CIMAvax is so interesting, scientifically speaking, because it belongs to a new class of cancer treatments called immunotherapy. Rather than using a scalpel, radiation, or chemicals to take cancerous cells out directly, immunotherapy stimulates the patient’s own immune system to fight cancer. A few immunotherapies are already on the market, and pharmaceutical companies are racing to develop the next. For the past two decades, Cuba, a country with a tiny biomedical research budget, has been quietly sitting on CIMAvax. And this vaccine could be just one of the first of several Cuban drugs, currently locked behind the embargo, to make to the U.S.
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The collaboration between Roswell and Cuba’s Center for Molecular Immunology, which developed the vaccine, actually began in 2011, years before the Obama administration started easing restrictions on Cuba. Gisela Gonzalez, one of the Cuban researchers working on CIMAvax, was visiting family in Pittsburgh when she cold-called one of Lee's colleagues at Roswell.*** She wanted to give a talk about the research they were doing in Cuba.
“We were not thinking about Cuba at all,” says Lee. “Our image of Cuba was from back in the I Love Lucy days. We didn’t consider they had really advanced cancer treatments.” But Cuba manages to punch far above its weight in medicine. Although the country lacks access to advanced medical equipment due to the embargo, life expectancy in Cuba is even a bit higher than in the U.S. Its strength is a robust primary-care system that focuses on disease prevention.
That’s how CIMAvax came along, too. In the 1980s, Cuba developed a vaccine to prevent meningitis, a bacterial infection of the membranes around the brain. The vaccine uses pieces of protein from meningitis bacteria, which signal “hey, I’m foreign” and switch the immune system into attack mode. One particular protein, they found, was especially good at activating the immune response.
So when researchers at the Center for Molecular Immunology turned their attention to lung cancer—then the number-two killer in Cuba—they didn’t start from scratch. They took that unusually powerful meningitis protein and fused it to part of another protein called epidermal growth factor, or EGF. EGF is important for controlling cancer because, as its name implies, EGF makes cells grow, and cancer is essentially cells growing out of control. When injected, this fused hybrid protein kicks a patient’s immune system into high gear (thanks to the meningitis) and targets cancer cells (thanks to the EGF). That’s how CIMAvax is supposed to work. It’s called a vaccine because like other vaccines, it stimulates the immune system, but it is actually used to treat rather than prevent lung cancer.
Lee recalls learning all this for the first time at Gonzalez’s talk. “I’m just sitting in the audience and going, ‘That’s really amazing,’” he says. CIMAvax had been approved in a handful of Latin American countries by then, and a handful of desperate American patients have since traveled abroad to get CIMAvax. The vaccine doesn’t necessarily kill cancer cells, but it slows their growth enough to prolong patients’ lives by several months in trials. And its side effects are mild, especially compared to how chemotherapy can ravage the body.