Forlong Biotechnology announced on 10 July that China's Centre for Drug Evaluation (CDE) granted investigational new drug (IND) approval for its IL-15/IL-15Rα fusion protein FL115 in combination with Innovent Biologics' PD-1 inhibitor sintilimab for advanced solid tumours. The Ib/II trial marks the fourth clinical study for Forlong's IL-15 agonist, which demonstrated 57% tumour shrinkage in a Phase I lung squamous carcinoma patient.

FL115 leverages synergistic NK and T-cell activation with PD-1 blockade, showing potential to overcome checkpoint inhibitor resistance. Pre-clinical data revealed enhanced antitumour activity when combined with sintilimab. The candidate is undergoing three Phase I trials in China and the US, positioning Forlong as a leader in cytokine-based immuno-oncology therapies.