Today is World Cancer Day, a day that aims to raise awareness about this dangerous disease that affects millions of Americans every year. Let us take this opportunity to take stock of the latest most promising treatments and those that are soon to be available.
Immunotherapy drugs, which alter the function of the immune system so it can recognize cancer cells, have revolutionized cancer treatment over the past decade. But they are effective in only about 25% of patients, with wide variation depending on the cancer type.
Currently about 80% of the molecules or therapeutic treatments in development for cancer are immunotherapies. In particular, researchers are testing the combination of chemotherapy followed by immunotherapy, which for the first time has induced mutations in cancer cells that then make them easier for the immune system to find. Much hope also lies in so-called checkpoint inhibitor treatments, which attempt to wake up killer lymphocytes already in the tumors but dormant. This approach has already significantly improved the prognosis for melanoma and lung cancer.
These treatments represent hope for the 10% to 15% of women with triple-negative breast cancers for which there is currently no effective treatment. A study of Durvalumab (a drug marketed by AstraZeneca for certain lung cancers) recently published in Nature Medicine showed that this antibody can improve survival in women with this type of cancer.
A vaccine to cure cancer?
Current studies are also investigating the efficacy of a vaccine with a therapeutic, rather than preventive, effect. This is the path that the French biotechnology company Transgene intends to follow with a vaccine against the HPV (papillomavirus) virus in combination with conventional immunotherapy. Another trial with a tailored vaccine from the same laboratory has just begun to treat patients with head and neck cancer.
This treatment consists of equipping the immune system with the ability to recognize a tumor, based on genetic mutations specific to each patient, to be able to identify cancer cells and trigger a specific immune response. The label of vaccine comes from the fact that, unlike with other immunotherapies, they are actually trying to target proteins that are not expressed by normal cells but only by cancer cells. The goal is to develop a vaccine against these proteins so that the body becomes immune to them.
Improved treatment targets
Morphological and, increasingly, genetic analysis of the tumor and its surrounding cells plays an important role in determining a patients’ prognosis, as well as the treatment that fits them most. The presence of certain mutations in the DNA of the cancer cells, as well as the distribution of immune cells especially lymphocytes, make it possible to predict whether this type of treatment will be effective. Most importantly a better targeting of treatments to avoid unnecessary side effects for patients is really the biggest challenge and should be the ultimate goal.
Nanoparticles to improve existing treatments
Another promising approach involves optimizing the effectiveness of existing molecules by encasing them in lipid nanocapsules. The goal is thus to better distribute the drugs so that they enter directly into tumor cells and prevent damage to normal cells, thereby reducing the toxic effect on the body.
Promising clinical trials at the Institut Curie showed that the injection of metallic nano beads into tumors increases the effectiveness of radiotherapy.
With a different approach, in the US researchers are using genetically modified bacteria to administer a toxic cocktail in the center of tumors to get the medication right where it is needed. To clarify it is important to get the toxic cocktail directly inside the tumors because they are less vascularized and as a result chemotherapy molecules are not able to reach them in a high enough concentration to destroy them.