Protalix BioTherapeutics announced that its novel, oral anti-TNF therapy, OPRX-106, met key efficacy endpoints in a phase 2 trial of patients with mild-to-moderate ulcerative colitis.
“The data is very encouraging, suggesting that OPRX-106 could potentially address a large unmet medical need in the treatment of ulcerative colitis. OPRX-106 is delivered orally and is biologically active in the gut without triggering the formation of anti-drug antibodies. OPRX-106 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,” Yaron Ilan, MD, chairman of the department of medicine at the Hadassah Hebrew University Medical Center in Jerusalem said in a press release. “In addition, 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.”
OPRX-106 is a novel, plant cell-expressed recombinant human tumor necrosis factor receptor II fused to an IgG1 Fc domain (TNFRII-Fc). Protalix said the plant cells work as a natural delivery capsule through the digestive tract and have the benefit of a cellulose cell wall, which makes them resistant to degradation compared with proteins produced through mammalian cell expression systems, according to the press release.
Healio Gastroenterology and Liver Disease previously reported positive interim results from the phase 2 trial announced by the company in January. The company has now reported results on all enrolled patients and plans to share complete data at a medical conference later this year.
In a randomized, open label, two-arm study of OPRX-106, investigators randomly assigned 24 patients with mild-to-moderate UC to receive either 2 mg or 8 mg of OPRX-106 for 8 weeks. The average baseline Mayo score was 7.1 for the 18 patients who have completed the study, with 89% of them having a score between 6 and 9, which would qualify as moderate disease activity, according to the release.
Protalix said 67% of patients experienced a clinical response and 28% achieved clinical remission, meeting two of the study’s key efficacy endpoints.
Additionally, patients reportedly experienced improvement in rectal bleeding (72%), improvement in fecal calprotectin (72%) and improvement in disease activity as measured by the Geboes score (61%).
The drug was well tolerated by patients with only mild to moderate adverse events, the most common of which was headaches.
“We are very excited by these results,” Moshe Manor, president and CEO said in the press release. “They demonstrate efficacy and a lack of immunogenicity together with a favorable safety profile, which could potentially overcome one of the most challenging drawbacks of current ulcerative colitis therapies administered via injection and infusion.”
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.