An oral alternative to anti-tumor necrosis factor injections and infusions showed positive results in a phase 2 trial of mild-to-moderate ulcerative colitis, the manufacturer Protalix BioTherapeutics announced.
“These initial efficacy results for OPRX-106 are very impressive as they represent clear clinical benefits,” Yaron Ilan, MD, chairman of the department of medicine at The Hadassah Hebrew University Medical Center in Jerusalem, said in a press release. “Orally administered OPRX-106 is a tremendous step forward with the potential benefit of 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.”
OPRX-106 is a “novel proprietary plant cell-expressed recombinant human tumor necrosis factor receptor II fused to an IgG1 Fc domain (TNFRII-Fc),” according to the press release. The plant cells work as a natural delivery capsule through the digestive tract, “having the unique attribute of a cellulose cell wall, which makes them resistant to degradation compared to proteins produced via mammalian cell expression systems.”
In the phase 2 open-label clinical trial, Ilan and colleagues randomly assigned 24 patients to receive 2 mg or 8 mg of the study drug once daily for 8 weeks.
Interim data on the first 14 patients who completed the study (four of whom are currently in treatment and follow-up) showed 57% achieved clinical response and 36% achieved clinical remission at week 8. Additionally, 79% showed improvement in rectal bleeding scores, and most patients showed improvements in other efficacy endpoints (86% achieved improvement in fecal calprotectin, and 64% showed an improved Geboes score).
The study drug was also well tolerated and most adverse events were mild to moderate and transient, the most common of which were headaches.
“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,” Moshe Manor, Protalix’s president and CEO, said in the press release.
Protalix plans to report full study results by the end of the first quarter of 2018.
The company also recently “successfully expressed a plant cell based anti TNF alfa protein comparable to adalimumab (Humira, [AbbVie]) for oral administration,” according to the press release.
Disclosures: Manor is employed by Protalix. Healio Gastroenterology and Liver Disease was unable to confirm Ilan’s relevant financial disclosures at the time of publication.