Friday, December 28, 2012

Drug Shortage Linked To Cancer Relapse

A drug shortage appears to have caused a higher rate of relapse among children, teens and young adults with Hodgkin lymphoma, researchers form St. Jude Children's Research Hospital reported this week. The scientists say this is the first example of the tragic consequences of the current drug shortage. They emphasized that protecting patient access to lifesaving treatment must always be the number one priority in any health care system.
Children, adolescents, and young adults with Hodgkin lymphoma in a national clinical trial showed an estimated two-year cancer-free survival rate that dropped from 88 to 75 percent due to a drug shortage.

The study began before any reported drug shortages, however, the change started in 2009 after a shortage of mechlorethamine became apparent. The drug mechlorethamine was replaced by cyclophosphamide for treatment of patients with middle or high risk Hodgkin lymphoma.

No study patients are deceased, but those who relapsed had more rigorous therapy that was linked with higher risks of infertility and other health issues later.

The results of comparing these two groups two years after their cancer diagnoses are published in the New England Journal of Medicine. The outcomes demonstrate the first available evidence of a drug shortage that resulted in disadvantages in specific patients.

History Of Drug Shortages

Recently, many caregivers and patients have had their medical treatments compromised by drug shortages, like mechlorethamine and other injectable drugs. Available since the 1960's for cancer treatment, mechlorethamine just became obtainable again.

Cyclophosphamide is a safe and effective substitute for mechlorethamine, used for decades for treatment of children and adults with Hodgkin's lymphoma.

Monika Metzger, M.D., an associate member of the St. Jude Department of Oncology and the study's principal investigator, said:

"This is a devastating example of how drug shortages affect patients and why these shortages must be prevented. Our results demonstrate that, for many chemotherapy drugs, there are no adequate substitute drugs available."

Previous shortages have most frequently been solved using substitutions. This study has given a real face to the drug shortage problem, showing that it is real. There are actual therapies that are unable to be given because drugs are just not available.

Michael Link, M.D., the senior author and professor of pediatrics in hematology-oncology at Stanford, as well as a member of the pediatric hematology-oncology service at Packard Children's Hospital, explains:

"Despite heroic efforts by the drug shortage office of the Food and Drug Administration to solve the shortages of a number of medically necessary drugs, it is clear that patients are still suffering from the unavailability of life-saving drugs. A more systematic solution to the problem is needed."

Results of Drug Substitutions

Hodgkin lymphoma is cancer that attacks the lymph system and makes up approximately six percent of childhood cancers. Around 90 percent of patients in the United States with this cancer will become long-term survivors.

In 2002, the five institutions collaborating on this study worked as the Pediatric Hodgkin Consortium and accepted a seven-drug chemotherapy treatment course, which included mechlorethamine, to treat high risk child patients. The researchers aimed to avoid infertility and other issues and maintain high cure rates.

In 2006, a companion study started for patients with intermediate-risk disease. The risk groups are defined by how far the cancer has spread, the location and number of lymph nodes involved, as well as the experience of negative symptoms like night sweats, fever, and weight loss.

Patients underwent 12 weeks of the seven-drug chemotherapy treatment course. They also received radiotherapy with their dose given in accordance to their chemotherapy response. Once mechlorethamine was no longer available, the substitution cyclophosphamide was allowed in its place.

Results for cancer patients are calculated in terms of cancer-free survival, also known as the number of years patients live disease-free. When investigators looked at the substitution's influence, they saw that approximate disease-free survival was 88 percent for the 181 patients whose treatment included mechlorethamine.

For the 40 patients who were given cyclophosphamide, the rate was 75 percent. The variation prompted researchers to stop enrolling new patients in the trials.

As a whole, patients who had the cyclophosphamide experienced less negative symptoms and were more inclined to have intermediate-risk, rather than high-risk Hodgkin lymphoma. The authors note that there is no valid explanation for the significant difference in event-free survival besides the drug substitution.

The patients in the study were between the ages of 3 and 21, with half being under 14 years. Relapsed patients underwent additional therapy. Extra treatment included extensive chemotherapy and a stem cell transplant using the patient's own blood-creating stem cells.

The investigators said it is too early to determine whether these patients will experience the same long-term survival rates as those who did not get their cancer back.

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