At the European Crohn´s and Colitis Organisation (ECCO), Prometheus Bioscience presented results from its Phase 2a APOLLO-CD clinical trial of PRA023 in Crohn’s Disease (CD). The presentation highlighted the efficacy and safety of PRA023, an anti-TL1A asset, in the small sample size (N=50) of CD patients. The area of particular interest from this presentation was the reported findings of Prometheus’ proprietary companion diagnostic test (CDx) being evaluated alongside PRA023. If this asset is shown to be effective and advance to the market, the use of the CDx with PRA023 gives the treatment and Prometheus a significant advantage over all CD therapies currently in development and on the market, according to GlobalData, a leading data and analytics company.

Adeleke Badejo, Senior Analyst – Immunology at GlobalData, comments: “A diagnostic test that can accurately select CD patients that have a higher probability of achieving a robust and lasting response to an associated therapy will address an immediate need for an improved process to select the most efficacious and appropriate CD treatment and will likely have rapid adoption by healthcare providers (HCPs).”

A clear issue currently facing gastroenterologists treating CD is the lack of information needed to better determine the most efficacious approved therapies. This issue could be addressed if more companies evaluate their developing pipeline agents against comparators of current approved therapies as opposed to placebo. This will allow HCPs a better view of the strength of an agent, and where it falls along the spectrum of therapies.

However, the widespread adoption of such trials is unlikely, as they increase the probability that the investigative therapy will fail to show significant efficacy and/or improved safety. Considering the current situation, the introduction of a companion diagnostic test with treatment can have a significant effect on the market and physician practices.

Badejo continues: “It can be assumed that if PRA023 reaches the market, the CDx will be part of the routine assessment of new CD patients, which would lead PRA023 to become a viable first-line option.”

The findings of APOLLO-CD showed the efficacy of PRA023 in CD. The agent achieved endoscopic response (26% PRA023 vs. 12% historical placebo estimate, p=0.002) and clinical remission (CDAI < 150 points; 49% PRA023 vs 16% historical placebo estimate, p< 0.001). Additionally, the CDx resulted in improved endoscopic response when used with a CD specific algorithm (CDx+) compared to the pre-specified algorithm (CDx-), 45% versus 13.3% respectively, an observation that will be considered in the development of PRA023 moving forward.

Badejo concludes: “Though PRA023 and the CDx as a treatment model is promising, the feasibility of its use will be determined by the proportion of CD population that are within the subset targeted by the CDx.”