New Drug Has Potential To Destroy Leukemia

Essay, Research Paper

New Drug has Potential to Destroy Leukemia

White blood cells are the body’s foot soldiers in its everyday battle against infections and diseases. Even when we are feeling well, they are working together in a carefully orchestrated manner to target and destroy dangerous substances in our body. Any disease that prevents the white blood cells from doing their job puts us at great risk for infection and illness. Leukemia is that kind of disease. It happens when our body’s system for making white blood cells malfunctions, resulting in the uncontrolled production of abnormal white blood cells that cannot protect us against disease. If left untreated, leukemia can cause death in a matter of months. Simply put, leukemia is a cancer of the blood cells. It usually involves the white blood cells, but in rare cases involves the red blood cells and platelets as well. The disease originates in the bone marrow. Like all cancers, it is characterized by the uncontrolled growth of abnormal cells. When these defective cells accumulate in the bone marrow where they are produced, it inhibits the production of blood cells of every kind. All blood cells pass through many stages on their way to complete maturity, beginning within the bone marrow as immature cells called blasts. Leukemia can occur at any of these stages of development, affecting one of the two major categories of white blood cells: lymphoid cells or myeloid cells. According to J. Gordon McVie author of “Cancer Treatment: The Last 25 Years,” states that each year, nearly 27,000 adults and more than 2,000 children in the United States learn that they have leukemia. It affects 13.2 per 100,000 men and 7.7 per 100,000 women in the United States. Chronic leukemia comprises 35% to 50% of all cases of leukemia (324). With such a great number of people becoming infected with this rapidly spreading disease, medical science has worked almost endlessly to improve the outlook for leukemia patients. Chronic myeloid leukemia, or CML s probably the most well known and studied type of leukemia. According to the Leukemia Insights Newsletter CML is a cancer of the blood cells. Blood cells are produced in the bone marrow, the spongy interior of the bones. Normally, blood cells are made in an orderly, controlled way. When CML develops, the bone marrow produces large numbers of normal-appearing and normal-functioning blood cells. However, all the circulating blood cells arise from one abnormal cell and contain the Philadelphia chromosome that causes the disease. In the early stage of CML called chronic phase, the only possible complication of the disease is poor blood circulation because of too high blood cell counts. This complication can be completely prevented by controlling the blood counts with a variety of drugs (hydroxyurea, interferon, busulfan). Cure of CML is possible during chronic phase with bone marrow transplantation (BMT). This stage of CML lasts an average of 4-5 years, after which it advances to accelerated phase or blast crisis. This final phase of CML resembles an acute leukemia with increasing numbers of abnormal immature “blast” cells that crowd out the normal blood cells, and is very difficult to treat, however if treatment is admitted early, remission is possible (1,5). Especially with the great advances the medicine is making daily in cancer research.

