A new nano-vaccine is showing promising results in treating skin cancer in mouse models. Developed by scientists at Tel Aviv University, the prospective vaccine encases two experimental new cancer drugs inside a tiny nanoparticle, with initial experiments revealing the therapy can both stimulate the immune system to kill melanoma, and act as a preventative vaccine stopping the cancer from developing in the first place.

"The war against cancer in general, and melanoma in particular, has advanced over the years through a variety of treatment modalities, such as chemotherapy, radiation therapy and immunotherapy," explains Ronit Satchi-Fainaro, lead on the new study, "but the vaccine approach, which has proven so effective against various viral diseases, has not materialized yet against cancer."

The new research describes the development of tiny nanoparticles that are filled with a combination of two novel experimental cancer drugs, an anti-PD1 antibody and an anti-OX40 antibody. Both molecules are designed to stimulate the body's immune system to attack tumor cells and are encased in tiny biodegradable polymers called mannosylated nanoparticles.

This nano-vaccine was tested on two different kinds of mouse models. When administered to animals with an initial melanoma the treatment was found to notably delay the progression of the disease. But, most interesting was the study revealing the treatments preventative effects. When administered to healthy mice the vaccine seemed to prevent the animals from developing melanoma even after being injected with melanoma cells.

"The result was that the mice did not get sick, meaning that the vaccine prevented the disease," says Satchi-Fainaro.

In further laboratory tests the research showed the treatment to be effective on human metastatic melanoma cells – in this instance, cells taken from patients with melanoma brain metastases. It is very early days for the research, and of course it hasn't yet been shown to be effective, or safe, in human patients so don't expect to see a clinical outcome for at least 10 years. However, as a proof-of-concept model demonstrating the potential for effective nanoparticle cancer vaccines, the research is certainly compelling.

"Our research opens the door to a completely new approach – the vaccine approach – for effective treatment of melanoma, even in the most advanced stages of the disease," says Satchi-Fainaro. "We believe that our platform may also be suitable for other types of cancer and that our work is a solid foundation for the development of other cancer nano-vaccines."

The study was published in the journal Nature Nanotechnology.

Source: Tel Aviv University