Oral C5 Inhibitor
Ra Pharma® is actively pursuing the identification of orally-available inhibitors of C5 that bind to and inhibit targets in similar ways as the Company’s peptides, providing an additional option for the treatment of PNH, gMG and LN. For example, Ra Pharma’s lead C5 inhibitor binds to a previously unrecognized site for inhibiting cleavage and activation of C5. With a long-term aim of developing a traditional small molecule inhibitor of C5 that can be delivered in pill form, Ra Pharma has developed an assay for high throughput screening of small molecule libraries for compounds that bind to the site defined by zilucoplan (RA101495 SC) and related peptides.
This screening campaign has led to the identification of small molecules that bind to C5 at this site, inhibit cleavage, and inhibit red blood cell lysis in an in vitro assay. Small molecules and peptides that bind to other sites on C5 have yielded information on new mechanisms for C5 inhibition that are expected to contribute to a pipeline of highly differentiated, orally-available products.