A group of Danes and Canadians came across something very surprising when they were testing a new anti-malaria drug for pregnant women. The vaccine turned out to eliminate not only malaria, but also more than ninety percent of the cancers tested.
Malaria researcher Ali Salanti from the University of Copenhagen made a spectacular discovery. The compound oncophetal chondroitin sulfate, which has long been known to occur in placental cells (and leads to rapid growth), is also found in cancerous growths. The placenta (placenta) is formed by the developing fetus to withdraw nutrients from the mother's circulation and release waste products. The placenta has to grow very quickly, which is why the fetus makes this connection. This is also the reason that the compound occurs in cancerous growths. After this discovery, Salanti signaled his classmate Mads Daugaard, now a cancer researcher. This led to cancer research.
How does the drug work?
The drug consists of two components. The first component attaches to a certain carbohydrate, oncophetal chondroitin sulfate, which only occurs in cells of the placenta (and, as the group has now discovered, also in cancer cells). Once the component has attached itself, the second component is released. This is a poison molecule that kills the cell. Chemotherapy does nothing else, but this drug specifically targets only cells with the carbohydrate compound in the cell membrane. This means that the patient has little or no suffering from the serious symptoms of poisoning that chemotherapy entails.
Malaria parasites like to attach themselves to placental tissue and make a special protein that binds to this carbohydrate. The researchers copied this protein and attached the poison molecule to it.
What has the drug been tested in?
The agent has been tested in vitro, in petri dishes, and in mice implanted with the human cancerous tumors. Both in vitro and in the test animals, the drug was found to eliminate more than ninety percent of the tumors. The drug was found to dramatically increase survival: of the six mice treated, five were still alive after three injections. None of the control group survived.
Are there any drawbacks to the drug?
The most obvious drawback, of course, is that pregnant women cannot use the drug. This would induce a spontaneous abortion. This also applies to classic chemotherapy. As it stands, the agent has only been tested on tumors cultured in vitro and in mice. The researchers estimate that, in the most optimistic case, it will take at least four years for clinical trials on humans to begin.
Wat is de stand van zaken?
In 2019 zijn klinische proeven begonnen . Vooralsnog alleen bij vrouwen met malaria om hun toekomstige foetus te beschermen tegen de malariaparasiet. Is het vaccin eenmaal veilig bevonden, dan zou het ook als middel tegen kanker kunnen worden getest. Een langduirige toelatingsprocedure is dan immers niet meer nodig omdat het een bestaand geneesmiddel is.
1. A. Salanti et al., Targeting Human Cancer by a Glycosaminoglycan Binding Malaria Protein, Cancer Cell, 2015
2. Malaria vaccine provides hope for a general cure for cancer, Copenhagen University News, 2015
3. B. Mordmüller et al., First-in-human, Randomized, Double-blind Clinical Trial of Differentially Adjuvanted PAMVAC, A Vaccine Candidate to Prevent Pregnancy-associated Malaria, Clinical Infectious Diseases, Volume 69, Issue 9, 1 November 2019, Pages 1509–1516, https://doi.org/10.1093/cid/ciy1140