
Dawn Bonine – Head of Communications
dawn.bonine@debiopharm.com
Tel: +41 (0)21 321 01 11
