Comparability has become a routine exercise throughout the life cycle of biotechnological products. According to ICH Q5E, a comparability exercise should provide analytical evidence that a product has highly similar quality attributes before and after manufacturing process changes, with no adverse impact on safety or efficacy, including immunogenicity (1). Any doubt about data from such studies could translate into unforeseen pharmacological or nonclinical studies — or worse, clinical studies. Selection of analytical methods and acceptance criteria that will be applied…