Frankfurt Bad news packed in protein. This is how British biologist Peter Medawar once described the function of viruses. In the case of the Sars-CoV-2 virus, the bad news is written on an RNA strand that the pathogen infuses into the cells of the respiratory tract in order to reprogram it for the production of new viruses.
Two young biotech companies – the Munich company Ethris and the Zurich neurimmune – want to use a very similar technique to combat the corona virus. Their concept is also to package RNA and deliver it to the lungs as an aerosol. In this case, however, the RNA is not encased by proteins, but by lipid molecules. And instead of bad information, it should contain the building instructions for an effective defense mechanism, i.e. for so-called antibodies against the coronavirus.
“We want to put a protective antibody layer over the lung cells”, the Ethris founders Carsten Rudolph and Christian Plank describe the project of the two companies. The charm of the concept: In this case, the medicine would be delivered in the form of a spray to where it is most urgently needed, in the lungs. And the drug would not contain the actual active ingredient, just the blueprint for it in the form of a specially prepared messenger ribonucleic acid (mRNA).
The biomolecule mRNA plays a central role in cell metabolism by translating genetic information into protein substances (proteins). In recent years, pharmaceutical researchers have increasingly become the focus of attention after some companies have developed processes that could use mRNA as a drug. Some experts see it as a kind of software that can be used to control cells in any direction.
Around a dozen biotech companies – including the German companies Curevac and Biontech – are now working on specific drugs and vaccines made from mRNA. The corona crisis gives them additional impetus, also because the technology promises a comparatively quick generation of drug and vaccine candidates.
Regardless, it is too early to speak of a validated class of agents. Potential mRNA drugs are still at a relatively early stage of development and are subject to some uncertainties. There is still no approved drug or vaccine in the world that consists of mRNA. As far as clinical trials are running, they are almost always in the first of three trial phases.
We take advantage of the evolution of the human immune system by taking millions of years of optimization. Roger Nitsch, neurimmune chief and founder
The product development of Ethris and Neurimmune is also just at the beginning. Nevertheless, the companies are confident that they will be able to identify the blueprint for a highly effective antibody over the next few months and will be able to start clinical trials with a spray against Covid-19 in the fourth quarter of 2020. “This is a unique combination of expertise to provide a therapeutic option for patients as quickly as possible,” said Ethris co-founder Rudolph.
The cooperation between the two companies is also a typical example of how pharmaceutical and biotech companies are bundling complementary skills these days in order to develop drugs against the corona pandemic as quickly as possible. Ethris, founded in 2009, has been working on RNA-based drugs against lung diseases such as COPD, asthma or fibrosis for a long time, and is cooperating in this area with the British pharmaceutical giant Astra-Zeneca.
The Swiss neurimmune, on the other hand, sees itself as a specialist in the analysis of immune cells and the selection of antibodies from these cells. In this way, the company, which was founded in 2006 as a spin-off from the University of Zurich, discovered, for example, the antibody aducanumab, currently the most prominent drug candidate for Alzheimer’s, for which the US company Biogen has recently applied for approval in the United States.
Selection of antibodies
Antibodies are complex protein molecules that can bind to other molecules particularly precisely. For many years, biotechnologically produced antibodies have been used in medicine primarily as active substances against cancer and rheumatism.
In the human body, the B cells of the immune system produce a wide variety of antibodies to ward off foreign bodies and microorganisms. The antibodies are gradually optimized and thus form an important element of the immune system. This also applies to the natural immune response against the corona virus.
It is precisely these properties that neurimmune tries to take advantage of. “Our technology is characterized by the fact that we can analyze the B cells of healthy people and use them to identify specific gene sequences that code for antibodies, which in turn can be used in sick people,” describes neurimmune boss and founder Roger Nitsch Strategy of the Zurich biotech company. “We are taking advantage of the evolution of the human immune system by taking millions of years of optimization.”
According to Neurimmune, an average of around 100 different antibodies against the pathogen are found in the blood of a person who has survived Covid-19 disease. Doctors also use this property, for example, to treat seriously ill Covid-19 patients with the blood plasma of convalescents.
Number of the day
against the pathogen can be found in the blood of a person who has survived Covid 19 disease. (Source: Neurimmune)
The experts at the Swiss biotech company, on the other hand, do not aim at a mixture of antibodies, but at the selection of a single, particularly effective specimen that not only binds to the virus, but also makes it harmless. For example, it eliminated its ability to penetrate the lung cells. In this case, biologists speak of “neutralizing” antibodies. They are considered the decisive weapon against the pathogen.
In order to find the gene sequence for such a super-antibody, Neurimmune says it currently analyzes two to three million B cells from cured Covid-19 patients per week using the high-throughput method. “We want to test until we have the optimal molecule,” says Nitsch.
Such an antibody, which is filtered out of the blood of healthy people, also has the advantage from the perspective of the neurimmune boss that it causes particularly few side effects. In principle, the immune system also optimized it in this regard.