From BZ
Is it the beginning of the end for the horror disease?
In Germany alone, around 240,000 people die of cancer every year. The local biotechnology company Biontech from Mainz has now landed a new coup – and is raising great hopes.
After the Biontech founders Uğur Şahin (58) and Özlem Türeci (56) brought the world’s first corona vaccine onto the market (an idea from cancer research), they presented the first study results for their cancer vaccine CARVac on Monday:
Tumors could be stopped in their growth and sometimes even shrunk. Back to the roots! Because when Biontech was founded 15 years ago, the research couple wanted to develop novel drugs against cancer. The vaccination is also based on mRNA technology. In short: By introducing a certain protein into the cell, the body can repair it itself.
The study numbers are encouraging: 44 patients received the new vaccine in four dosage levels. After just two, an interim situation was established.
► Effect of two dosage levels: In 59 percent of the test subjects, the tumors shrank by at least 30 percent. In almost all patients (95 percent) the cancer was stable after vaccination. This means that the tumor stopped growing.
► Effect of four dosage levels: Here the “success rate” was somewhat lower. But: In at least 45 percent of the patients, the tumors shrank by at least 30 percent. And: The cancer was stabilized in at least 74 percent of all patients.
Reason for the drop in numbers: With four dosage levels, the data from 38 patients could be reliably evaluated, with two dosage levels only from 13 patients.
What about side effects?
During the course of vaccination administration, a dose-dependent increase in inflammatory reactions was observed in 23 of the 44 test subjects. In most cases it was fever, low blood pressure. Two patients experienced prolonged symptoms, in one case even life-threatening symptoms.
Basis of CAR T-cell therapy
CAR T-cell therapy (“CAR” stands for “chimeric antigen receptor”) is a form of immunotherapy in which the body’s own defense system is intended to target tumor cells. The CAR receptor is manufactured in the laboratory and fits perfectly onto certain docking structures of cancer cells.
For the therapy, blood is taken from the patient and the white blood cells (leukocytes) it contains, which are responsible for our body’s defense system, are filtered out. The so-called T cells are then extracted from this, equipped with the CAR receptor and administered to the patient – via infusion. There you should dock onto the tumor cells and fight them.
So far, this form of therapy has been used to treat leukemia, for example. However, it was not particularly successful against solid tumors.
Because: Until now, the CAR-T cells have not always been able to correctly recognize the tumor cells that need to be combated and therefore have not been able to combat them effectively. And: Due to the short “durability”, the CAR-T cells quickly exhausted and died before they could destroy the cancer cells.
New mRNA additive against cancer
That’s why BioNTech is now relying on a new mRNA vaccine in combination with CAR T-cell therapy. This attacks the protein claudin-6, which is produced by carcinomas.
The mRNA, i.e. the genetic information of claudin-6, is transported into the cancer cells, where the protein is then produced. The resulting product, an antigen, reaches the surface of the cancer cells, where it can be easily recognized and combated by the CAR-T cells. Another highlight: The vaccine strengthens the CAR-T cells, which can therefore effectively attack the cancer.
In previous studies on mice, this has proven to be effective: the animals’ tumors regressed significantly within two weeks. Now the first results from a combined phase 1 and 2 human study have been announced.
It is still unclear whether and when the vaccine will be approved throughout Germany. A phase 2 study is to be started in 2024 using the findings so far, in which the effectiveness and dosage will be further specified.
By Marta Ways & Ferdinand Heimbach