Risk-Based Control Strategies of Recombinant Monoclonal Antibody Charge Variants

Abstract

Since the first approval of the anti-CD3 recombinant monoclonal antibody (mAb), muromonab-CD3, a mouse antibody for the prevention of transplant rejection, by the US Food and Drug Administration (FDA) in 1986, mAb therapeutics have become increasingly important to medical care. A wealth of information about mAbs regarding their structure, stability, post-translation modifications, and the relationship between modification and function has been reported. Yet, substantial resources are still required throughout development and commercialization to have appropriate control strategies to maintain consistent product quality, safety, and efficacy. A typical feature of mAbs is charge heterogeneity, which stems from a variety of modifications, including modifications that are common to many mAbs or unique to a specific molecule or process. Charge heterogeneity is highly sensitive to process changes and thus a good indicator of a robust process. It is a high-risk quality attribute that could potentially fail the specification and comparability required for batch disposition. Failure to meet product specifications or comparability can substantially affect clinical development timelines. To mitigate these risks, the general rule is to maintain a comparable charge profile when process changes are inevitably introduced during development and even after commercialization. Otherwise, new peaks or varied levels of acidic and basic species must be justified based on scientific knowledge and clinical experience for a specific molecule. Here, we summarize the current understanding of mAb charge variants and outline risk-based control strategies to support process development and ultimately commercialization.

In-Depth Characterization of mAb Charge Variants by On-Line Multidimensional Liquid Chromatography-Mass Spectrometry

“…As shown in Figure , the TIC chromatograms of HC were consistent among all charge variants; PTMs on the HC, including glycosylation (G0F), C-terminal Lys truncation (−K, −128.2 Da), and cyclization of N-terminal Gln to pyroglutamate (Pyro Q, −17.0 Da), were identified by interpreting the MS spectra of and HC1 and HC2 peak (Figure S1 in the Supporting Information). These PTMs, are common ones and have been reported with little impact on the safety and efficacy of antibodies. , No significant difference was observed among the variants.…”

“…These PTMs, are common ones and have been reported with little impact on the safety and efficacy of antibodies. 28,29 No significant difference was observed among the variants. The LC1 peak area was found to be increased in B5-B8 variants (Figure 3A).…”

Induction of heat shock protein expression in SP2/0 transgenic cells and its effect on the production of monoclonal antibodies

“…Several modifications, including deamidation, sialylation, glycation, oxidation, cysteine-related modifications, and unformed disulfide bonds, were identified in the acidic and basic forms of the mAbs. Charge variants play a critical role in efficacy (complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity), safety (immunogenicity), and stability, which make them essential quality considerations [ 48 ]. It should be noted that medium composition is another significant factor that contributes to the formation of charge variants [ 49 ].…”

Charge heterogeneity of therapeutic monoclonal antibodies by different cIEF systems: views on the current situation

“…Due to their protein nature, and depending on the manufacturing process, mAbs can undergo various post-translational modifications (PTMs), degradation, and conformational alterations with potentially critical effects on the product efficacy and safety. 5 …”