While chemotherapy, radiation and surgery are well known cancer treatment methods, few people untouched by the malignant disease are aware of a new class of medication called targeted therapy drugs which are leading the way in a new, effective strategy in the war on cancer. Targeted therapy drugs are available for many different types of cancer but in the fight against leukemia, where surgery to remove a tumor is not an option, they are most welcome and improving survival rates.
Targeted therapy is a broad-based term used to describe a new class of drugs that seek to stop or inhibit the growth (dividing process) of new cancer cells by interfering with specific molecules that "signal" for new cancer cells to grow and develop. Since targeted therapy drugs are directed only at the molecules that "allow" the process of creating cancer cells, they generally do not harm healthy cells in the way that chemotherapy and radiation does, and is generally considered less harmful with side-effects than chemotherapy and radiation. Other names used to describe this class of drugs includes molecularly targeted drugs, and moleculary targeted therapies.
Targeted therapy drugs are used alone or in combination with chemotherapy drugs to maximize results. They are also divided up between first-line and second-line treatment consideration. First line treatment for cancer means that specific drugs, or a combination of drugs, is used in the initial round or course of treatment, before any other drug or combination of drugs is tried. Second-line treatment means that a specific drug, or combination of drugs, is used after first-round treatment was tried and failed, yielded poor results, produced side-effects considered too severe, and when a cancer has reappeared after remission.
Optimism over this new line of cancer drugs should be curbed since not all "targeted therapy drugs" turn out to be beneficial. Gemtuzumab ozogamicin (Mylortag®) was pulled from pharmacy shelves in the summer of 2010 by Pfizer after a closer look by the FDA revealed the drug offered no benefit when used with chemotherapy drugs, and after a greater number of deaths occurred in the group of patients who received Mylotarg compared with those receiving chemotherapy alone.
FIRST-LINE treatment targeted therapy drugs for leukemia include.
Imatinib (Gleevec®) is used to treat:
Philadelphia chromosome positive chronic myelogenous leukemia (CML).Hypereosinophilic syndrome or chronic eosinophilic leukemia (CEL).Relapsed or refractory Philadelphia chromosome positive acute lymphoblastic leukemia (ALL).With this drug, more than 90% of patients will be able to keep CML in check for at least five years, reducing it to a chronic, manageable condition in that time. Gleevec is considered to be one of the most successful examples of targeted therapy, available today. It works by blocking the action of the abnormal protein that signals cancer cells to multiply. Gleevec, approved in 2001, was one of the first targeted therapy drugs to come out and is one of the most widely used since it is also used to treat gastrointestinal stromal tumors (GISTS). Ninety percent of all chronic myelogenous leukemia cases involving the Philadelphia chromosome.
Nilotinib (Tasigna®) is used as a first line treatment to treat chronic myelogenous leukemia (CML) that is Philadelphia chromosome positive. Early results of an on-going 5 year study revealed in December, 2010, show that Tasigna might be superior to the popular Gleevec for treating CML patients. Tasigna cut the amount of a tell-tale protein in the blood in three times as many patients with leukemia as did it's predecessor, Gleevec.
In a Bloomberg story stemming from press release issued by the drug's maker, the company reported: "In the clinical trial, designed to follow about 900 patients for five years, almost three times more people taking 300 milligrams of Tasigna twice daily had only a trace amount of the Bcr-Abl protein in their blood after 24 months. The other patients took either 400 milligrams of Gleevec once a day or 400 milligrams of Tasigna twice a day."
Tasigna is mabe by Novartis, the same company that created Gleevec. Novartis considers Tasigna the superior successor to Gleevec, whose patent runs out in 2015. The down-side of Tasigna is that it carries a black box warning from the FDA for an irregular heart rhythm (QT prolongation) that can lead to fainting, loss of consciousness, seizures, or sudden death. Even with this warning, the FDA granted Tasigna first-line treatment status for Philadelphia chromosome-positive chronic myeloid leukemia in the chronic phase in June, 2010.
Dasatinib (Sprycel®) was once the go to drug when Gleevec and other types of medications don't work initially, no longer work, or are not administered due to their severe side-effects, but is now a first-line treatment drug for CML. Sprycel is used to treat:
Chronic myelogenous leukemia (CML). This includes patients with CML that is Philadelphia chromosome positive. (Approved first-line treatment).Acute lymphoblastic leukemia (ALL) that is Philadelphia chromosome positive, in patients who are not able to use other drugs including Gleevec. (Second-line treatment).Sprycel works the same way as Gleevec, by blocking the action of an abnormal protein that tells cancer cells to multiply. Sprycel received first-line treatment status for CML-Philadelphia chromosome by the FDA in October, 2010.
SECOND-LINE treatment targeted therapy drugs for leukemia include:
Tretinoin (Vesanoid®) is used to treat acute promyelocytic leukemia in patients who did not benefit from other types of chemotherapy, or whose condition improved with other types of chemotherapy, but then got worse. Tretinoin is used to produce remission (a decrease or disappearance leukemia symptoms ) in APL, however, other medications must be used after treatment with tretinoin to prevent the cancer from returning. Vesanoid comes with an FDA warning for a group of symptoms related to its main ingredient which is a type of Vitamin A.
Rituximab (Rituxan®) is used in combination with other drugs (primarily the chemo drug fludarabine) to treat B-cell chronic lymphocytic leukemia, including hairy cell leukemia (a subtype of CLL). Rituxan comes with an FDA warning that oncologists make aware to their patients.
Alemtuzumab (Campath®) is used to treat B-cell chronic lymphocytic leukemia (B-CLL) after a chemotherapy drug called fludarabine has failed. Campath comes with an FDA warning that patients will be informed about.
Ofatumumab (Arzerra®) is approved by the Food and Drug Administration (FDA) to treat chronic lymphocytic leukemia (CLL) in adults that have not gotten better with a chemotherapy/targeted drug therapy involving fludarabine (chemo), and alemtuzumab (targeted).
Jason L Morrow is the founder and editor of OmniMedicalSearch.com. where you can learn more about leukemia symptoms.
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