Obtaining relevant and accurate information on pharmacokinetics (PK) and exposure for biotherapeutics is one of the key fundamental elements in research and development (R&D) process. Typical R&D process if often described in several steps starting with discovery phase continuing through several development phases. In the early discovery phase, multiple candidates or even various modalities of the drug in development are evaluated, including comparison of the PK properties. As an example, half-life for a monoclonal antibody (mAb) or a Fcfusion compound may be compared to a typical mAb based drug or the impact of a specific mutation designed to improve compound PK properties are assessed. Appropriate description of the PK properties for a biotherapeutic requires access to solidly developed bioanalytical methods with high specificity, selectivity and sensitivity allowing for evaluation of drug concentrations. Any protein based biotherapeutics is expected to carry various degree of immunogenicity risk therefore requiring an in study assessment of immunogenicity response. Well designed and high quality bioanalytical strategy therefore enables an effective understanding of the exposure-response relationship including assessment of toxicity and efficacy.