Targeting CD157 in AML using a novel, Fc-engineered antibody construct.

Antibody-based immunotherapy represents a promising strategy to eliminate chemorefractory leukemic cells in acute myeloid leukemia (AML). In this study, we evaluated a novel Fc-engineered antibody against CD157 (MEN1112) for its suitability as immunotherapy in AML. CD157 was expressed in 97% of primary AML patient samples. A significant, albeit lower expression level of CD157 was observed within the compartment of leukemia-initiating cells, which are supposed to be the major source of relapse. In healthy donor bone marrow, CD157 was expressed on CD34+ cells. In ex vivo assays, MEN1112 triggered natural killer (NK) cell-mediated cytotoxicity against AML cell lines and primary AML cells. Compared to its parental analogue, the Fc-engineered antibody exhibited higher antibody dependent cellular cytotoxicity responses. Using NK cells from AML patients, we observed heterogeneous MEN1112-mediated cytotoxicity against AML cells, most likely due to well-documented defects in AML-NK cells and corresponding inter-patient variations in NK cell function. Cytotoxicity could not be correlated to the time after completion of chemotherapy. In summary, we could demonstrate that CD157 is strongly expressed in AML. MEN1112 is a promising antibody construct that showed high cytotoxicity against AML cells and warrants further clinical testing. Due to variability in NK-cell function of AML patients, the time of application during the course of the disease as well as combinatorial strategies might influence treatment results.

Stereoselective alkylation of an Evans auxiliary derivative within a pressure-driven micro reactor.

A simple technique for the diastereoselective alkylation of a metal stabilised enolate is demonstrated within a pressure-driven micro reactor whereby enhanced diastereoselectivities were obtained compared to batch.

On-chip separation of peptides prepared within a micro reactor.

We have demonstrated that peptides may be electrophoretically separated from unreacted reagents within an integrated micro reactor.

The regioselective preparation of 1,3-diketones within a micro reactor.

We demonstrate a simple method for the regioselective preparation of 1,3-diketones within a micro reactor from silyl enol ethers where the products are free from both competing O-acylation and diacylation products.

Investigation of racemisation in peptide synthesis within a micro reactor.

We demonstrate that peptides derived from alpha-amino acids may be prepared in a micro reactor. The peptides were prepared in 20 min with quantitative conversion, compared to batch reactions which require prolonged reaction times. We illustrate that by using dilute reagent concentrations and short reaction times, less racemisation is observed in micro reactions than in bulk reactions.

1,4-addition of enolates to alpha,beta-unsaturated ketones within a micro reactor.

We demonstrate the formation of a series of diketone enolates and their subsequent reaction with alpha,beta-unsaturated carbonyl compounds in order to prepare a variety of Michael adducts. In all cases, the conversions observed within a micro reactor were greater than those obtained in batch.