C-Path’s Transplant Therapeutics Consortium Receives EMA Qualification Opinion for iBox Scoring System

The iBox Scoring System is available for use in kidney transplant clinical trials as a novel secondary endpoint prognostic for allograft loss.

TUCSON, Ariz., Dec. 20, 2022 — Critical Path Institute (C-Path) announced today that its Transplant Therapeutics Consortium (TTC) received a qualification opinion for the iBox Scoring System as a secondary efficacy endpoint in clinical trials investigating novel immunosuppressive medicines in kidney transplant patients. This regulatory milestone was achieved through the European Medicines Agency’s (EMA) qualification of novel methodologies for drug development and is the first qualified endpoint for any transplant indication. With this successful qualification, the transplant community is one step closer to having new therapies that better the lives of transplant recipients.

As stated in the qualification opinion, “The CHMP encourages the use of the iBox scoring system as a secondary endpoint in future trials of kidney transplantation and further development of the scoring system targeting a potential future qualification as a surrogate endpoint.”

Long-term graft survival is an important unmet need for kidney transplantation recipients, and new ISTs are needed to improve kidney transplant outcomes. The iBox Scoring System can now be used to evaluate the efficacy of novel treatments intended to improve long-term allograft survival. Specifically, the iBox Scoring System can now be used to demonstrate the superiority of a novel therapy to the standard of care from six to 24 months post-transplant in pivotal or exploratory drug therapeutic studies.

“Improving long-term renal allograft survival remains a major unmet need and developing new immunosuppression treatments requires new approaches to clinical trials,” said Mark Stegall, M.D., Clinician Investigator, Department of Surgery, Mayo Clinic Rochester. “Improving graft survival likely would have a positive impact not only on the individual patient (reduced mortality due to graft failure and reduced need for a second transplant) but also increase the number of kidneys available for other transplant candidates.”

To assist sponsors in designing clinical trials using the iBox Scoring System as an endpoint, TTC developed a sample size calculator using iBOX scores. With this tool, sponsors can apply various inclusion/exclusion criteria and other specifications to better understand how group differences in iBOX parameters translate to a difference in iBOX scores. “This sample size calculator is publicly available HERE to benefit the kidney transplant community and improve future clinical trial efficiency,” said C-Path’s TTC Executive Director, Amanda Klein, Pharm.D.

In 2017, C-Path started TTC in partnership with the American Society of Transplantation (AST) and the American Society of Transplant Surgeons (ASTS) aimed at accelerating the medical product development process for transplantation. “This EMA qualification opinion is a result of many years of extensive work and extraordinary collaboration and would not have been possible without the international transplant community’s ongoing collaboration, data sharing, expertise and dedication,” said Shandie Covington, AST Executive Director. “We are grateful to our many collaborators for their continued support. We look forward to the impact this qualified endpoint will make in developing novel therapies focused on long-term graft survival in kidney transplantation,” said Maggie Kebler-Bullock, ASTS Executive Director.

This regulatory qualification achievement was accomplished by employing the resources of the TTC members and engaging with EMA throughout the qualification process. TTC is supported through funding and input from the American Society of Transplantation, American Society of Transplant Surgeons, argenx, Bristol Myers Squibb, CareDx, CSL Behring, Eledon Pharmaceuticals, the European Society for Organ Transplantation, the U.S. Food and Drug Administration (FDA), Hansa Biopharma, Immucor, National Institutes of Health, Novartis, Sanofi, Takeda, Talaris Therapeutics, Thermo Fisher Scientific, The Transplantation Society, Transplant Genomics and Veloxis Pharmaceuticals.

TTC is also working on its next regulatory milestone: the regulatory endorsement of the iBox Scoring System as a reasonably likely surrogate endpoint by the FDA, to whom the Qualification Plan has been submitted and is under review.

As part of the 21st Century Cures Act, passed into law in December 2016, public-private partnerships consisting of government entities, including FDA, the biopharmaceutical industry, health care providers, academic researchers and patient advocacy organizations, have been encouraged to work together to foster innovation in the development of new therapies by qualifying new drug development tools that can accelerate the process of making new therapies available to patients. Any groups that would like to join in this effort, or have information or data that may contribute to further advances, can contact Amanda Klein (aklein@c-path.org).

The qualification opinion can be found on the EMA website, or on the TTC website here.



Transplant Therapeutics Consortium (TTC) was launched in April 2017 and co-founded by the American Society of Transplantation (AST) and the American Society of Transplant Surgeons (ASTS). TTC brings together pharmaceutical companies, diagnostic companies, academic and nonprofit partners working toward a common goal of moving the field forward toward drug development solutions in transplantation. TTC is managed and supported by the Critical Path Institute (C-Path).
For more information, visit c-path.org/ttc.


Critical Path Institute (C-Path) is an independent, nonprofit organization established in 2005 as a public and private partnership. C-Path’s mission is to catalyze the development of new approaches that advance medical innovation and regulatory science, accelerating the path to a healthier world. An international leader in forming collaborations, C-Path has established numerous global consortia that currently include more than 1,600 scientists from government and regulatory agencies, academia, patient organizations, disease foundations, and hundreds of pharmaceutical and biotech companies. C-Path U.S. is headquartered in Tucson, Arizona, C-Path in Europe is headquartered in Amsterdam, Netherlands and C-Path Ltd. Operates from Dublin, Ireland with additional staff in multiple other locations. For more information, visit c-path.org.

Critical Path Institute is supported by the Food and Drug Administration (FDA) of the Department of Health and Human Services (HHS) and is 55% funded by the FDA/HHS, totaling $17,612,250, and 45% funded by non-government source(s), totaling $14,203,111. The contents are those of the author(s) and do not necessarily represent the official views of, nor an endorsement by, FDA/HHS or the U.S. Government.

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