In general terms of monoclonal antibody (and other proteins) manufacturing, Drug Substance (essentially pure Leronlimab) can sit frozen at -80C for several years. A 15000L process run yields only a very small fraction of pure drug substance. Common for antibodies is about 4-8g/L of cell culture.

The formulation and final fill finish of this DS takes a relatively short time to complete. The final formulation known as Drug Product is what has the 2 year expiry.