Clapper, Patti, Schweizer and Mason

Pemetrexed, as far as cancer treatment drugs go, is one of the more recent and exciting chemotherapy drugs on the market and has been used as a mesothelioma treatment with relative success.  While the drug doesn’t represent a cure, it is often more effective and less-harmful than several of the older more traditional drug therapy options.  However, the exact mechanism through which pemetrexed works and the internal factors that influence its effectiveness are still under examination. 

In one recent study, scientist searching for an effective external measure of how well pemetrexed treatment was working with individual patients discovered that levels of thymidylate synthase in the blood could be used as a sort of gauge.  That’s because pemetrexed works (partially) by inhibiting the production of certain chemical and biological component necessary for mesothelioma growth; thymidylate synthase (TS) being one of them.  TS is an enzyme essential for cell growth and repair.  It is used during DNA synthesis and repair and if levels are effectively lowered, mesothelioma cells are hampered during reproduction.  The cells eventually die and are not replaced.

During this study, scientist weren’t surprised to discover that the levels of TS directly correlated to the effectiveness of pemetrexed treatment but were excited that the relation was so causal in effect.  This revelation could indeed be used in future patients to gauge and predict how effective pemetrexed treatment will be.  This time-saving measure is essential in the fight against mesothelioma because this type of asbestos cancer is incredibly aggressive and most patients who are diagnosed with the disease are given just a few short months to live.

During the same study, doctors discovered that higher levels of folylpoly-y-glutamate synthetase (FPGS) actually corresponded to better results.  This is because this chemical compound actually converts the chemotherapy drug pemetrexed into a more effective form.  Therefore, patients with more FPGS to spare can readily convert pemetrexed in larger doses, thereby controlling the growth of malignancy much more effectively.  

While this research isn’t groundbreaking, any research that comes away with concrete results is essential.  Roughly 3000 people each year in the United States are diagnosed with mesothelioma, with most patients not surviving more than a year or two after diagnosis.  The key components of this essential research is understanding how current chemotherapy drugs work, what makes them more effective, and how to gauge which would be most effective for each individual patient.