Brilacidin is not limited by cytotoxicity which is what Selectivity Index revolves around.
The question we are answering with the current phase 2 trial is whether Brilacidin is effective against COVID at dosages which have proven relatively safe in the ABSSSI trial.
We can't raise the dosage much due to systemic effects (really really high BP) which tanked the Polymedix trial.
Selectivity index doesnt mean much to us at this point. Its all about whether B works near the current dose or not. The SI would have one believe we can crank up the dose if needed....but we cant.