The Promise of Immunotherapy
New biologics that harness the immune system against cancers (immunotherapy) are significantly altering care pathways in oncology and potentially other fields. The promise of immunotherapy lies in the hypothesis that one's own immune system could drive a better response with fewer side effects.
Programmed death 1 (PD-1) is a key immune receptor found on
activated T cells. Activation of this receptor suppresses the immune
response. Immunosuppressive PD-1 ligands (PD-L1), are expressed by
many tumor cells which suppress T-cell mediate immune response when
they interact with PD-1. The mechanism of action of this class of
therapies is based on inhibition of the interaction between PD-1 and
PD-L1. Inhibiting this interaction can enhance T-cell response to
the cancer.
Most development has been directed to the PD-1 receptor on the
T-cell but there are compounds coming through the pipeline which are
targeted at the PD-L1 on the tumor cell. Up coming data points will
do more to clarify the potential of anti-PD-L1 therapies.
In practice, immunotherapy has shown efficacy in select indications,
on small subgroups with considerable variability. Tolerability has
also been an issue, as in one of the first agents, interleukin-2.
However, immuno-oncology is one of sector’s most exciting pipeline
opportunities with potential in improving survival in melanoma, lung
and renal cell cancer with newer agents already demonstrating better
improving tolerability.
Bristol Myers Squibb is the most advanced and best positioned to benefit from its pipeline in this field, with Merck (MRK) also having a strong pipeline. Other large pharmaceutical companies with a significant immunotherapy pipeline include Roche, Galxo Smith Klein, Astra Zeneca and Amgen.
