If diagnosed in its later stages, such as stage III, lung cancer will often have a poor prognosis. Half of these patients survive for one year,1 but only 5 of 100 patients survive for 5 years.2 In an effort to improve these grim statistics, experts are working tirelessly to uncover the next best treatment or cure. However, is it possible that they could stumble upon a lung cancer vaccine that could prevent the disease entirely?
Dr. Kananathan, a physician whose current interest lies in vaccine and cell therapy and who has participated in roughly 30 phase I, II, and III clinical trials, had a patient with stage III lung cancer. This patient had received standard chemotherapy and later decided to participate in a phase III clinical trial of a cancer vaccine in Cuba, called Cimavax.
According to Dr. Kananathan, “[Her] survival—48 months since diagnosis—has been remarkable.” 3 After the last visit, Dr. Kananathan wrote, “[She] was well and enjoying health.” 3
What is Cimavax?
Cimavax is a vaccine that is being developed to treat patients with tumors that grow faster due to a hormone called epidermal growth factor (EGF). This hormone encourages cell growth, including that of cancer cells and helps them spread. Most of these tumors express abnormally high levels of the receptor for EGF (called EGFR) or have mutated EGFR.4 About four to nine of every ten non-small cell lung cancers have high numbers of the EGFR.4 Tumors with high numbers of receptors for EGF grow well with normal EGF levels, but poorly with low EGF levels.
The vaccine, which is classified as therapeutic rather than preventative, works by targeting a specific protein in the bloodstream that tumors produce. When the proteins are attacked, antibodies are naturally released that fight against the EGF hormone. So, Cimavax targets specific antibodies to keep tumors from growing, meaning even late-stage cancer could benefit from it. However, researchers at the Roswell Park Cancer Institute are exploring ways to make Cimavax a preventative vaccine.
In the clinical trials, the Cimavax-treated lung cancer patients who were younger than 60 years of age survived an average of 18.5 months. These younger and vaccinated patients survived significantly longer than controls, who survived an average of 7.6 months.
What are the risks?
In the body, epidermal growth factors spur the growth of cells, including skin cells, and play a role in wound healing Because of this, there has been concern that Cimavax could reduce wound healing in most patients.
To answer this question, Fernandez Lorente examined the medical records of 452 Cimavax vaccinated patients for surgical wounds and healing. Out of the 452 patients, six had undergone surgery. The wounds of the six patients had healed normally—no infection, no excess bleeding, and no abscess.5
Mesothelioma and EGF
Is it possible, then, that mesothelioma patients could benefit from this vaccine? Unfortunately, not for most.
Twelve percent of pleural mesotheliomas contained mutations in the signaling pathways of EGF-EGFR.6 However, the mesotheliomas did not contain mutations in the EGFR or EGF genes themselves. 6,7 So, only if a mesothelioma patient has a mutation in the EGF or EGFR gene could Cimavax possibly be beneficial.
Thus, mesothelioma patients may be more likely to gain benefit from other options, such as a different immunotherapy, like checkpoint inhibitor, or a different vaccine in development with an estimated 90% response rate.
Tips
If considering a clinical trial, be sure to ask your physician whether your tumor is likely to be sensitive to the vaccine. Request information about the risks and side effects, then discuss the possible risks and benefits with your family and healthcare providers for your specific situation before deciding to enroll. From