Biopharmaceutical company Aridis Pharmaceuticals Inc (Nasdaq:ARDS) on Tuesday announced an agreement with the US Food and Drug Administration (FDA) to simplify its AR-501 Phase 2 trial design for the treatment of chronic lung infections associated with cystic fibrosis (CF) in collaboration with the CF Foundation.

The company said AR-501 is an inhaled formulation of gallium citrate with broad-spectrum anti-infective activity being developed to treat chronic lung infections in cystic fibrosis patients.

Upon achieving positive Phase 1 safety data in healthy adults exposed to a single ascending dose (SAD) or a multiple ascending dose (MAD) regimen, the company has proposed to streamline AR-501's Phase 2a clinical trial in CF patients in only the MAD regimen.

Additionally, the FDA has accepted the company's proposal to expand the originally planned Phase 2a protocol design into a Phase 2a/2b study, which will enable seamless and efficient advancement from Phase 2a into Phase 2b using the same clinical study protocol. The data from the Phase 2a will inform the dose selection and sample size expansion to achieve statistical significance in efficacy in Phase 2b.