Taxol – A Natural Cure for Cancer?

Taxol

In this post we explore the cost to develop a natural product cure.

The National Cancer Institute’s web site declares, Paclitaxel, the most well-known natural-source cancer drug in the United States, is derived from the bark of the Pacific yew tree. Paclitaxel is the generic name for Taxol, and an illuminating case in the development of natural medicines.

Flash back to the 1950s, a period of postwar optimism and prosperity. Science is making significant strides. Penicillin, accidentally discovered in mold, proved to be a potent antibiotic during World War II. During the same period, the scourge of World War I, mustard gas, was shown to be an effective chemotherapeutic agent (the first) against lymphoma. Medicine was transitioning mainly diagnoses to actual cures.

A key catalyst in the development Taxol was Mary Lasker, founder of the Lasker Foundation.  Through the American Cancer Society, she campaigned successfully to significantly increase the funding the the National Cancer Institute (NCI).

Hoping to build on the success of natural sources (Penicillin) and chemotherapy (mustard gas), the NCI contracted with the US Department of Agriculture (USDA) to collect samples.  In 1962 they found what became Taxol.

Discovery of Taxol

Discovery of Taxol plaque: Near this location on August 21, 1962, Arthur Barclay and a team of botanists from the U.S. Department of Agriculture collected bark of the Pacific yew, Taxus brevifolla Nutt. Drs. Monroe Wall and Mansukh, of Research Triangle Institute, North Carolina, under contract to the U.S. National Cancer Institute, isolated Taxol from that sample.

So, just to summarize, TEN YEARS into the search, this important medication was discovered in the bark of the Pacific yew. 10 years.

Actually not much happened in 1962. Yews were already well known to be poisonous. People in Europe had been using this poison for over 2,000 years very effectively. Researchers tended to avoid yew poisons because the conventional wisdom was they these poisons had no specificity-they killed everything.

Monroe Wall and Mansukh Wani at the Research Triangle Institute in North Carolina accepted the challenge and by 1971 they isolated Taxol from the yew bark. Progress was slow because a 1/2 gram of Taxol required 12 kilograms of bark or 6 trees.

Interest waned another 5 years until Susan Horowitz and coworkers at Albert Einstein College of Medicine in New York City discovered the Taxol mechanism of action was unique and seemed to be effective against several cancers in animal models.

Let’s summarized again. Another 14 year of basic science before real interest is generated.  Studies in human cancer patients were begun at Johns Hopkins University in Baltimore and had some success.

In July 1977 Matthew Suffness of the NCI placed an order with the USDA for 7,000 pounds of bark, which meant killing about 1,500 trees. The environmentalists got involved, but research continued even though more and more trees were being harvested.

1024px-Taxol(Paclitaxel)3D

In 1984, NCI began Phase I (safety) clinical trials. There were many other hurdles, but perhaps the major one was cleared when a team of Florida State University Taxol researchers led by Bob Holton synthesized the drug on Dec. 9, 1993-no more killing trees.

This was not a moment too soon, as the FDA had approved Taxol a year earlier. Taxol sales peaked at $1.6 billion in 2000.

Final summary: natural product from the Pacific yew in 1962 became an important anti-cancer treatment in 1993, over 30 years later, 30 years of biology, chemistry, experiments, and trials. No other industry invests so much money over such a long period as the pharmaceutical industry. Compare this to the investors in Google who saw tremendous returns on their investments when Google went public in less than ten years. Most high-tech investors expect their returns much sooner than 10 years even. Other industries have similar or even shorter time horizons.

Pharmaceutical companies are the heroes of capitalism.

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Categories: Pharmaceutical Industry | Tags: , , , , | Leave a comment

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