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Gleevec: Targeted Cancer Therapy Approved 25 Years Ago Transforms Treatment for Chronic Myeloid Leukemia

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Mel Mann’s Story: The First Patient to Defy the Odds

Mel Mann, a former Army major from Detroit, was diagnosed with chronic myeloid leukemia (CML) at age 37 in January 1995. He was given a prognosis of three years to live.

Mann entered clinical trials for experimental drugs, some of which provided temporary benefit. By 1998, his condition had deteriorated significantly. He then enrolled in a trial for the drug that became Gleevec (imatinib), starting in August 1998. By June 1999, he was able to run a marathon.

The Science Behind the Breakthrough

In the 1970s, oncologist Brian Druker proposed targeting the specific genetic driver of cancer rather than using broad chemotherapy. CML was linked to the Philadelphia chromosome, which produces an abnormal enzyme that keeps cell growth permanently 'on.'

Druker sought a compound to inhibit this enzyme. Oregon Health & Science University supported his work. He tested five compounds from the company that would become Novartis. One compound, imatinib (later Gleevec), inhibited the enzyme in lab studies.

Clinical Trials: A Rapid Success

Phase I clinical trials began in 1998, enrolling only CML patients. Within six months, all patients taking a high dose responded to treatment, with generally mild side effects. Due to internet communication, patients worldwide sought enrollment.

"The response was so rapid and so consistent that it changed the course of the disease overnight."

FDA Approval: A Record-Setting Pace

In May 2001, Novartis submitted data to the FDA. Biostatistician Insa Gathmann analyzed survival curves, initially suspecting errors because patients were surviving longer than expected. The FDA approved Gleevec on May 10, 2001, in 72 days—the fastest approval at that time.

Significance: The Dawn of Targeted Therapy

Gleevec is considered the first targeted cancer therapy, ushering in an era of over 100 targeted cancer drugs. However, initial pricing was $26,000 per year, raising access concerns. The drug is now generic and costs a few hundred dollars per year.

Patient Outcomes: A Living Legacy

Druker reports that some patients from the original trial are still alive 25 years later, experiencing life events they were not expected to see. Mann, now 69, plans to run the Boston Marathon.

"I was supposed to die in 1998. Instead, I’m going to Boston."