By Van Waffle
Several potential drugs to treat celiac disease are currently in clinical trials. This comes as welcome news to many patients who have trouble adhering to the gluten-free diet or continue to experience troubling symptoms despite their best efforts.
Clinical trials are the last few steps of research that test medications in human subjects before they are recommended for approval by the United States Food and Drug Administration (FDA). The study of ALV003 from Alvine Pharmaceuticals reported above is a phase II clinical trial.
Another company, Alba Therapeutics of Baltimore, Maryland, recently announced a different experimental drug, larazotide acetate, has come through phase IIb trials with positive results. The FDA has designated this drug for a fast track, meaning it could receive accelerated approval.
Study trials are the culmination of years of research. A drug must first undergo extensive testing in animals or human cell cultures to find out if it is safe. It must also provide enough benefit to justify the immense time and resources that go into human testing.
Even if recommended for clinical trials, many good ideas stall at this point. Various estimates place the cost of the final research, development and approval process at around $1.3 billion.
This presents a bigger obstacle for celiac disease research than high-profile diseases that receive greater financial attention. However, a few pharmaceutical companies have taken on the celiac disease challenge.
Reaching clinical trials by no means indicates a drug is close to approval. In fact, the vast majority never get beyond phase I, which involves testing the drug for safety in a study group of usually less than 100 patients.
The next phase is often broken down into two steps, sometimes combined. Phase IIa tests various doses to determine how much should be taken, and phase IIb determines how well the drug performs at the prescribed dose. Both phases involve study groups of a few hundred people.
For its phase IIb trial, Alba Therapeutics tested larazotide acetate in 342 patients with celiac disease who remained sick after adopting a gluten-free diet. The trial began last fall, and in February the company announced a successful result. Early research had indicated the drug could close tight junctions between cells in the intestine, reducing the body’s immune response against gluten. At press time, Alba Therapeutics’ phase IIb data had not yet been released for publication, and the study had not received a peer review from other scientists.
The next step for a drug is a phase III clinical trial. This normally involves a much larger study involving more than 1,000 patients at multiple health centres. It determines whether the drug provides significant benefit and receives a good response from patients in the course of normal health care.
The FDA’s cautious approach often requires a drug to undergo two phase III trials for approval. Although the FDA allows phase III candidates to be sold under new drug guidelines, many pharmaceutical companies choose not to market them until phase III is successful.
Considering larazotide acetate’s fast-track status and the lack of any other drug therapy for celiac disease, it may become available fairly soon.
