The lung cancer vaccine from Cuba that Roswell Park Cancer Institute wants to study in the United States offers intriguing hope in extending the life of patients.
A small trial of the vaccine in Cuba for patients who failed chemotherapy and radiation found that it significantly increased life expectancy, and larger studies are underway in Cuba and other countries. The vaccine also appears to have few side effects and is inexpensive to produce.
But any optimistic expectations must be put into perspective.
The potential improvement in survival in late-stage cancer patients is a matter of months. And, like other lung cancer vaccines in clinical trials, it will have to prove itself effective in larger studies in this country, a process that will take years.
“This is an interesting vaccine because of its novel approach. And, because it has such mild side effects, the possibility of using it for prevention is exciting,” said Dr. Kelvin Lee, chairman of the cancer center’s department of immunology.
Roswell Park struck a deal with the Center for Molecular Immunology in Cuba to bring into the U.S. for study two vaccines developed at the Cuban organization – CIMAvax and racotumomab. The announcement came Tuesday at the conclusion of a two-day state foreign trade mission to Havana. The delegation with Gov. Andrew M. Cuomo included Lee; Candace Johnson, Roswell Park’s chief executive officer; and Howard Zemsky, president and chief executive officer of Empire State Development Corp.
The Buffalo cancer center has had informal exchanges with students and scientists in Cuba since 2011, but this is the first formal scientific relationship.
Johnson described CIMAvax as a vaccine with an “ingenious design” that arose out of necessity in Cuba as a result of meager research budgets. Roswell Park, as part of the agreement with the Center for Molecular Immunology, will prepare and file an investigational new drug application with the Food and Drug Administration to gain approval for testing of CIMAvax in the U.S.
CIMAvax is different from other lung cancer vaccines in development. Rather than targeting cancer cells, it works by targeting epidermal growth factor, a protein found naturally in the body that signals cells to grow. The vaccine works by stimulating the immune system, leading the body to produce antibodies that stop epidermal growth factor from attaching to cancer cells and signalling them to grow out of control.
“You wouldn’t think something like this would work,” Lee said. “The thinking is that you can’t get an immune response from a protein your body produces.”
Cuban researchers designed the vaccine for non-small cell lung cancer, the most common type. But the concept is applicable to other cancers, such as prostate, breast and colon.
Lung cancer accounts for about 27 percent of all cancer deaths in the U.S. and is by far the leading cause of cancer death among both men and women, according to the American Cancer Society. It’s estimated that 158,040 Americans will die this year from the disease. That’s more than all the deaths from colon, breast, and prostate cancers combined.
CIMAvax does not shrink tumors, Lee said. The promise is that it can stop cancer cells from growing by depriving a tumor of an important growth factor, thereby delaying the spread of cancer cells.
In a small trial of about 80 patients in Cuba, late-stage patients on the vaccine lived on average 12.7 months compared to 8.5 months for those who received supportive care. Lee said a larger Phase III trial with 400 patients in other countries is showing a longer life expectancy, as well.
Although the improvement seems modest, it would constitute progress in lung cancer treatment.
The overall five-year survival rate for lung cancer is 17 percent, and much lower once it has spread to surrounding tissue and other parts of the body. The disease is often diagnosed at a late stage.
The immune system is the body’s built-in defense against an array of disease-causing invaders, such as viruses and bacteria. Vaccines teach the immune system to fight disease by acting like a real infection. The idea of using the immune system to attack cancer is not new, and a number of different approaches have been tried without success.
However, growing knowledge about the body’s immune response continues to fuel excitement about the opportunity of designing a vaccine that could be used to treat lung cancer in combination with chemotherapy and, perhaps, prevent it in some cases. There are a number of potential cancer vaccines under study around the world, including the Center for Molecular Immunology’s second lung cancer vaccine, racotumomab.
In a 2011 paper in the Journal of Immune Based Therapies and Vaccines, Pedro Rodriguez and colleagues at the Cuban research organization wrote that more definitive research results for CIMAvax are needed, but that evidence is “consolidating” for a medical benefit.
Most new cancer vaccines are tested in patients with advanced disease after they have received other types of treatment. A potential benefit of CIMAvax, as well as other vaccines in development, is the possible use to prevent cancer in early stage cancer patients who have surgery to remove a tumor and then receive the vaccine to prevent a second occurrence.
Another futuristic possibility, because of the vaccine’s apparent safety and ease of administration through injection, is as a preventive measure in older smokers considered at high risk of cancer. Medicare this year began covering lung cancer screening in certain patients.
The Cuban research group released documents about how the vaccine is produced that Roswell Park will use in its application to the FDA. Officials expressed confidence that Roswell Park may be ready to start a trial of CIMAvax in eight months, if the approval process proceeds without major complications.
But questions remain. It’s unclear whether and how the federal government will inspect the manufacturing plant where CIMAvax is produced, Lee said.
The trade mission followed President Obama’s moves to normalize relations with Cuba. New York is the first state to send a group to the country in hopes of forging business ties.
Zemsky of Empire State Development, New York government’s economic development arm, noted that the vast majority of business opportunities today are occurring outside the U.S., and it makes sense for the state to develop a relationship with an emerging market for U.S. products and services that, until now, has been closed.
“It’s a great opportunity for the state,” he said, adding that the trade mission was well-received.
“It meant a lot to the people we met in Cuba,” he said.