New CMO brings more than 20 years of experience in complex organizational settings

 SOUTH RIDING, VA. – August 31, 2023Slone Partners, a nationwide executive search firm for life sciences, biotechnology, and healthcare companies, today announced the successful placement of Christophe Arbet-Engels, MD, PhD, as Chief Medical Officer (CMO) at X4 Pharmaceuticals, Inc., a biopharmaceutical company developing novel small molecule therapeutics to benefit patients with diseases of the immune system.

Arbet-Engels previously served as CMO at several life science companies, including Neurogastrx, Millendo Therapeutics, and Poxel Pharmaceuticals, where he provided research and development leadership, advancing multiple candidates from pre-clinical through to late-stage clinical trials. Prior to these roles, he held a variety of senior medical and clinical positions at Biogen, Boehringer-Ingelheim Pharmaceuticals, Hoffmann-La Roche, Merck Research Laboratories, Aventis Pharmaceuticals, and Ligand Pharmaceuticals, where he led clinical development and registration, launch and lifecycle management efforts for several new medicines.

“Dr. Arbet-Engels is a highly respected and experienced global pharmaceutical executive with keen business acumen honed over more than 20 years serving in complex organizational settings,” said Leslie Loveless, Slone Partners CEO. “We are very pleased to have been able to place him at X4 where we believe his extraordinary drive, passion, and vision – and his proven track record of success – will make a wonderful addition to the company’s leadership team.”

“It was truly a pleasure collaborating with Slone Partners on the placement of Christophe as our new Chief Medical Officer,” said Paula Ragan, Ph.D., President and Chief Executive Officer of X4 Pharmaceuticals, “We very much value our relationship with the Slone team and consider them a valuable ongoing resource to X4 given their deep understanding of and high quality connections within the life science industry.”


Slone Partners delivers the leaders who build amazing and diverse life sciences and healthcare organizations – People Are Our Science®. Founded in 2000, Slone Partners specializes in delivering world-class C-suite leadership, executive, and upper management talent to the most promising and established biotech, diagnostics, research tools, healthcare, precision medicine, medical device, and laboratory services companies. With national and global clients, Slone Partners uniquely and precisely provides an array of executive search and advisory services, including diversity, equity, and inclusion strategy, to innovative life sciences and healthcare companies. To learn more about Slone Partners’ value proposition and processes, visit or call 888.784.3422.