President Barack Obama became the first president to visit Cuba in almost 90 years when he and first lady Michelle Obama traveled to the island nation in March. But one of the most exciting things about the thawing of relations between Cuba and the U.S. is happening stateside right now: the possibility of clinical trials on a drug to prevent lung cancer, and possibly other cancers, too.

CimaVax, which is both a treatment and vaccine for lung cancer, has been researched in Cuba for 25 years and free to the Cuban public since 2011. New York Governor Andrew Cuomo’s trade mission to Cuba in April 2015 resulted in a signed agreement to bring CimaVax to the U.S., but as with all international drugs and treatments, U.S. researchers need to conduct clinical trials and replicate international scientists’ results before it becomes available to the American public.

"We’re still at the very early stages of assessing the promise of this vaccine, but the evidence so far from clinical trials in Cuba and Europe has been striking," said Dr. Kelvin Lee, Jacobs Family Chair in Immunology and co-leader of the Tumor Immunology and Immunotherapy Program at Roswell Park Cancer Institute in Buffalo, New York, the research center that is evaluating CimaVax for U.S. use.

The hoped-for success of CimaVax availability in the U.S. is just one example of the possibilities that come with open trade between the two nations. When Obama loosened the United State's 55-year trade embargo against Cuba in December, he allowed for such joint research deals to be finalized. Similar programs might have been impossible just a few years ago.

"You never know how long these things would take," said Candace Johnson, CEO of Roswell Park. "We would have loved to have had this already started because we’ve been working on this for quite a while, but we’re persistent and we’ll get it done."

Cuba has long been known for its high-quality cigars, and lung cancer is a major public health problem and the fourth-leading cause of death in the country. A 2007 study of patients with stages IIIB and IV lung cancer, published in the Journal of Clinical Oncology, confirmed the safety of the CimaVax and showed an increase in tumor-reducing antibody production in more than half of cases. It proved particularly effective for increased survival if the study participant was younger than 60.

So far, 5,000 patients worldwide have been treated with CimaVax, including 1,000 patients in Cuba. Lee said the latest Cuban study of 405 patients, which has not yet been published, confirms earlier findings about the safety and efficacy of the vaccine. What's more, the shot is cheap -- each costs the Cuban government just $1, Wired reported. Studies have found there are no significant 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," Lee said. "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."

How it works

CimaVax induces people to build antibodies against a certain growth factor that cancer cells make. 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 -- say, a lung cancer patient in remission -- the treatment acts as a vaccine to prevent future relapse. Johnson envisions that it could one day be a standard preventive vaccine that a person gets in childhood, much like the way we get vaccinated against polio, measles, mumps and rubella.

In addition to CimaVax, Roswell Park scientists are also reviewing other vaccine approaches from researchers at Cuba’s Center of Molecular Immunology (where CimaVax was invented) that could one day help patients overcome brain and pancreas cancer, as well as blood cancers like leukemia and lymphoma. While they aren’t as far along as CimaVax, Johnson said she is excited for the possibility these other treatments hold.

"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,” she said. "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."

To be clear, the CimaVax doesn't cure cancer. It's a therapeutic vaccine that works by targeting the tumor itself, specifically going after the proteins that allow a tumor to keep growing. (And as PBS points out, a person can't just take a shot of CimaVax and continue to smoke without fear of lung cancer.)

"We hope to determine in the next few years whether giving CimaVax to patients who’ve had a lung cancer removed, or maybe even to people at high risk of developing lung or head-and-neck cancers because of a history of heavy smoking, may be beneficial and may spare those people from having a cancer diagnosis or recurrence," Lee said.

What needs to happen first

Roswell Park faces many bureaucratic hurdles before clinical trials for CimaVax actually begin.

Because an embargo on Cuba is still in effect, Roswell Park had to apply for a license from the Office of Foreign Assets Control at the Treasury Department to bring CimaVax into the U.S. The license allows them to use it for lab research, but not to give it out to patients, Johnson explained.

Then, in order to start testing CimaVax on Americans, Roswell Park has to get approval for a trial from the U.S. Food and Drug Administration. Currently, Roswell Park and the FDA are communicating about the design of the trial, Johnson said.

Once the FDA signs off, Johnson has to submit the project to Roswell Park's Scientific Review Committee to evaluate its scientific merit, as well as their Institutional Review Board, a body that evaluates the ethical aspects of any medical research involving human subjects. These two final processes alone can take months to complete, Johnson said, and she hopes to start on Phase 1 and II clinical trials, which assess the effectiveness and safety of a drug, sometime in 2016. The entire process, from start to finish, can take years to complete -- even when the experimental drug was invented in the U.S.

To that end, the United States is currently at work developing two lung cancer vaccines of its own, GVAX and BLP 25, though neither has been studied for as long as CimaVax.

Cuba's public health record

How does a tiny island nation with limited economic resources pioneer a powerhouse cancer vaccine? “They’ve had to do more with less,” Johnson told Wired in May. "So they’ve had to be even more innovative with how they approach things. For over 40 years, they have had a preeminent immunology community.”

Despite decades of economic problems and the U.S. trade embargo, Cuba has been a model of public health. According the New York Times, life expectancy for Cubans is 79 years, on par with the United States, despite the fact that its economy per person is eight times smaller. While many drugs and even anesthesia have been hard to come by over the years, Cuba has one of the best doctor to patient ratios in the world. Moreover, the Cuban government's investment in primary care for residents and preventative health measures like public education, housing and nutrition have paid huge dividends in the health of citizens, especially relative to similarly poor countries.

Looking forward, ongoing research collaborations between the two nations are almost certainly on the horizon as relations between Cuba and the U.S. continue to thaw. For now, Lee says the researchers at Roswell Park have their eyes trained on about 20 cancer treatment and prevention technologies in Cuba -- including another lung cancer vaccine called racotumomab that the group hopes to study in clinical trials at Roswell.