Background：Lacnotuzumab, as known as MCS110, is a novel, high-affinity, humanized, anti-CSF-1 monoclonal antibody that prevents CSF-1 from activating the CSF-1R. The drug is being developed by Novartis Europharm Limited. On 15 October 2014, orphan designation EU/3/14/1350 was granted by the European Commission to Novartis for recombinant human monoclonal antibody of the IgG1 kappa class against human macrophage colony-stimulating factor for the treatment of tenosynovial giant cell tumor, localized and diffuse type. They conducted a phase 1 study to assess the safety and tolerability of administering single ascending doses and repeat doses of lacnotuzumab to healthy volunteers, and to examine the pharmacokinetics PK, pharmacodynamics PD, and mechanistic properties of lacnotuzumab. Nonclinical investigations of the mechanism of action of lacnotuzumab were also performed to explain the observed adverse events AEs profile associated with CSF-1 pathway inhibition. Lacnotuzumab was generally well tolerated. The majority of AEs were low grade, no unexpected or novel AEs were observed, and there were no discontinuations for AEs. Lacnotuzumab also showed dose-dependent, on-target effects on multiple downstream biomarkers. Preclinical investigations of the CK elevation and periorbital swelling observed after lacnotuzumab administration suggest that these are reversible, nonpathological events linked to inhibition of the CSF-1 pathway. These data support further evaluation of lacnotuzumab in clinical studies.
