This interesting (and sad) letter in the New England Journal of Medicine highlights the shortage of chemotherapy treatments for children suffering from leukemia:
"There was a significant inverse relationship between the amount of prescribed chemotherapy that was administered and the risk of relapse."
The study reinforced the notion that the most important factor in improving survival, even in children with leukemia, is adequate treatment.
Showing posts with label Hematology. Show all posts
Showing posts with label Hematology. Show all posts
Friday, July 25, 2008
Monday, May 12, 2008
Knocking out cancer cells in Leukemia
Cancer initiating cells (CICs) or leukemia initiating cells (LICs) are stealth populations impervious to conventional chemotherapy and resistant to targeted cancer therapies. When a leukemia patient relapses following a period of remission, it is the LICs that are the cause of the disease’s re-emergence.
Researchers at the Beth Israel Deaconess Medical Center (BIDMC) have found that a tumour suppressor protein known as PML appears to be the factor that enables LICs to maintain their quiescence, the inert state that protects them from being destroyed by cancer therapies. They suggest that inhibition of PML is a promising target for new agents.
Their findings, which appear in Nature, also demonstrate that PML can be degraded with an arsenic-based agent called arsenic trioxide, which has been used in traditional Chinese medicine. When combined with chemotherapy, the arsenic-based therapy, already proven safe and non-toxic in clinical trials for a rare form of leukemia called Acute Promyelocytic Leukemia (APL) can also potentially treat the more common Chronic Myeloid Leukemia (CML) and reduce risk of relapse.
The concept is a very simple one; 90% of existing cancer treatments are anti-proliferative agents. They target the pool of proliferative cells, leaving behind the dormant LICs. By knocking out the quiescent cells with arsenic trioxide, the risk of relapse is much reduced. This approach might be useful in other treatment approaches for different leukemias.
Researchers at the Beth Israel Deaconess Medical Center (BIDMC) have found that a tumour suppressor protein known as PML appears to be the factor that enables LICs to maintain their quiescence, the inert state that protects them from being destroyed by cancer therapies. They suggest that inhibition of PML is a promising target for new agents.
Their findings, which appear in Nature, also demonstrate that PML can be degraded with an arsenic-based agent called arsenic trioxide, which has been used in traditional Chinese medicine. When combined with chemotherapy, the arsenic-based therapy, already proven safe and non-toxic in clinical trials for a rare form of leukemia called Acute Promyelocytic Leukemia (APL) can also potentially treat the more common Chronic Myeloid Leukemia (CML) and reduce risk of relapse.
The concept is a very simple one; 90% of existing cancer treatments are anti-proliferative agents. They target the pool of proliferative cells, leaving behind the dormant LICs. By knocking out the quiescent cells with arsenic trioxide, the risk of relapse is much reduced. This approach might be useful in other treatment approaches for different leukemias.
Wednesday, April 30, 2008
Hematology - heparin contaminant may have been deliberate
A US Congressional hearing was held on Tuesday to discuss the recent heparin contamination issue. The hearing was dubbed, "The Heparin Disaster: Chinese Counterfeits and American Failures".
Baxter, which supplied half of the US market, issued a voluntary recall of the drug in January 2008 and again in February after multiple patients starting experiencing severe side effects like abdominal pain, decreased blood pressure, burning sensation, chest pain, diarrhea, dizziness, loss of consciousness and vomiting. The drug eventually caused more than 80 deaths.
The company denied that it was responsible for contaminated batches of Heparin, an anticoagulant used mostly in hospitals, and that it may have been a deliberate contamination. It's CEO, Robert Parkinson, said that, CEO Parkinson said, "We're alarmed that one of our products was used, in what appears to have been a deliberate scheme, to adulterate a life-saving medication, and that people have suffered as a result".
The contaminant was an altered form of chondroitin sulfate, a drug that mimics the affects of Heparin. The company said during the hearing that the drug was in the batches before it reached Baxter's supplier, Scientific Protein Laboratories. Several other companies in multiple other countries found traces of the contaminant in their supplies of Heparin, as well. Parkinson testified that the company is still trying to understand where in the supply chain the contaminant was introduced, but the company believes it was in the raw material.
