PEGylation Does Not Significantly Change the Initial Intravenous or Subcutaneous Pharmacokinetics or Lymphatic Exposure of Trastuzumab in Rats but Increases Plasma Clearance after Subcutaneous Administration

Abstract

The lymphatic system plays a major role in the metastatic dissemination of cancer and has an integral role in immunity. PEGylation enhances drainage and lymphatic uptake following subcutaneous (sc) administration of proteins and protein-like polymers, but the impact of PEGylation of very large proteins (such as antibodies) on subcutaneous and lymphatic pharmacokinetics is unknown. This study therefore aimed to evaluate the impact of PEGylation on the sc absorption and lymphatic disposition of the anti-HER2 antibody trastuzumab in rats. PEG-trastuzumab was generated via the conjugation of a single 40 kDa PEG-NHS ester to trastuzumab. PEG-trastuzumab showed a 5-fold reduction in HER2 binding affinity, however the in vitro growth inhibitory effects were preserved as a result of changes in cellular trafficking when compared to native trastuzumab. The lymphatic pharmacokinetics of PEG-trastuzumab was evaluated in thoracic lymph duct cannulated rats after iv and sc administration and compared to the pharmacokinetics of native trastuzumab. The iv pharmacokinetics and lymphatic exposure of PEG-trastuzumab was similar when compared to trastuzumab. After sc administration, initial plasma pharmacokinetics and lymphatic exposure were also similar between PEG-trastuzumab and trastuzumab, but the absolute bioavailability of PEG-trastuzumab was 100% when compared to 86.1% bioavailability for trastuzumab. In contrast to trastuzumab, PEG-trastuzumab showed accelerated plasma clearance beginning approximately 7 days after sc, but not iv, administration, presumably as a result of the generation of anti-PEG IgM. This work suggests that PEGylation does not significantly alter the lymphatic disposition of very large proteins, and further suggests that it is unlikely to benefit therapy with monoclonal antibodies.

Frequent transmission of the Mycobacterium tuberculosis Beijing lineage and positive selection for the EsxW Beijing variant in Vietnam

“…Protein was expressed, purified and refolded following the method of Mahmood and colleagues81. Solution microscale thermophoresis (MST) binding studies were performed to measure the binding affinity of EsxV for both the wildtype and mutant EsxW, using standard protocols on a Monolith NT.115 (Nanotemper Technologies)82–84. The EsxW was chosen to be labelled due to the presence of a lysine in EsxV at the heterodimer binding interface.…”

Challenges and Opportunities in the Delivery of Cancer Therapeutics: Update on Recent Progress

“…The derivatization of Abs or proteins as PEG conjugates was also described for their sc. administration to increase their hydrodynamic diameter, reduce the kidney excretion and enhance their lymphatic uptake [133], such as in the case of Somavert R , a PEG-HGH antagonist marketed by Pfizer for the treatment of acromegaly [134]. The SC administration can also take advantage of intrinsic properties of the drug substance.…”

Homogentisate 1,2-dioxygenase (HGD) gene variants, their analysis and genotype–phenotype correlations in the largest cohort of patients with AKU

“…not analyzed published protocols [30]. SEC-MALS analysis was performed to determine the experimental molecular weight of the recombinant HGD complexes as previously described [31][32][33][34]. Details can be found in Supplementary Methods.…”