Companion diagnostics CDx are medical devices, specifically a n in vitro diagnostic device IVD , providing important information regarding the safe and effective use of therapeutics. The Food and Drug Administration FDA ascribes them three crucial functions: 1 identify patients more likely to benefit from a therapeutic; 2 determine patients at increased risk of serious side effects; and 3 monitor treatment responses for the purpose of adjusting dosage or regimens to improve safety and effectiveness.
In our estimation, CDx act as a compass that directs the healthcare provider to the most appropriate treatment for each patient 1.
This milestone marked the birth of the drug-diagnostic co-development model , a transformative approach that has since witnessed consistent and substantial adoption 2. However, over the next 14 years, CDx advancement was slow, with the majority of new approvals occurring only in the past decade. In fact, from to , approximately 20 new CDx were approved, whereas from to , that number rose to 3. Despite the historical tendency toward oncology products, applications in rare diseases and metabolic syndromes are evolving, paving the way for CDx to become an intrinsic part of precision medicine clinical trials across many indications.
The use of a companion diagnostics strategy in clinical trials, which we define here as using one or more biomarkers to pre-select and enroll patients more likely to respond to the experimental therapy, is commonly employed in oncology.
In these trials, identification and pre-selection have significant advantages, allowing smaller patient groups to power the statistical analysis, potentially reducing overall costs, and increasing the likelihood of approval 4.
