Immune checkpoint therapy treats cancer by inhibiting negative immune regulation using antibodies against CTLA4 and PD antigens. CTLA4 acts as a negative immune regulator, and an anti-CTLA4 antibody called ipilimumab was developed in 1999 to treat metastatic melanoma in mice and humans. PD1 is expressed by macrophages, dendritic cells, and some tumor cells, and anti-PD1 antibodies like pembrolizumab and nivolumab were first approved by the FDA in 2014 to treat metastatic melanoma. Combining anti-CTLA4 and anti-PD1 antibodies seems to have an even stronger anti-tumor effect in melanoma and renal cell carcinoma.

1. IMMUNE CHECKPOINT THERAPY
PRESENTED BY: M.ARUMUGAVIGNESH R.VIGNESWARAN
ABSTRACT:
Immune checkpoint therapy is the treatment of cancer by inhibition
of negative immune regulation. CTLA4 and PD are the antigens which
act as inhibitors for T lymphocytes to act against tumor cells. By
introducing antibodies against CTLA4 and PD we can treat cancer. This
is the fourth new pillar in the treatment of cancer after surgery,
radiation therapy and chemotherapy. This concept has won the noble
prize for medicine in 2018.
ANTI CTLA4 ANTIBODY TO TREAT CANCER:
CTAL4 is an abbreviation for Cyto toxic T Lymphocyte Antigen 4. This
antigen acts as a negative immune regulator. An anti CTLA4 IgG1
monoclonal antibody named MDX 010 was developed in 1999, later
named ipilimumab. Metastatic melanoma in mice and humans can be
controlled by this drug.
PD 1 BLOCKADE AS A TREATMENT OF CANCER:
PD 1 is an acronym for Programmed cell Death antigen 1. This molecule
was discovered to be expressed by macrophages, dendritic cells and also by
some tumor cells. The PD 1 blockade antibodies were first approved by FDA
in 2014. Some examples for this agent are pembrolizumab and nivolumab.
At first these drugs were approved for the treatment of metastatic
melanoma. Later in 2015 ,the approval was expanded for the treatment of
metastatic squamous non- small cell lung cancer. The anti PD 1 antibodies
were the first class of agents granted approval by the FDA based on a
genetic characteristic of the cancer rather on the organ or histologic origin
of the disease in 2016.
COMBINATION THERAPY:
The combined therapy of both anti CTLA4 antibody and anti PD 1 antibody
has seemed to induce an even stronger anti tumor effect in both melanoma
and in renal cell carcinoma.
CONCLUSION:
This therapy is a new weapon against cancer. This provides a valuable
information about human immune response in tumor micro environment.