Norwegian researchers have developed an experimental drug to attack an important molecule that controls cancer cell duplication. Tests have also begun on humans.
Cancer cells have a particularly active metabolism because they are continuously multiplying. However, all this biological activity stresses the cancer cell, which responds by activating a protein in the nucleus, called PCNA - Proliferating Cell Nuclear Antigen, which can play an important role in DNA replication and repairing damage.
This has long been the subject of studies that have clearly shown how PCNA can become an excellent target for treatment: by blocking it, the cancer cell quickly falls victim to its own frantic proliferation and dies off. This has been confirmed by both in vitro and animal testing. PCNA is also present and active in many tumours, but much less so in healthy cells, which are, by definition, more stable.
Progress in the fight against cancer
The first positive results on humans are now here. Researchers at the Norwegian University of Science and Technology (NTNU) who have been working on this molecule for almost 20 years, have begun a clinical trial to test the safety of the first anti-PCNA drug, called ATX-101, developed by NTNU itself and an associated company, APIM Therapeutics.
To do this, they recruited 25 people in Australia with various kinds of tumours that were no longer responding to treatment and administered four different doses of the drug to these patients. The first response was positive, as ATX-101 proved to be relatively safe, causing mild to moderate side effects in 64% of the patients – less severe than conventional chemotherapy. The active ingredient of ATX-101 is eliminated from the body after just one hour and has little effect on healthy cells. ATX-101 also does not appear to cause hair loss or need to be used in combination with other chemotherapeutic agents.
Cancer trials: the first results are positive
As reported in the scientific journal Oncogene, part of the Nature group, studying these patients has also made it possible to gather the first clinical data. The disease was stable in 70% of patients after six weeks. Twelve patients continued the treatment and were stable for 18 weeks, and one woman, who took the drug for 18 months, is still stable after two years.
Of course, these are still early days. Now everything will depend on the next steps, phases 2 and 3 of the trial, which will be conducted on a larger number of patients.
A tendency towards chronic illness
If the results are confirmed to be positive, the therapeutic 'arsenal' for cancer patients may also expand to include drugs like anti-PCNAs, which have a different aim from that of classic chemotherapeutics: stabilising the disease, and thus transforming it into a chronic illness through a single drug with fewer side effects than traditional treatments.