Kelun-Biotech’s Investigational New Drug (IND) application for SKB105 (CR-003), an integrin beta-6 (ITGB6)-targeted antibody-drug conjugate (ADC), has been approved by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China for the treatment of advanced solid tumours. 

In December 2025, Kelun-Biotech and Crescent Biopharma entered a strategic collaboration for SKB105/CR-003 and SKB118 (a PD-1 x VEGF bispecific antibody, also known as CR-001).  

Under the collaboration, Kelun-Biotech granted Crescent exclusive rights to research, develop, manufacture and commercialise SKB105/CR-003 in the United States, Europe and all other markets outside of Greater China. In addition, Crescent granted Kelun-Biotech exclusive rights to research, develop, manufacture and commercialise SKB118/CR-001 in Greater China. 

SKB105 is a differentiated ADC targeting ITGB6 with a topoisomerase I inhibitor payload. ITGB6 is overexpressed in many solid tumours, but shows minimal to no expression in most normal tissues, thereby potentially reducing the risk of systemic toxicity and off-target effects.  

SKB105 incorporates proprietary Kthiol irreversible conjugation technology, linking an anti-ITGB6 fully human Immunoglobulin G1 (IgG1) monoclonal antibody (mAb) to a clinically validated cleavable linker. This design aims to enhance stability and tumour-specific payload delivery while reducing adverse effects. In preclinical models, SKB105 demonstrated a favourable efficacy, safety, and pharmacokinetic (PK) profile. 

SKB118/CR-001 is a tetravalent bispecific antibody being developed for the treatment of solid tumours that combines two complementary, validated mechanisms in oncology via a blockade of PD-1 and VEGF. 

The IND application for SKB118/CR-001 has been cleared by the US Food and Drug Administration (FDA) with a global Phase I/II clinical trial for the treatment of advanced solid tumours is set to commenceshortly.  

Kelun-Biotech has revealed plans to submit an IND application for SKB118/CR-001 to the CDE of the NMPA of China in the near future.

Diana Turner, Deputy Editor, DDW