Ensuring Product Quality, Consistency and Patient Supply over Time for a Large-Volume Biologic: Experience with Remicade.

Biologics are produced from living organisms in complex, multi-stage manufacturing processes and contain inherent variability, which must be understood and controlled during manufacturing to avoid unexpected changes in key quality attributes that may contribute to clinically meaningful differences. The process must also meet large commercial demand, while simultaneously being able to accommodate change without sacrificing product consistency. The four key components of successful biologics manufacturing are (1) a stable, well-defined proprietary cell line; (2) a good manufacturing practice (GMP)-compliant supply chain with a process control strategy defining acceptable levels of variability for target product/process attributes and capable of managing complex material flows; (3) a tightly controlled procedure for implementation of proposed process changes that ensures product consistency; and (4) built-in redundancy and flexibility providing the ability to adapt rapidly to unexpected developments.

Synthesis and evaluation of 99mTc/99Tc-MAG3-biotin conjugates for antibody pretargeting strategies.

Four 99mTc-MAG3-biotin conjugates were synthesized to determine their potential use in antibody pretargeting strategies for radioimmunoscintigraphy (RIS). To use these 99mTc-MAG3-biotin conjugates as model compounds for 186Re-MAG3-biotin conjugates for radioimmunotherapy (RIT), nanomolar amounts of 99Tc were added as carrier to 99mTc. The biotin derivatives used for the preparation of the conjugates-biocytin, biotin hydrazide, biotinyl-piperazine, and biotinyl-diaminosuccinic acid-differed at the site that is regarded to be susceptible to hydrolysis by biotinidase present in human plasma.

Perspectives of combined radioimmunotherapy and anti-EGFR antibody therapy for the treatment of residual head and neck cancer.

Rhenium-186 based radioimmunotherapy (RIT) may have potential for the treatment of minimal residual disease in patients with squamous cell carcinoma of head and neck (HNSCC). In an effort to enhance the efficacy of RIT, we evaluated the combination of RIT and anti-epidermal growth factor receptor (EGFR) therapy in nude mice bearing established HNSCC s.c.

[186Re]-labeled mouse and chimeric monoclonal antibody 323/A3: a comparison of the efficacy in experimental human ovarian cancer.

We have investigated whether [186Re]-labeled chimeric monoclonal antibody 323/A3 (MAb c-323/A3) is as effective as [186Re]-labeled mouse 323/A3 (m-323/A3) in the growth inhibition of human ovarian cancer xenografts OVCAR-3 and FMa. [186Re] was conjugated to MAbs with the use of the chelate S-benzoylmercaptoacetyltriglycine (S-benzoyl-MAG3). The maximum number of metal-MAG3 groups that could be conjugated to one MAb molecule accepting a minimal initial increase of the blood clearance (15%) was 8.

High dose rhenium-186-labeling of monoclonal antibodies for clinical application: pitfalls and solutions.

Background: Rhenium-186 (186Re) has ideal properties for adjuvant radioimmunotherapy (RIT). However, the lack of suitable methods for high dose 186Re labeling of monoclonal antibodies (MAbs) has hampered the use of 186Re in clinical RIT. After development of a chemically identical multistep procedure for the production of 186Re-MAG3-MAb and 99mTc/99Tc-MAG3-MAb conjugates for use as a matched pair, the authors now report on further progress to make this labeling method broadly applicable for high dose 186Re labeling.