The success of some drugs depends heavily on their ability to get to the point where the problem is. A team of American researchers has developed a mechanism to deliver the anticancer drug Interleukin-2 (IL-2) directly to its target by implanting small spherical beads that release the substance.

mesothelioma.
Treatment aims to end pleural mesotheliomas. Mesotheliomas are tumors that affect the mesothelium, a tissue that covers most of our organs. The pulmonary mesothelium is also called the pleura. Although it is curable, it is a very aggressive cancer for which we have not found a cure yet.

One of the challenges doctors face when treating this cancer is that it is impossible to completely remove it. Therefore, treatments are designed so that the remnants left behind by the tumor do not spread.

The possibility of treating these remnants via local immunotherapy, a process that relies on administering “relatively high” doses of immunotherapy in the pleural space, represents an interesting perspective for Bryan Burt, one of the researchers involved in this development. A press release.

Good aim.
These implanted “factories” are actually small spherical beads just over a millimeter in diameter made of alginate, a type of salt obtained from algae. These tiny pearls gradually release the active compound, Interleukin IL-2.

IL-2 is a drug used in immunotherapy, a strategy in the fight against cancer, and attempts to restore the immune system and provide it with tools to fight tumors. It works on two additional fronts, first by interfering with the cancer cells’ ability to grow and multiply, and second by causing the immune system to release chemicals that “attract” cells.

IL-2, yes, produces side effects such as increased risk of infection or breathing difficulties. According to the research team, being able to apply the drug locally can help minimize these undesirable effects.

Collaboration.
Combining cancer treatments is becoming common. The researchers also tested the possibility of combining this technique with checkpoint inhibitors, in this case an inhibitor of the PD-1 protein. Concurrent use, improved IL-2 results. The tests were done on mice.

The results were published in an article in the journal. Clinical Cancer Research. He details that treatment with IL-2 alone was able to eradicate tumors in more than half of the treated mice, achieving full efficacy when combined with a PD-1 inhibitor in this regard.

The long journey of treatments.
For now, the experiment only concerns these animal models, so the road ahead for this treatment is long and uncertain. When preclinical trials are finished, treatments must undergo at least three phases of clinical trials where they are judged to be safe, effective and efficient in fighting the disease.

After that, it must go through the scrutiny of drug agencies that have the final say in their approval. This means years of testing and the possibility of treatment failing.

Beyond mesothelioma.
The use of these implants is based on an engineered treatment against ovarian cancer, which is also in the early stages of development and expects to begin clinical trials this year. In both cases, teams of researchers from Texas Rice University were involved.

According to the Spanish Association Against Cancer, mesothelioma in our environment has an incidence of about 0.35 cases per 100,000 people per year and a death rate of five per million. Immunotherapy, for its part, is becoming one of our best weapons against different types of cancer, either alone or in combination with chemotherapy or radiotherapy.

Image | Jeff Fitlow/Rice University