Assessing product and process comparability culminates in the understanding of the consequence of a change as it relates to
ensuring the safety and efficacy of products. The information that feeds the understanding includes historical product/process
variability, the science of the molecules, and objective comparability acceptance criteria that provide the path forward in
the decision making. At the end of the study, the goal is to make the desired change and state with confidence that the historical
and new process/product are comparable with no adverse impact on product quality, safety, or efficacy.
The most appropriate methodology when assessing comparability is the use of an equivalence test. The steps for conducting
an equivalence test are the same when comparing means or stability slopes. Specifically, one defines the EAC using scientific
knowledge and historical process variability, determines an appropriate experimental design to minimize type 1 and type 2
errors, collects the data, and interprets the results. If the EACs are appropriately established, passing an equivalence test
provides the strongest statistical evidence of comparability.
Leslie Sidor* is director of quality engineering and Rick Burdick is principal quality engineer, both at Amgen Global Quality Engineering; Darrin Cowley is director of product quality and Brent Kendrick is scientific director, both at Amgen Analytical Sciences, firstname.lastname@example.org
1. ICH, Q5E Comparability of Biotechnological/Biological Products Subject to Change in Their Manufacturing Process (Geneva, June 2005).
2. D. Chambers et al., Pharm. Technol. 29 (9), 64–80 (2005).
3. C. Chen et al., BioPharm Int.
23 (2), 40–45 (2010).
4. M.J. Chatfield and P.J. Borman, Anal. Chem.
81 (24), 9841–9848 (2009).
5. S. Welleck, Testing Statistical Hypotheses of Equivalence (Chapman and Hall/CRC, Boca Raton, FL, 2003).