2002;62:3106C12. combination arm) were evaluable for response, with 66.7% overall response rate (PR) in combination arm, and 33.3% of disease control (SD) in single agent arm. At the time of study termination, 55.6% had progressed. Summary This study suggests Withaferin A that egression of tumor cells to the blood stream can represent a novel restorative strategy for MM. However, because of significant hematological toxicity, this study had to be discontinued. Further studies are needed to validate the feasibility of this approach in medical practice. and improved the tumor reduction induced by bortezomib . A phase I study of plerixafor and bortezomib in RRMM individuals  shown transient de-adhesion of MM cells in most of the individuals as soon as 2 hours post-plerixafor and during 4 to 24 hours. The combination of plerixafor and bortezomib was very active and generally well tolerated with this study. F50067 (F50067 hz515H7-1), a humanized monoclonal IgG1 anti-CXCR4 antibody that specifically focuses on CXCR4, has proven preclinical encouraging anti-tumor activity in MM. F50067 is definitely expected to exert its effect through a dual part, disrupting the connection of MM cells with the BM microenvironment and triggering both complement-dependent cytotoxicity (CDC) and antibody-dependent Withaferin A cellular cytotoxicity (ADCC). F50067 may also sensitize MM cells to the effects of lenalidomide and low-dose dexamethasone. A series of and preclinical investigations assessed that F50067 binds the human being CXCR4, efficiently competes for SDF-1 binding, and inhibits CXCR4 receptor-mediated Withaferin A G-protein activation. F50067 antibody was shown to induce CDC and ADCC on a panel of malignancy cells = 9) = 14) = 1= 4= 3= 2= 1= 3MM models by enhancing the level of sensitivity of tumor cells to chemotherapy or additional targeted therapies . Pleriflaxor, a CXCR4 inhibitor, was utilized for chemosensitization in relapsed/refractory AML with motivating results . A phase I study of plerixafor and bortezomib was then carried out in RRMM individuals, with a good effectiveness and a favorable Withaferin A security profile . We have consequently wanted to conduct a phase 1 study to assess F50067, a humanized anti-CXCR4 antibody, for security and effectiveness only and in combination with lenalidomide and dexamethasone in RRMM individuals. F50067 was of particular interest as it was expected to exert a dual effectiveness mechanism. First, obstructing the CXCR4/SDF-1 connection would lead to egress of CXCR4-expressing tumor cells out of the tumor market. In addition, F50067 was designed as an IgG1 monoclonal antibody, with Fc-mediated effector functions that would result in both complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC)  against CXCR4 expressing tumor cells. We statement herein an overall response rate (ORR, PR) of 66.7.% in combination arm and a medical benefit rate (CBR, MR) of 33.3% in monotherapy, which can be considered of interest in end stage RRMM. This study indeed included an seniors populace having a median age of 71 years, and greatly pre-treated with 6.6 median prior lines of therapy. These Withaferin A results can, to a certain extent, validate the proof of concept that a disruption of the CXCR4/SDF-1 axis could be of interest in RRMM. The early signs of drug biological effect were evidenced from the activation of NK cells whatsoever dose levels. This pharmacodynamic effect can be attributed to F50067 as the antibody was demonstrated preclinical to have effector functions enabled . This suggests that actually if concentrations are not sustained due to rather low dose levels, the explored dose levels may be adequate to drive to a restorative effect in individuals. The observed results may warrant further drug and concept evaluation, providing the hematological security profile could be workable. Related ADCC inducing effect has also been demonstrated as being important for the anti-tumor activity with elotuzumab, restorative antibody against CS-1 in multiple myeloma individuals [21, 22]. This restorative approach has also been validated by others, with an ORR of 26% (including 13% of very good partial response (VGPR) or better) and a CBR of 32.6% reported in the phase I/II study combining pleriflaxor AKAP12 and bortezomib for RRMM individuals . More recently, another study combining a proteasome inhibitor with an inhibitor of the CXCR4/SDF-1 axis has been published . With this phase IIa study, olaptesed pegol,.