Deregulation of the HER family of receptor tyrosine kinases plays an important role in the development and progression of human cancer. Targeting the HER family member EGFR for instance provides clinical benefit in patients with colorectal, non-small cell lung cancer or squamous cell carcinoma of head and neck. Similarly, targeting the member HER2 has significantly improved overall survival in patients with breast cancer or gastric carcinoma. Accumulating evidence indicates, however, a high degree of HER family cross-talk and compensatory signaling leading to resistance upon therapeutic intervention with one of the receptors.

Sym013 or pan-HER is the most advanced product in Symphogen's pre-clinical oncology pipeline. Pan-HER is a mixture of six humanized full length monoclonal antibodies targeting EGFR, HER2 and HER3, all validated targets for cancer treatment, that effectively induces simultaneous down-modulation of all three targets and prevents compensatory receptor up-regulation. In Symphogen's research, simultaneous targeting of three receptors has been shown to provide broader efficacy than targeting of a single receptor or any combination of two receptors in the HER family.