Treatment of cancer beyond the local modalities of surgery and radiation
therapy is referred to as systemic therapy. This is the form of therapy
most important in reducing mortality since it is the growth and spread
of cancer away from its origin that is most likely to cause death. Systemic
therapy includes hormonal, biologic, targeted and chemotherapeutic agents.
I would like to discuss the ongoing development of two chemotherapy drugs
and how they are being used today as an example of drug development progress.
This is only one front in the war on cancer, but chemotherapy is currently
the most commonly used and important systemic therapy.
The drugs I want to discuss are Alimta and Cabazitaxel. Both are members
of new generations of a drug group which has been used for years. Alimta
is an antifolate, the first of which used in clinical oncology was Methotrexate.
Cabazitaxel is a member of the taxane group of which there are now four
members. The first drug used from this group was Taxol. Once oncology
researchers identify an effective drug, the mechanism of action of the
drug and its class is determined. Research efforts then shift to finding
related agents with improved efficacy and less toxicity.
Methotrexate was one of the first chemotherapy drugs identified and has
been used to treat Leukemia, Lymphoma, Breast Cancer and some other solid
tumors. It now has a small role in clinical oncology. Researchers identified
a compound that acted as an anti-folate at multiple sites on the target
enzyme. It was originally named multi-targeted anti-folate or MTAF. MTAF
was shown to have activity in Mesothelioma and Non-Small Cell Lung Cancer.
The Cancer Center of Thibodaux Regional was a participant in the clinical
trial that led to the FDA approval of MTAF in Mesothelioma. The drug was
then given the name Alimta. It is now part of the treatment of choice
for advanced Mesothelioma. We commonly use Alimta in the management of
The taxanes (Taxol, Taxotere and Abraxene) came into use in the 1990’s
and are among the most commonly used chemotherapeutic agents in multiple
cancers. The drug group has been heavily studied and multiple agents have
been developed. Cabazitaxel was developed and studied in advanced refractory
Prostate Cancer. It showed good activity and tolerance in clinical trials
and was recently approved. One of my patients who had failed Taxotere,
Mitoxantrone and several other drugs was told by his M.D. Anderson Oncologist
to come home and enter hospice. Though elderly and fragile, I offered
the patient a therapeutic trial of Cabazitaxel and he agreed. He has now
had 6 cycles with excellent tolerance and a dramatic response based on
his PSA level. Though not a cure, this new agent is helping this patient
live longer and with more quality of life with his disease.
These two drugs are effective agents developed based on knowledge of the
mechanism of older drugs. This new generation of drugs is made possible
by pharmacologic and clinical research. The Cancer Center of Thibodaux
Regional has participated in some of this research and is ready to utilize
these leading edge drugs as soon as they are commercially available. In
this way we continue to deliver the finest cancer care possible to our patients.