Antibody-drug conjugates (ADCs) utilizing cysteine-directed linker chemistry have cytotoxic drugs covalently bound to native heavy-heavy and heavy-light interchain disulfide bonds. The manufacture of these ADCs involves a reduction step followed by a conjugation step. When tris(2-carboxyethyl)phosphine (TCEP) is used as the reductant, the reaction stoichiometry predicts that for each molecule of TCEP added, one interchain disulfide should be reduced, generating two free thiols for drug linkage. In practice, the amount of TCEP required to achieve the desired drug-to-antibody ratio often exceeds the predicted, and is variable for different lots of monoclonal antibody starting material. We have identified the cause of this variability to be inconsistent levels of interchain trisulfide bonds in the monoclonal antibody. We propose that TCEP reacts with each trisulfide bond to form a thiophosphine and a disulfide bond, yielding no net antibody free thiols for conjugation. Antibodies with higher levels of trisulfide bonds require a greater TCEP:antibody molar ratio to achieve the targeted drug-to-antibody ratio.

This study using streptokinase preflush in the NHBD was found to improve the condition of the kidneys retrieved. The improvement in the quality of the donor kidneys was not associated with an increased morbidity in the recipient.

Obese patients with GERD had meaningful improvement in patient-reported outcomes with the AGB system. In addition, other obesity-related comorbidities and measures of quality of life improved.

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Machine perfusion and assessment of NHBD kidneys has been successfully introduced to the Newcastle NHBD programme. This approach, using renal transplants from largely category II donors produced a success rate of 88.4% which was significantly better than the phase II period (45.5%) of the program (p=0.023, Fisher 2 tail test).