Heparin is one of several products coming out of China that have been recalled because of problems with production. Last year, there were recalls concerning toys and toothpaste made in China. The Chinese government has maintained that the contaminated Heparin was not associated with the adverse affects and deaths. This theory was debunked by Kishimoto et al., who provided a scientific rationale for a potential biologic link between the presence of over-sulphated condroitin in suspect lots of heparin and the observed clinical adverse events. They reported their findings in the NEJM earlier this year.
Heparin is a generic that has been around for more than 70 years. It is made from pig intestines. At the hearing, members of Congress discussed the rising cost of hogs as a potential reason for someone substituting the Heparin with the lower-cost chondroitin sulfate. The contaminant is an unnatural substance that was highly processed, pointing to the likelihood that the substance was deliberately added.
The committee appeared to be laying blame with the US FDA inspectors; the FDA only inspects foreign drug makers every 13 years. Baxter relied on inspections and audits of the SLP factory done by its predecessor, Wyeth, and did not conduct audits of the Chinese factory itself.
In short, it was a disaster waiting to happen; no one took responsibility or accountablity for the quality of either the raw materials or the final product, ultimately compromising patient safety.
Baxter, which supplied half of the US market, issued a voluntary recall of the drug in January 2008 and again in February after multiple patients starting experiencing severe side effects like abdominal pain, decreased blood pressure, burning sensation, chest pain, diarrhea, dizziness, loss of consciousness and vomiting. The drug eventually caused more than 80 deaths.
The company denied that it was responsible for contaminated batches of Heparin, an anticoagulant used mostly in hospitals, and that it may have been a deliberate contamination. It's CEO, Robert Parkinson, said that, CEO Parkinson said, "We're alarmed that one of our products was used, in what appears to have been a deliberate scheme, to adulterate a life-saving medication, and that people have suffered as a result".
The contaminant was an altered form of chondroitin sulfate, a drug that mimics the affects of Heparin. The company said during the hearing that the drug was in the batches before it reached Baxter's supplier, Scientific Protein Laboratories. Several other companies in multiple other countries found traces of the contaminant in their supplies of Heparin, as well. Parkinson testified that the company is still trying to understand where in the supply chain the contaminant was introduced, but the company believes it was in the raw material.
Heparin is one of several products coming out of China that have been recalled because of problems with production. Last year, there were recalls concerning toys and toothpaste made in China. The Chinese government has maintained that the contaminated Heparin was not associated with the adverse affects and deaths. This theory was debunked by Kishimoto et al., who provided a scientific rationale for a potential biologic link between the presence of over-sulphated condroitin in suspect lots of heparin and the observed clinical adverse events. They reported their findings in the NEJM earlier this year.
Heparin is a generic that has been around for more than 70 years. It is made from pig intestines. At the hearing, members of Congress discussed the rising cost of hogs as a potential reason for someone substituting the Heparin with the lower-cost chondroitin sulfate. The contaminant is an unnatural substance that was highly processed, pointing to the likelihood that the substance was deliberately added.
The committee appeared to be laying blame with the US FDA inspectors; the FDA only inspects foreign drug makers every 13 years. Baxter relied on inspections and audits of the SLP factory done by its predecessor, Wyeth, and did not conduct audits of the Chinese factory itself.
In short, it was a disaster waiting to happen; no one took responsibility or accountablity for the quality of either the raw materials or the final product, ultimately compromising patient safety.
Monday, April 28, 2008
Market intelligence - hematology insights
An artificial blood substitute that has a long shelf life and does not need refrigeration could save untold lives by providing an alternative to trauma patients in emergencies, especially in rural areas and in combat settings.
A new analysis reported in JAMA, however, concluded that the FDA approved experiments with artificial blood substitutes even after studies showed that the controversial products posed a clear risk of causing heart attacks and death.
The review of combined data from more than 3,711 patients who participated in 16 studies testing five different types of artificial blood, released today, found the products nearly tripled the risk for heart attacks and increased the chances of dying by 30 percent. Based on the findings, the researchers questioned why the FDA allowed additional testing of the products to go forward and why the agency is considering letting yet another study proceed.
An FDA official declared that the risks and benefits of each study had been carefully weighed and a two-day meeting had been convened this week to address the new concerns raised by the analysis.
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