The American Society of Clinical Oncology (ASCO) meeting that took place this year was highlighted by a discussion of a new class of immuno-therapeutic drugs that may eventually represent a massive breakthrough in cancer research. Bristol-Meyers, Squibb, Merck & Co. and Roche introduced updated findings in reference to their PD-1 and PD-L1 inhibitors. It was seen that these drugs may work in more similar means than initially expected. In addition, the prospects for the usefulness of these drugs is surmised to be in melanoma treatments, although more commercial and wide-ranging applications are also thought to be possible.
PD-L1 is an acronym for a series of proteins that may help a cancer evade a host's immune system. It is thought that by selectively targeting these proteins, a cancer will be more easily recognised by an immune system; therefore allowing an organism to more effectively destroy the invading cancerous cells. This can be seen as a possible step towards the next generation of immunotherapies. Such success has already been seen in another inhibitor produced by Bristol-Meyers and Squibb's cytoxic T-lymphocyte antigen-4 (CTLA-4) inhibitor. The generic name for this treatment is known as Yervoy (ipilimumab).
It is particularly noted that high tumor expression of PD-L1 was directly correlated with more aggressive cancers. This suggests that if PD-L1 proteins could be suppressed by a counteractive inhibitor, the growth rates and aggressive natures of many types of cancers may be slowed significantly. This has obvious importance with more aggressive forms that have a poor prognosis for current treatments.
Another significant point of the relationship between PD-1 and PD-L1 is the fact that patients suffering from various autoimmune diseases such as Lupus presented altered levels of PD-L1 response. Thus, the inhibition of this protein through the use of PD-1 may also help combat degenerative autoimmune disorders.
As of yet, the role of PD-L1 is only beginning to be understood. Nonetheless, clinical trials of PD-L1 blockers has already begun as of April of 2013. It is hoped that through these trials, the exact function of PD-L1 can be further isolated and a new line of immuno-therapeutic drugs can be established that may present more efficacious treatment options in the near future. Companies such as Bristol-Meyers, Squibb, Merck & Co. and Roche are at the leading edge of much of this research. It is indeed true that the medical and scientific community will continue to watch the findings of these studies with great interest.