Medeor Therapeutics announced it had closed on an oversubscribed Series B financing worth $57 million. The round was led by RA Capital Management. New investors included Sofinnova Ventures and 6 Dimensions Capital. They were joined by existing investors Vivo Capital and WuXi Healthcare Ventures.

Founded in 2012, Medeor focuses on discovering, developing and commercializing personalized cellular immunotherapies, with an emphasis on organ transplants. Its product candidates are being developed to minimize or eliminate chronic anti-rejection, immunosuppressive drug approaches used by recipients of living donor transplants.

The financing will be used to push its Phase III clinical program of MDR-101 in living donor HLA-matched kidney transplant patients. It is currently being conducted under a Special Protocol Agreement with the U.S. Food and Drug Administration (FDA), in addition to a Phase IIb trial of MDR-102 in living donor HLA-mismatched kidney transplant patients. The company also plans to begin development of MDR-103 for the induction of delayed immune tolerance and MDR-104 for deceased donor kidney transplant patients.

A Special Protocol Assessment is where the FDA and a sponsor make an official agreement on the protocol design, endpoints and analysis of a Phase III trial before initiation to decide if they adequately address scientific and regulatory requirements for FDA approval.

“Organ transplantation is one of the most remarkable life-giving feats of modern medicine, though patients must deal with intense and sometimes intolerable chronic immune suppression,” said Peter Kolchinsky, portfolio manager and managing director at RA Capital, in a statement. “Based on brilliant insights into human immunology, we believe Medeor may have elegantly transformed this procedure to meaningfully reduce the need for long-term immunosuppression, allowing patients not only to survive thanks to the generosity of a donor but also to enjoy a higher quality of life.”

Also as part of the financing, Kolchinsky and Anand Mehra, general partner at Sofinnova, joined Medeor’s board of directors.

On April 18, Medeor received clearance from the FDA for an Investigational New Drug (IND) application for MDR-101, as well as the Special Protocol Assessment for the Phase III trial. MDR-101 is a first-in-class precision cellular immunotherapy that the company hopes will remove the need for anti-rejection therapies in kidney transplant recipients with a one-time infusion. In earlier trials, it has been shown to create hematologic mixed chimerism, the co-existence of immune cells of both the recipient and the donor. This appears to reprogram the recipient’s immune system to accept the donor kidney.

“The current standard of care to prevent rejection of organ transplants is far from optimal due to unacceptably high long-term failure rates and treatment-associated complications, and new approaches are greatly needed to relieve organ transplant recipients from the litany of undesirable effects associated with anti-rejection drug regimens,” said D. Scott Batty, Jr., Medeor’s chief medical officer, in an April statement.  “MDR-101 has the potential to address the two most critical transplant patient needs: preventing organ rejection and mitigating anti-rejection treatment-associated toxicities. While our first indication is HLA-matched, living donor kidney transplants, the proprietary technology on which MDR-101 is based has the potential for use in all solid organ transplant recipients, regardless of degree of HLA match.”