OPRX-106 is a TNF inhibitor that Protalix scientists grew from a plant cell to resist gastrointestinal degradation better than proteins from animals cells.
TNF inhibitors are used worldwide to treat inflammatory bowel disease, which includes Crohn’s as well as ulcerative colitis. They reduce inflammation and stop disease progression by targeting an inflammation-causing substance called tumor necrosis factor, or TNF.
Most anti-TNF drugs are administered by injection, but OPRX-106 is a pill.
Before OPRX-106 entered clinical trials, studies in mice showed it could alleviate bowel diseases. It improved symptoms and increased blood levels of anti-inflammatory biomarkers.
The Phase 2 trial (NCT02768974) included 24 patients with mild to moderate ulcerative colitis. Patients were randomized to receive either 2 mg or 8 mg of OPRX-106 once a day for eight weeks.
Eighteen of the patients completed the trial. OPRX-106 was found to be safe and well tolerated, with headaches the most common adverse event.
Sixty-seven percent of patients’ ulcerative colitis improved significantly from the treatment. At week eight, 28 percent of patients’ disease had gone into remission — that is, they were symptom-free.
In addition, 72 percent of patients’ rectal bleeding decreased. The same percentage had less fecal calprotectin, a biomarker of gastrointestinal inflammation.
Microscope examination of intestinal tissue showed that disease-related inflammation improved in 61 percent of patients.
Importantly, scientists did not detect any anti-drug antibodies.
“We are very excited by these results,” Moshe Manor, Protalix’s president and chief executive officer, said in a press release. “They demonstrate efficacy and a lack of [an unwanted immune response against the therapy], together with a favorable safety profile.” The safety results mean that OPRX-106 “could potentially overcome one of the most challenging drawbacks of current ulcerative colitis therapies administered via injection and infusion,” he said.
“The data is very encouraging, suggesting that OPRX-106 could potentially address a large unmet medical need in the treatment of ulcerative colitis,” said Professor Yaron Ilan, chairman of the Department of Medicine at the Hadassah Hebrew University Medical Center in Jerusalem.
“OPRX-106 is delivered orally and is biologically active in the gut without triggering the formation of anti-drug antibodies,” Ilan said. It “has the potential to address the partial loss of response seen in anti-TNF alpha treatment, which is driven by the high presence of neutralizing antibodies.”
“By being delivered orally, OPRX-106 could potentially avoid certain side effects, such as malignancies and opportunistic infections, which currently appear in the black box warning of the prescribing information for commercially available anti-TNF alpha biologics,” Ilan added.