Each leukemia is different, just as individual responses to treatment are different. The newest form of treatment recently released in the article “New Leukemia Drug Gives Patients Hope” in The Herald Leader is directed toward chronic myeloid leukemia, or CML. The drug STI-571 is an experimental pill that is still in its earliest form of testing. In a study which Dr. Brian J. Dunker of the region Health Sciences University discusses in this article he states that when 31 patients were given a minimum of 300 milligrams of STI-571 a day, the white and red blood cell counts sustained a normal count for eight months. The most crucial aspect of this study was the remarkable speed of the drug. About 30 patients who received treatment regained normal blood count within the first month of treatment (McConnaughey 1-2). Unlike traditional, toxic chemotherapy remedies, which kill both cancerous and healthy cells, STI-571 specifically targets an enzyme found only in leukemia cells, meaning patients suffer minimal side effects. An article recently published in The Lancet by Lalit Kumar and Subhash C. Gulati states that CML is known to scientists as the defect with the “Philadelphia chromosome.” The Philadelphia chromosome results when chromosomes 9 and 22 exchange genetic material. This translocation fuses two genes that shouldn’t be together. This fusion releases an enzyme that spurs lethal growth of white blood cells, usually beginning in adulthood. Kumar and Gulati state that STI-571 inhibits the activity of this enzyme, rapidly killing the leukemia cells. The drug only targets the cancer cells because only those cells contain the specific enzyme that STI-571 inhibits. Dr. Moshe Talpaz of the M.D. Anderson Cancer Center in Houston, Texas has some intense feelings about STI-571. “It’s fantastic! These people who have been treated with traditional methods and failed still have hope. Although their doctors said they didn’t have long to live, now most are feeling well with good blood-cell counts” (984-985). Author Bradley Somer states that current therapeutic options for CML include hydroxyurea, interferon alpha and allogeneic bone marrow transplant. The first of these two treatments only delay the diseases progression and the bone marrow transplants are merely used as an attempt to cure patients under the age of 50 (OncoLink). The Journal of American Medical Association states that standard theory has much more severe side effects then the new drug STI-571. Interferon alpha cause adverse symptoms such as lack of energy, fever, or other flue like symptoms. The only adverse effects on the experimental drug STI-571 include mile nausea when the daily intake was taken without food. Studies also showed that about 10% of patients suffered from minor muscle cramps. Author Stephenson states that using this drug in a combination with other antineoplastic agents may help prevent the emergence of resistance, which is more likely to occur when a single agent is used (318,321). One of the greatest testimonies that can be shown in favor of the new drug is from personal experiences. Leukemia patient Virginia Garner, who was dying from leukemia not long ago and did not respond to interferon, the most common form of treatment for CML, became extremely enthusiastic about the experimental drug. In an article published in Science News by N. Seppa Garner said, “It has no side effects whatsoever. It’s literally given me my life back.” (372). Another major testimony of the miraculous success of STI-571 was shown when pastor Ron Viettie became the first person every to receive the experimental drug. Vietti was diagnosed with chronic myelogenous leukemia in February 1997 and took his first dose of STI-571 in December of 1999. Vietti states that is drug will revolutionalize the medical treatment of cancer forever. “STI-571 will transform CML from a terminal disease to a manageable chronic disease, at worst.” Viettie began his fight against CML by trying hydroxyurea, interferon, and chemotherapy. Despite his willingness to fight this disease no form of treatment seemed to work. When Vietti took the first dose of STI-571 he began only with 25 milligrams due to the uncertainty of the drugs affects, however he was ecstatic that he had found another hope for survival. Not only has Vietti’s blood count sustained but the genetic indicators of leukemia also seem to be vanishing. Fewer chromosomes have tested positive for the Philadelphia chromosome that identifies those with CML (Terwilleger 1-3). These great testimonies show how affective STI-571 has already been and hopefully provides a great hope for the advancement of CML treatment.

The best way to assess the effect of cancer treatment over the last 25 years is to look at survival data. Whereas for some cancers earlier diagnosis, for instance, via a screening programme, could impact survival figures, development of successful systematic therapy and the improved outcomes for many common cancers can cause and effect. According to the article “One-Hundred Percent Success for Leukemia Drug” published on BBC News Online the current methods of cancer treatment has appeared to increase overall survival, however, these methods have not stop the growth of cancer. Between an average of five years the overall survival rate for men with chronic myeloid leukemia has increased about 10%, while women have increased about 13%. These statistics both show a great increase in the scientific success of cancer treatment however science has not stopped working to destroy this rapidly growing disease. BBC News states that the drug STI-571 could be the “cure” that scientists have been searching for. STI-571 is a drug that is still experimental however its support among pharmaceutical companies and the optimistic outlook created by scientists, doctors, and patients make many feel that STI-571 is the solution to CML (One-Hundred Percent 2). Author Seppa in Science News shows how individual doctors feel about STI-571. Dr. John Groffen, a molecular biologist at the Children’s Hospital and the University of Southern California, both in Los Angeles said “CML is one of the best-known types of cancer. It was inevitable that scientists discover a cure for total remission.” Groffen also states that the use of STI-571 seems to be very promising. “On the other hang, one has to be a little careful.” This leukemia has shown that even though it is the most known about that it also has a tendency to fluctuate. Shifts between remission to recurrence can occur completely unpredictably ( 372). Before becoming to optimistic about this new form of treatment it is impeccable that we realize that it is still in a new state. The long term affects are still questionable and remission is still impossible. However before excluding STI-571 it is important to evaluate if you are a good candidate for treatment and whether the risks are worth the hopes of complete remission.

Chronic myelogenous leukemia results from an acquired not inherited injury to the DNA stem cell in the marrow. Scientists do not yet understand what produces this change in the DNA of CML patients. Scientists do express that as the human genome unfolds, cancer-related genes with unquestionable be identified and then gene products will be developed, such as insulin for diabetes, for maintenance of steady state environment in cancer patients, while gene therapy in some form or other dedicated to switching off an oncogene or repairing a rumor suppressor will come of age. There is much to hope for in following years. The difference between the end of the millennium and the beginning of the last quarter is that eventually we will be able o refine tailor-made treatments designed to match an individual patient’s tumor.

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*http://oncolink.upenn.edu/disease/leukemia1/cml.html.*

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