When United States President Barack Obama landed on Cuban soil in March this year, the first sitting American leader to do so since 1959, he came with a shopping list — and it included a lot more than Havana Club rum and Che souvenirs. Near the top of the list was a lung cancer vaccine called CimaVax. Obama, a reformed cigarette smoker, had an understandably keen interest in a drug whose results have been so promising in preventing lung cancer tumours from growing that the US government was determined to bring it home.
In 2013, more than a hundred members of Congress urged the Treasury Department to allow CimaVax to be tested in the US, and in 2015 New York Governor Andrew Cuomo visited Havana to finalise negotiations between Roswell Park Cancer Institute and Cuba’s Centre for Molecular Immunology, where CimaVax was invented, to begin clinical trials in the US. The vaccine could offer high-risk patients an additional eighteen years of life, keeping the deadliest type of cancer cells from growing in lung tissue.
By early June, just three months after Obama’s historic visit, the US Department of Health and Human Services and the government of Cuba had signed a memorandum of understanding to encourage cooperation on health matters.
CimaVax, which is both a treatment and vaccine for lung cancer, has been free to the Cuban public since 2011. Amazingly, the vaccine costs the Cuban government only US$1 per dose to produce. And the drug appears to have no major side effects. “We think it may be an effective way to prevent cancer from developing or recurring, so that’s where a lot of our team’s excitement comes in,” says Dr Kelvin Lee, co-leader of the tumour immunology and immunotherapy programme at Roswell Park Cancer Institute, located in Buffalo, New York. “There’s good reason to believe that this vaccine may be effective in both treating and preventing several types of cancer, including not only lung but breast, colorectal, head-and-neck, prostate, and ovarian cancers, so the potential positive impact of this approach could be enormous.”
CimaVax targets a particular protein called epidermal growth factor, or EGF. EGF occurs naturally in the human body, and signals cells to grow and divide. It does this by attaching to a receptor protein on the cell surface. Some cancers make the body produce too much EGF, so the cells keep growing and dividing uncontrollably.
The CimaVax vaccine is made up of two proteins, one of which is EGF. The vaccine works by stimulating the body’s immune response, encouraging it to make antibodies that recognise and bind to EGF. This stops the EGF attaching to the receptors on cancer cells — so there is no signal telling the cancer cells to grow and divide.
For people who already have lung cancer, this response results in the body actually getting rid of the cancer cells. And for people who are currently healthy but at high risk for lung cancer — for example, someone in remission — the treatment acts as a vaccine to prevent future relapse. To be clear, CimaVax doesn’t cure cancer. It’s a therapeutic vaccine that works by targeting the tumour itself: specifically, going after the proteins that allow a tumour to keep growing. You can’t just take a shot of CimaVax and continue to smoke a pack a day.
Five thousand people have been treated with CimaVax so far, including one thousand patients in Cuba. The latest Cuban study of 405 patients confirms earlier findings about the safety and efficacy of the vaccine. It is possible that CimaVax could one day be a standard preventive vaccine given in childhood, like polio, measles, mumps, and rubella.
The Centre for Molecular Immunology in Havana is the heart of Cuban biotechnology innovation. Devoted to basic research and product development, the centre has extensive experience in the field of monoclonal antibodies. With 1,200 employees, mostly scientists and engineers, the centre’s main research objective is the development of new products for the diagnosis and treatment of cancer, and other diseases related to the immune system. The focus is on cancer immunotherapy, especially the development of molecular vaccines, including antibody engineering, cellular engineering, bio-informatics, and regulation of the immune response.
“They are a very innovative group of scientists, and they have vaccines and drugs that we think could play a very significant role in our fight against cancer,” says Candace Johnson, CEO of Roswell Park. “We’re delighted to be working with them, and we hope very soon that we can start our trial on CimaVax — hopefully the first of many clinical trials to be done with some of these Cuban vaccine approaches.”
How did tiny Cuba, with few resources, create a cancer vaccine that the US wants so badly? Ironically, it is precisely because of the US trade embargo that Cuba has been forced for the last fifty years to innovate and make do with very little. Its biotech industry is one of the success stories of the Revolution. “They’ve had to do more with less,” muses Johnson. “So they’ve had to be even more innovative with how they approach things. For over forty years, they have had a preeminent immunology community.”
Average life expectancy for Cubans is seventy-nine years, on par with the US. While many drugs and even anesthetics have been hard to come by over the years, Cuba has one of the best doctor-to-patient ratios in the world. More important, the government has invested in primary care for citizens, public education, housing, and nutrition, where the focus is on preventing diseases.
The US and Cuba’s health MOU states that the two former Cold War enemies will now work together on global health issues, including dengue, zika, and the challenges of ageing. Cuba is home to one of the World Health Organisation’s collaborating centres on dengue. The island has had comparatively few indigenous zika cases, which they credit to their mosquito-control programmes developed from dealing with dengue.
“Cuba has made significant contributions to health and science, as evidenced by their contribution to the ebola response in West Africa and becoming the first country to eliminate mother-to-child HIV transmission,” said US Heath and Human Services Secretary Sylvia Mathews Burwell in a statement. “This new collaboration is a historic opportunity for two nations to build on each other’s knowledge and experience, and benefit biomedical research and public health at large.”