According to WHO annual analyzes, in 2021 there were barely 27 new antibiotics in clinical development against priority pathogens, down from 31 products in 2017, while in the preclinical stage the number of products has remained relatively constant over the last three years.
More broadly the report described that, of the 77 antibacterial agents in development, 45 are traditional direct-acting small molecules and 32 are non-traditional agents.
Since antibiotics now have a limited lifespan before drug resistance emerges, non-traditional approaches offer new opportunities to tackle infections from different angles as they can be used complementarily and synergistically or as alternatives to established therapies.
Barriers to development of new products include the lengthy pathway to approval, high cost and low success rates. It currently takes approximately 10–15 years to progress an antibiotic candidate from the preclinical to the clinical stages.
For antibiotics in existing classes, on average, only one of every 15 drugs in preclinical development will reach patients. For new classes of antibiotics, only one in 30 candidates will reach patients.