MicroCal offers four instruments: VP-ITC, VP-DSC, VP-Capillary DSC (ten times the throughput of the VP-DSC), and the AutoITC, which runs 100 samples per week unattended.
How Much Testing?
The ability to characterize biomolecules has exploded in the last 10–15 years, which creates a tempting situation where developers of biotherapeutics can overtest. “This conservative thinking can sometimes cause people to hold a molecule back,” observes Dr. Lively of PPD. Developers need to be aware of their stage of development, he says, and test appropriately and in line with what regulators expect. “Investigators need to match the scope of characterization and the level of validation to the phase of development that they are in and they need to discuss this scope with the agency.”
How much testing is enough becomes a perennial question in an era where analytics improve constantly. Capillary-zone electrophoresis was once considered unreliable for stability testing but now has become more robust. The technique’s high sensitivity and resolving power are compelling, but that is a good news, bad news proposition because the more one sees, the more questions one (or one’s regulatory reviewer) will ask.
Developers of biotherapeutics should, therefore, be prepared for long discussions with regulators, especially for new molecules, warns Dr. Waite of Tepnel. “But in the end, each sponsor must be prepared to make their own case for stability.”