Clinical pilot study
The safety and efficacy of T-Guard™ was evaluated in a clinical pilot study at the University Medical Center Saint Radboud, Nijmegen in the Netherlands. The main objectives of this study were to determine the pharmokinetics, to detect any serious side effects and to evaluate if T-Guard eliminated the mature T cells responsible for causing GVHD. The encouraging results, showing T-Guard’s clear therapeutic window in the treatment of severe acute GVHD, and other details of the study were published in a leading scientific journal. This generated further interest in the product and contributed towards securing additional support for further research.
Phase 1b/2 study
At the end of 2016, Xenikos completed a 20 patient Phase 1b/2 study in The Netherlands and Germany. The results showed that T-Guard™ had a good safety and tolerability profile and very promising clinical efficacy.
In particular, a high Day 28 complete response rate, an important and commonly used surrogate endpoint for acute GVHD studies, was observed. Additionally, there was a substantial increase in 6-month overall survival compared to historical institutional controls. Xenikos plans to present the top-line study results at a major medical conference during 2017 and is currently preparing the corresponding scientific paper, describing the detailed study results.
Randomised active-controlled Phase 2 study
Encouraged by the positive Phase 1b/2 study, preparations for a randomised active-controlled Phase 2 study are ongoing and the study is scheduled to start Q4 2017. In this study, the safety and efficacy of T-Guard will be compared to best available therapy. Several renowned EU and US transplant centres have already expressed their commitment to participate in this study. Given the major unmet medical need and the promising data seen in earlier studies, assuming the Phase 2 results are also positive, Xenikos plans to discuss with regulatory authorities filing for conditional marketing approval based on these results.
Additional opportunities in GVHD
As a next step, it is envisioned that T-Guard™ could be applied earlier in the course of the disease. There is an increasing number of biomarkers being developed and validated that can be used to identify acute GVHD patients who are at high risk of not responding to steroid treatment. For these patients, it could make sense to add T-Guard to first-line steroid treatment to prevent irreparable damage to the organs and immune system. Also in this setting, the short duration and targeted nature of T-Guard treatment could enable intervention at an early stage of the disease without inducing deep and long-term immunosuppression.
Based on the results observed to date, Xenikos believes that T-Guard has a strong potential to fulfil its promises and, together with other developments that are currently ongoing in the field, to help improve the treatment of patients with this devastating disease.