Page 109 - Bio Engineering Approaches to Cancer Diagnosis and Treatment

4.7 Nonspecific immunotherapy 107

immune system in a nonspecific way. But unlike cytokines, these are not naturally
found in the body [111].
ICIs are proteins that block the cancer cells and stop the immune system of
destroying normal cells. PD-1, PD-L1, and CTLA-4 are molecules that are targeted
by ICIs [112].
After the approval of ipilimumab (anti-CTLA4) for the treatment of metastatic
melanoma in 2011, five other immune checkpoints inhibitor got approval as an anti-
PD-1 and PDL-1. The main function of these drugs is to remove inhibitory signals
of T cells activation. But still, some point of their operation needs to be understood.
One of this point is the expression of transforming growth factorβ (TGFβ) in can-
cers [113]. This factor drives immune dysfunction in the tumor because of inhibiting
CD8+ and Th1. Ravi et al. have invented a biofunctional antibody-ligand trap which
inhibits the expression of TGFβ and seeks to counteract T cells. Their preclinical
reg
research has shown a positive result as compared to the usage of checkpoint inhibitor
alone [114].
There are some other drugs such as Thalidomide, Lenalidomide, and Pomalido-
mide that are used in a nonspecific way. These drugs can cause some side effects
including drowsiness, fatigue, and low blood cell counts.
Immunotherapy has been widely interested in recent years and researchers have
found that using the body’s immune system and stimulating it against disease is
perhaps the best and only way to treat certain diseases such as cancer. In this regard,
there are a variety of methods which have been tested in laboratories and in clini-
cal experiences. On the other hand, eliminating cancer cells without damaging the
normal cells and normal tissues of the patients in hematological malignancies or
solid tumors has always been a wish for researchers. In this regard the advent of
methods such as antibody based targeted therapy, scientists are getting closer to
their dreams. However, traditional methods such as chemotherapy and radiother-
apy that have been used to treat cancer in the past are still used in combination
with immunotherapy, considering the benefits hereof and the positive effects it has
had over the years on destroying cancer cells. But with all the benefits of chemo
immune therapy and RIT, their effectiveness has been proven for the treatment of
some cancers, and researchers are more concerned with methods such as cancer
vaccination which extremely growing in the past decades. This method seems to be
highly potent in cancer stem cell apoptosis. Furthermore, scientists have focused on
personalized therapy which would be highly effective but with low publicity and
globalization. Finally, ADC is expanding to new stages and site selective and mul-
tiepitope ADCs would boost the result and globalization. Hence, it is worth noting
that although all of the discussed strategies have opened novel windows in cancer
treatment, there exist tremendous obstacles forward, so combination therapy is still
seeming to be the best approach.
In the following chapter another important cancer treatment method, cell therapy,
will be discussed.