4-03-06, 9:44 am
CUBAN scientists, whose field studies of therapeutic vaccines for the treatment of cancer have demonstrated encouraging results, have begun to work toward applying these therapies in the early stages of the disease.
The therapeutic cancer vaccines, produced from component elements of tumors, are not intended to cure patients but to keep the tumor under control for a long period. The drug attempts to stimulate and “teach” the immune system of the affected organism to detect and destroy malignant cells without the disagreeable side effects caused by chemotherapy and radio therapy.
In an article published on March 23 in Granma daily Dr. Luis Enríquez Fernández, head of the vaccine department of the Molecular Immunology Center (CIM) stated that, on the basis of animal experiments, Cuban and other researchers, can predict the value of transferring studies of these new cancer vaccine therapies to patients in the early stages of the disease in whom, theoretically, it would be possible to halt tumor growth for prolonged periods.
“Today, the specialized scientific community has sufficient evidence to begin firmly believing in this possibility and we have already begun working to eradicate this scourge on humanity via a preventative vaccine,” the doctor affirmed.
According to Enríquez Fernández, after nearly 30 years of clinical evaluations of the concept of therapeutic cancer vaccines and with more than 400 clinical trials completed, during which revolutionary advances in immunological thinking have occurred, “we have begun to understand the reasons for which the results obtained so far, although very encouraging, are modest in relation to patient benefits.”
For Fernández the problem is that the majority of these tests have been made on individuals in very advanced stages of the disease, in which the large tumorous mass and accumulated treatments received have profoundly deteriorated immune system functions.
The scientist believes that, in the case of cancer vaccines, the time to test and understand the concept better begins and ends in converting early stage tumors into chronic controlled illnesses, thus extending quality life for the patient.
He also noted that even though there still is no cancer vaccine being distributed for use by oncologists in the world, approximately 105 vaccine candidates exist in different phases of clinical trials, belonging to 64 companies (principally biotechnological) in five countries: the United States, the United Kingdom, Germany, Canada and France.
In Cuba, cancer vaccine field studies began at CIM in 1990. for the first time, that research was accompanied by an innovative cancer research program in an underdeveloped country.
Fernández recalled that after 15 years of labor, the program bore fruit: four original candidates for therapeutic cancer vaccines are being tested on patients throughout the country with the participation of Public Health Ministry specialized services.
“Just last year more than 170 new cases were incorporated into these trials, where the vaccines can prove their efficiency in the types of cancer that most impact the Cuban population: lung, prostate, breast and colon. “
The specialist, who acknowledges that the results obtained are encouraging and recommends the continuation of the studies, announced that two new vaccine candidates for the treatment of cervical and prostate tumors, developed by the Genetics Engineering and Biotechnology Centers (CIGB) in the capital and in the central province of Camagüey, are to enter the clinical trial phase this year.
In the modern laboratories of CIM, part of the West Havana Scientific Complex, 22 products are currently being investigated, which include, in addition to cancer vaccines, monoclonal antibodies such as CIMAher, registered since 2002 and holding a patent in 17 nations, which has shown promising results in head and neck tumors in combination with radiotherapy.
In the case of the therapeutic vaccine against lung cancer, based on the Epidermal Growth Factor (EFG) —a protein closely connected to cellular growth— Granma International reported in 2004 that it is to go through clinical trials in the United States for its later registration there this year, according to José Miyar Barruecos, secretary of the Council of State.
Said vaccine was subjected to clinical trials in Cuba with evident advantages in patient survival.
In a visit to various institutions of the Scientific Complex, two years ago, this weekly learned of the completion of a new pilot plant in the CIGB whose mission would precisely be to make batches of the EGF vaccine for clinical trials.
On July 15, 2004, CIM and the U.S. CancerVax Corporation of California signed a biotechnology technology transfer agreement in Havana in the presence of President Fidel Castro – the first in more than 40 years – for the cooperative production of anti-cancer vaccines. In the United States lung cancer causes more than a half a million deaths per year.
In a video sent to the participants in the signing of the agreement, Dr. Donald Morton, director and chief surgeon at the John Wayne Cancer Institute of Los Angeles, described the Cuban anti-cancer vaccines designed to stimulate the immune system as a unique discovery without precedent.
On this occasion, CIM director Dr. Agustín Lage emphasized the fact that no tradition exists of technology transfer, especially in biotechnology, from the South to the North.
In 2005, in a scientific conference in Havana, Dr. Carlos Borroto, deputy director of CIGB, recalled that during the 1980’s the island only possessed three biotech products, but at the close of the first five years of the 21st century this number has risen to 38. Moreover, the country exports $300 million worth of medicines annually to 51 countries.
From Granma
