Horsholm, Denmark, October 18, 2016 – Today, ExpreS2ion Biotech Holding AB (“ExpreS2ion”) announces that its collaboration partner, the Jenner Institute of the University of Oxford, initiates a Phase I/IIa clinical trial to assess the safety, immunogenicity, and efficacy of the blood-stage Plasmodium falciparum malaria antigen RH5.1, which is produced in ExpreS2ion’s proprietary platform, ExpreS2.

The Vaccine

RH5.1 is a novel, recombinant malaria antigen developed at the Jenner Institute. It is based on recombinant RH5.1 protein produced in the ExpreS2 platform using Drosophila Schneider 2 cells. RH5.1 is a part of a larger protein complex expressed by the malaria parasite during infection, helping it to invade red blood cells and causing the disease. The RH5.1 vaccine is intended to block red blood cell invasion and thus the progression of the disease.

The study

The present study is funded by Leidos Inc as part of the company’s prime contract with the United States Agency for International Development (USAID) for the creation and testing of malaria vaccines. The clinical trial will include 36-48 healthy UK volunteers. The initial purpose is to assess the safety of the vaccine and the extent of the immune response, as well as to identify the optimal dosing regimen of the vaccine. A following step of the trial will test how effective the vaccine is at preventing malaria by comparing individuals from this study given the best dose of the vaccine will be compared to subjects who have not received the vaccine, when challenged with malaria parasites. The first part of the study will run for at least one year.


Malaria is a major global problem, with 3.2 billion people living at risk of malaria infection. In 2015, malaria was thought to have caused 438,000 deaths, most of which (70%) occurred in children under five years old. Currently, there is no generally approved vaccine available for malaria, which means that there is a great need for a safe, effective malaria vaccine.

The Jenner Institute and the University of Oxford

The Jenner Institute is a research partnership between the University of Oxford and the Pirbright Institute focused on the development of vaccines against major global diseases. The University of Oxford’s Medical Sciences Division is one of the largest biomedical research centres in Europe. The University is rated as the best in the world and it has one of the largest clinical trial portfolios in the UK and great expertise in taking discoveries from the laboratory into the clinic.

CEO Steen Klysner comments

“It is a pleasure to announce the initiation of the blood stage malaria clinical trial by such a highly esteemed collaboration partner, and we are proud that the ExpreS2 platform has become an enabling technology for this exciting project.”

Read the whole press release (pdf)