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Cuba working to use anti-cancer
therapies in early stages of disease
• Clinical trials to begin
this year on two new vaccine candidates for the
treatment of cervical and prostate tumors
BY LILLIAM RIERA
—Granma International staff writer—
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.
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