Galactose Oxidase Enables Modular Assembly of Conjugates from Native Antibodies with High Drug-to-Antibody Ratios**

The potential of antibody conjugates with high drug loading in anticancer therapy has recently been highlighted by the approval of Trastuzumab deruxtecan and Sacituzumab govitecan. These biopharmaceutical approaches have spurred interest in bioconjugation strategies with high and defined degrees of drug‐to‐antibody ratio (DAR), in particular on native antibodies. Here, a glycoengineering methodology was developed to generate antibody drug conjugates with DAR of up to eight, by combining highly selective enzymatic galactosylation and oxidation with biorthogonal tandem Knoevenagel–Michael addition chemistry. This four‐step approach offers a selective route to conjugates from native antibodies with high drug loading, and thus illustrates how biocatalysis can be used for the generation of biopharmaceuticals using mild reaction conditions

Galactose Oxidase Enables Modular Assembly of Conjugates from Native Antibodies with High Drug-to-Antibody Ratios

The potential of antibody conjugates with high drug loading in anticancer therapy has recently been highlighted by the approval of Trastuzumab deruxtecan and Sacituzumab govitecan. These biopharmaceutical approaches have spurred interest in bioconjugation strategies with high and defined degrees antibody-to-drug (DAR) ratios, in particular on native antibodies. Here we report a glycoengineering methodology to generate antibody drug conjugates with DAR of up to eight, by combining highly selective enzymatic galactosylation and oxidation with biorthogonal tandem Knoevenagel-Michael addition chemistry. This three step approach offers a selective route to conjugates from native antibodies with high drug loading, and thus illustrates how biocatalysis can be used for the generation of biopharmaceuticals using mild reaction conditions

Development and application of a highly α2,6-selective pseudosialidase

In this manuscript we address an important gap in our current carbohydrate active enzyme toolbox, by developing a highly a2,6-selective (over a2,3-selective) de facto sialidase that is necessary both for glycan analysis and glycoconjugate remodeling. Both glycosidic linkages are commonly found in animal biology and each has been shown to have distinct biological function. Our approach is novel in that it harnesses the high selectivity of known glycosyltransferases ‘in reverse’ for effective hydrolysis, converting transferases to hydrolases by reaction engineering. More specifically, we demonstrate that the a2,6-specific pseudosialidase activity of Photobacterium sp. JT-ISH-224 a2,6-sialyltransferase can be used effectively for highly a2,6 selective hydrolysis on a broad range of analytes: small synthetic probes, isolated complex glycans and complex mixtures of glycoproteins. </p

Development and application of a highly α2,6-selective pseudosialidase

<p>In this manuscript we address an important gap in our current carbohydrate active enzyme toolbox, by developing a highly a2,6-selective (over a2,3-selective) de facto sialidase that is necessary both for glycan analysis and glycoconjugate remodeling. Both glycosidic linkages are commonly found in animal biology and each has been shown to have distinct biological function.</p> <p>Our approach is novel in that it harnesses the high selectivity of known glycosyltransferases ‘in reverse’ for effective hydrolysis, converting transferases to hydrolases by reaction engineering. </p> <p>More specifically, we demonstrate that the a2,6-specific pseudosialidase activity of <i>Photobacterium </i>sp. JT-ISH-224 a2,6-sialyltransferase can be used effectively for highly a2,6 selective hydrolysis on a broad range of analytes: small synthetic probes, isolated complex glycans and complex mixtures of glycoproteins. </p

Mammographic surveillance in women younger than 50 years who have a family history of breast cancer: tumour characteristics and projected effect on mortality in the prospective, single-arm, FH01 study.

BACKGROUND: Evidence supports a reduction in mortality from breast cancer with mammographic screening in the general population of women aged 40-49 years, but the effect of family history is not clear. We aimed to establish whether screening affects the disease stage and projected mortality of women younger than 50 years who have a clinically significant family history of breast cancer. METHODS: In the single-arm FH01 study, women at intermediate familial risk who were younger than 50 years were enrolled from 76 centres in the UK, and received yearly mammography. Women with BRCA mutations were not explicitly excluded, but would be rare in this group. To compare the FH01 cohort with women not receiving screening, two external comparison groups were used: the control group of the UK Age Trial (106,971 women aged 40-42 years at recruitment, from the general population [ie, average risk], followed up for 10 years), and a Dutch study of women with a family history of breast cancer (cancer cases aged 25-77 years, diagnosed 1980-2004). Study endpoints were size, node status, and histological grade of invasive tumours, and estimated mortality calculated from the Nottingham prognostic index (NPI) score, and adjusted for differences in underlying risk between the FH01 cohort and the control group of the UK Age Trial. This study is registered with the National Research Register, number N0484114809. FINDINGS: 6710 women were enrolled between Jan 16, 2003, and Feb 28, 2007, and received yearly mammography for a mean of 4 years (SD 2) up until Nov 30, 2009; surveillance and reporting of cancers is still underway. 136 women were diagnosed with breast cancer: 105 (77%) at screening, 28 (21%) symptomatically in the interval between screening events, and three (2%) symptomatically after failing to attend their latest mammogram. Invasive tumours in the FH01 study were significantly smaller (p=0·0094), less likely to be node positive (p=0·0083), and of more favourable grade (p=0·0072) than were those in the control group of the UK Age Trial, and were significantly less likely to be node positive than were tumours in the Dutch study (p=0·012). Mean NPI score was significantly lower in the FH01 cohort than in the control group of the UK Age Trial (p=0·00079) or the Dutch study (p<0·0001). After adjustment for underlying risk, predicted 10-year mortality was significantly lower in the FH01 cohort (1·10%) than in the control group of the UK Age Trial (1·38%), with relative risk of 0·80 (95% CI 0·66-0·96; p=0·022). INTERPRETATION: Yearly mammography in women with a medium familial risk of breast cancer is likely to be effective in prevention of deaths from breast cancer