Final FDA Guidance for In Vitro Companion Diagnostics (CDx) was released in August, providing direction for companies seeking to define a regulatory approach to this booming opportunity. According to Transparency Market Research, the global CDx market is expected to be valued at $5.6 billion in 2019 with a CAGR of 18.1% from 2013 to 2019 – creating a very compelling reason for developing a robust regulatory strategy for those seeking to capture or enter the market.
A companion diagnostic regulatory strategy begins with setting initial objectives. From our perspective, this begins with identifying one of the primary directives from the Guidance document relating to Company/FDA interaction – preparing for a FDA meeting on the project – sooner than later! If this is the primary objective, then preparing for this initial meeting requires setting up a task list that reflects the spirit and directives communicated within the new FDA Guidelines. Going to the FDA before implementing a concrete development plan may be something new (especially to the device people) but has been made very clear by the new Guidance document.
In the past, the relationship between therapeutics and diagnostics (Dx) were more directed toward collecting the data required by the FDA for drug development and approval. Additionally, the Dx might also be used after a drug has been approved, for the purposes of selecting the right drug or to track and optimize a certain regimen that is unique to each patient. Today, however, Dx’s are now being viewed as an important tool – an essential tool – to monitor a drug’s safety and effectiveness, especially if a potential side effect is likely. This heightened level of purpose has ushered in the concept of a “companion” diagnostic, or CDx.
With this in mind, the new regulatory implications bring the spotlight onto defining the CDx much more thoroughly, and earlier, than what has typically been followed previously. To begin with, clarify your diagnostic’s connection to the therapeutic:
These two aspects have obvious and profound implications on the development of, and communication of, the overall product development path. This product development plan is one of the most important aspects the FDA will discuss with any CDx submission. Remember, the FDA’s primary interest is that the therapeutic and CDx would be developed, submitted and approved contemporaneously.
Finally, begin to clarify how the CDx would be used practically within the context of the therapeutic:
This second set of parameters has similar implications to the product development path. In the past, a Dx might have a go/no-go result (e.g. a “positive” test result means you must re-visit the doctor and proceed with more invasive testing – leading to the possible use of a therapeutic), but the CDx implication is viewed as essential and on going to the safe and effective use of the therapeutic.
In summary, the implications of the CDx regulatory pathway will require a very structured and well-managed approach. This may be something drug developers are more familiar with (following normal pre-IND submissions and discussions), but not necessarily those of device developers (pre-IDE). Seeking outside assistance to help in the process can be advantageous, as mapping the device development into a “normal” therapeutic Phase I, IIA, IIB and III will be something of greatest importance to the Regulating Body.