Gupta S, Shah B, Fung CS, Chan PK, Wakefield DL, et al.
Frontiers in bioengineering and biotechnology •
Since 2015 more than 34 biosimilars have been approved by the FDA. This new era of biosimilar competition has stimulated renewed technology development focused on therapeutic protein or biologic manufacturing. One challenge in biosimilar development is the genetic differences in the host cell lines used to manufacture the biologics. For example, many biologics approved between 1994 and 2011 were expressed in murine NS0 and SP2/0 cell lines. Chinese Hamster ovary (CHO) cells, however, have since become the preferred hosts for production due to their increased productivity, ease of use, and stability. Differences between murine and hamster glycosylation have been identified in biologics produced using murine and CHO cells. In the case of monoclonal antibodies (mAbs), glycan structure can significantly affect critical antibody effector function, binding activity, stability, efficacy, and half-life. In an attempt to leverage the intrinsic advantages of the CHO expression system and match the reference biologic murine glycosylation, we engineered a CHO cell expressing an antibody that was originally produced in a murine cell line to produce murine-like glycans. Specifically, we overexpressed cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH) and N-acetyllactosaminide alpha-1,3-galactosyltransferase (GGTA) to obtain glycans with N-glycolylneuraminic acid (Neu5Gc) and galactose-α-1,3-galactose (alpha gal). The resulting CHO cells were shown to produce mAbs with murine glycans, and they were then analyzed by the spectrum of analytical methods typically used to demonstrate analytical similarity as a part of demonstrating biosimilarity. This included high-resolution mass spectrometry, biochemical, as well as cell-based assays. Through selection and optimization in fed-batch cultures, two CHO cell clones were identified with similar growth and productivity criteria to the original cell line. They maintained stable production for 65 population doubling times while matching the glycosylation profile and function of the reference product expressed in murine cells. This study demonstrates the feasibility of engineering CHO cells to express mAbs with murine glycans to facilitate the development of biosimilars that are highly similar to marketed reference products expressed in murine cells. Furthermore, this technology can potentially reduce the residual uncertainty regarding biosimilarity, resulting in a higher probability of regulatory approval and potentially reduced costs and time in development.
Bylsma LC, Dean R, Lowe K, Sangaré L, Alexander DD, et al.
Cancer medicine •
Systemic cancer therapies may induce infusion reactions (IRs) or hypersensitivities. Metastatic colorectal cancer (mCRC) patients treated with anti-EGFR therapies, including cetuximab and panitumumab, may be subject to these reactions. We conducted a meta-analysis to estimate the IR incidence in this population and identify variations in this incidence by patient or study characteristics. A systematic review was conducted to identify observational studies or clinical trials of mCRC patients treated with anti-EGFR therapies that reported occurrences of IRs, hypersensitivity, or allergy/anaphylaxis. The objective of the study was to estimate the incidence of IRs. Random effects models were used to meta-analyze the incidence of IRs overall and stratified by therapy type, study design, geographic location, RAS or KRAS mutation status, grade of reaction severity, and terminology used to describe the reaction. The pooled estimate for IR incidence was 4.9% (95% confidence interval: 3.6%-6.5%). Lower-grade reactions were more common than higher-grade reactions overall and the incidence of reactions among cetuximab patients was nearly four times that of panitumumab patients (6.1% vs 1.6%). IRs occur in approximately 5% of mCRC patients treated with anti-EGFR therapies, and the incidence varies significantly by grade of severity and therapy type. Studies evaluating these outcomes should consider investigating survival outcomes by IR status to determine its prognostic relevance.
Foley KA, Wang PF, Barber BL, Long SR, Bagalman JE, et al.
Annals of oncology : official journal of the European Society for Medical Oncology •
Systemic agents in cancer treatment were often associated with possible infusion reactions (IRs). This study estimated the incidence of IRs requiring medical intervention and assessed the clinical and economic impacts of IRs in patients with colorectal cancer (CRC) treated with cetuximab. Details on patients with CRC receiving cetuximab in 2004-2006 were extracted from a large USA administrative claims database. IRs were identified based on the occurrence of outpatient treatment, emergency room (ER) visit, and/or hospitalization for hypersensitivity and allergic reactions. Multivariate regressions were used to examine potential risk factors and quantify the economic impact of IRs. A total of 1122 CRC patients receiving cetuximab were identified. The incidence of IRs requiring medical intervention was 8.4%. Sixty-eight percent of the patients had treatment disruptions and 34% discontinued cetuximab treatment. Mean adjusted costs were $13,863 for cetuximab administrations with an IR requiring ER visit or hospitalization and $6280 for those with an IR requiring outpatient treatment, compared with $4555 for those without an IR. The incidence rate of cetuximab-related IRs requiring medical intervention in clinical practice was found to be higher than rates reported in the product label and clinical trials. The clinical and economic impacts of these IRs are substantial.
