Table 1.

Drug discovery and development stage specific strategies to reduce viscosities of highly concentrated antibody solutions.^*

Strategy	Stage of drug discovery and development	Potential approach to reduce viscosity	Additional considerations
I	Early discovery stage. Several candidates (10—100) are available and platform formulations have been defined	Rank antibody candiates for viscosity at high concentration using computational and experimental techniques	Prioritize the candidates that show low viscosities at high concentrations, if all other attributes are comparable
II	Lead candidate is identified but sequence optimization for easier developability, in platform formulations, is allowed	Generate variants of the lead candidate for reduced viscosity via rational design	Test variants for biological activity and other developability attributes
III	Lead candidate is already in advanced drug development stages and/or no sequence changes are allowed	Optimize the formulation and/or use viscosity reducing excipient(s)	Formulation change at advanced stages of drug development may be time consuming and costly because the reformulated drug product may need to be tested again for stability and safety. Use of novel excipient(s) may require additional safety considerations

^*Refer to text for applications of these strategies.