An oral alternative to injectable anti-TNF drugs—a mainstay of inflammatory disease therapy for decades—has shown encouraging activity in a phase 2 trial.
Data from the first 14 patients with mild to moderate ulcerative colitis enrolled into the study of Protalix BioTherapeutics’ OPRX-106 suggest that 57% of them had a clinical response after eight weeks, with more than a third (36%) going into complete remission.
Four out of five patients (79%) showed a significant improvement in rectal bleeding, while 86% had reductions in calprotectin—a biomarker for inflammation in the intestines—and 64% showed an improvement on assessment of the cells lining the GI tract.
Lead investigator Professor Yaron Ilan, M.D., of Hadassah Hebrew University Medical Center in Jerusalem says that the results reveal “clear clinical benefits” with the drug and suggest that it could be a “tremendous step forward” in inflammatory bowel disease.
The Israeli biotech is targeting gastrointestinal inflammatory diseases—estimated to be a $4 billion-plus marketing opportunity—because it believes in these cases injectable anti-TNF treatment is often limited by systemic side effects and can be undermined by the development of neutralizing antibodies.
Local delivery to the gut can focus the activity of the drug at the site of the disease and sidestep those problems, whilst being more convenient for patients and—potentially at least—making it viable as a first-line therapy.
OPRX-106 has the potential to “significantly lower side effects as it does not suppress the immune system while redirecting it in an anti-inflammatory direction, as opposed to the currently approved anti-TNF treatments, all of which are administered via injection or infusion, and carry potential short- and long-term side effects,” Ilan said in a statement.
Protalix expects to report full data from the trial later this quarter, and—if the drug hits the mark in this and further trials—it could be a rival to some of the top-selling drugs, including AbbVie's Humira (adalimumab), which is the biggest pharma product with sales of $16 billion last year.
“We are very excited by these first-in-patient results, which demonstrate that novel, orally administered, OPRX-106 treatment is biologically active in the gut with clear clinical effect,” said Moshe Manor, Protalix’s president and CEO, in the statement.
Protalix isn’t the first company to develop this approach. Avaxia Biologics (acquired by Circle33 LLC) has also been trying to develop an oral anti-TNF drug for GI applications, and said in 2015 that it had a candidate called AVX-470 ready for phase 2 testing, although there has been no update on this program of late.