Spero Therapeutics, Inc.

Steven James Stanway

Antoinette Wilson

Stephen Frederick Moss

Pamela Brown

Michael Dawson

Mona Simonovic

Steven Boakes

Esther Duperchy

The present invention provides a compound of formula (I), and its use in methods of treatment, including the treatment of bacterial infections. Methods for the preparation of the compound of formula (I) are also provided. The compound of formula (I) has the structure shown below, where —Rand —Rare each together with the carbonyl group and nitrogen alpha to the carbon to which it is attached an amino acid residue, except that R6 together with the carbonyl group and nitrogen alpha to the carbon to which it is attached is not a phenylalanine, leucine or valine residue and/or —Rtogether with the carbonyl group and nitrogen alpha to the carbon to which it is attached is not a leucine, iso-leucine, phenylalanine, threonine, valine or nor-valine residue, and -T, -A, -A, -Aand —Rare as discussed in the application:

Polymyxin compounds and uses thereof

Growing community of inventors

Ongar, United Kingdom

Steven James Stanway