Opsona Therapeutics Ltd., the innate immune drug development company, has initiated a phase II clinical trial in renal transplant patients at high risk of delayed graft function with its lead drug candidate OPN-305.

OPN-305 has already been administered to a number of transplant patients at high risk of delayed graft function (DGF) as part of a Pilot study before initiation of this multi-centre, randomized, double-blind, placebo-controlled, parallel group, sequential adaptive phase II trial. This pilot clearly demonstrated that 100 per cent receptor occupancy of TLR2 on circulating monocytes was achievable and durable for the period of ischemia/reperfusion risk. It provided evidence that there was up-regulation of TLR2 in patients and provided the range of doses to be tested versus placebo in the double-blind trial. OPN-305 was well tolerated with no related adverse events. The phase II study which is expected to enrol 278 patients is an adaptive design powered to show a 15-20 per cent absolute benefit of OPN-305 over placebo in reducing the incidence of DGF.

OPN-305 is a novel proprietary humanized IgG4 monoclonal antibody (MAb) against Toll-Like Receptor 2 (TLR2), a target within the innate immune system, and is under development as a treatment for the prevention of DGF following renal transplantation. OPN-305 has orphan status in the EU and USA for solid organ transplantation. Other therapeutic indications are being explored in addition.

Opsona has identified the prevention of DGF following renal transplantation as the first clinical indication for the development of OPN-305. Delayed Graft Function is a serious complication that can increase the risk of organ rejection in the immediate post-operative period of kidney transplants and can range from 45-60 per cent in high risk donor kidneys. Opsona believes that OPN-305 has the potential to be first and best in class in the prevention of DGF and will also provide a novel treatment option for a much wider variety of human diseases, including acute kidney injury, transplantation of other organs, cancer, cardiovascular disease and others.

Commenting on today’s announcement, Mary Reilly VP Pharmaceutical Development and Operations of Opsona Therapeutics said, “It’s exciting to see cutting-edge science offering the prospect of a real breakthrough in life expectancy and quality post transplantation. OPN-305 was granted ‘orphan’ status for solid organ transplantation, in recognition of its rarity and the fact that there are no other comparable treatments being developed. OPN-305 could be a potential first and best in class candidate to reduce this complication. Developing a novel product for an unmet clinical need and working with world class global key opinion leaders in the transplant community is highly motivating and gives all the project partners a sense of urgency about this collaboration.”

Dr Robert Miller, chief medical officer of Opsona commented, “This study represents a real opportunity to improve early graft function in patients offered kidneys from older donors and enlarging the pool of potential organs for patients with end-stage renal disease. We are very pleased with the enthusiasm of the transplant community who have readily agreed to participate in this process.”

Opsona is focused on novel therapeutic approaches to key targets of the innate immune system associated with a wide range of major human diseases, including autoimmune and inflammatory diseases, solid organ transplantation, cancer, diabetes, Alzheimer's disease and others.