Projects targeting the neonatal Fc receptor (FcRn) are already attracting much attention: Argenx’s efgartigimod, which only recently moved into phase III, has already attracted blockbuster sales forecasts. So Alexion’s swoop on Syntimmune today, for $400m up front, could yet be seen as a bargain; the private biotech’s anti-FcRn antibody SYNT001 is one of the few assets in the class in clinical trials. Aggressive clinical plans for the project were unveiled: even though a phase Ia/IIb trial has yet to be completed, pivotal studies in warm autoimmune haemolytic anaemia (WAIHA) and another as-yet-undisclosed indication will commence next year. In terms of the competition, executives pointed to SYNT001’s fast onset of action and what could be a lower potential for immunogenicity than other agents in development. Many of the illnesses being pursued by developers of anti-FcRn agents are chronic, so confirmation of long-term safety and tolerability remains crucial. However, the mechanism could plausibly revolutionise the treatment of a broad range of IgG-mediated autoimmune conditions, so the enthusiasm here is understandable. As owners of the only unencumbered clinical stage assets – assuming Argenx is intent on going it alone – Momenta and Affibody could well start to attract more interest.
|The FcRn pipeline|
|ARGX-113 (efgartigimod)||Anti-FcRn antibody fragment||Argenx||Plans to initiate phase III trials in second indication, ITP|
|Rozanolixizumab||Anti-FcRn MAb||UCB||Final phase II results expected at Ash in Dec 2017|
|Synt001||Anti-FcRn MAb||Syntimmune||Company bought by Alexion for $400m up front in Sep 2018, primarily for Synt001|
|M281||Anti-FcRn MAb||Momenta||Plans to intiate phase II trials in Q4 2018|
|ABY-039||Anti-FcRn antagonist (antibody mimetic)||Affibody||P1 proof of principle study started in Mar 2018|
|RVT-1401/HL161||Anti-FcRn MAb||Immunovant/Hanall||Licensed from Hanall in Dec 2017 for $30m up front in deal worth up to $503m|