- Jan 11, 2008
- The Blockbuster Mentality
- Drugs for Smaller Patient Populations Drive Costs Even Higher
- Business Decisions Encroach on Medical Advances
- Sacrificed on the Altar of Market Size
- How We Got Here
Business Decisions Encroach on Medical Advances
Scientific and technological advances make it possible for researchers to focus on the differences in how individuals respond to medicines by identifying sequences of human genes that correlate with whether patients will benefit from a given treatment. This concept is a veritable revolution in clinical drug development—the long-anticipated personalized medicine. This revolution is driven by something called biomarkers, which are fragments of DNA sequences that cause disease or are associated with susceptibility to disease.
So far, disease-specific or drug-specific biomarkers have been identified for chronic diseases, including diabetes and asthma, as well as various forms of cancer. Herceptin, which was discussed previously, is possibly the best example of a current drug whose use depends on the presence of a genomic biomarker. There’s even a molecular diagnostic test to predict which breast cancer patients will benefit from treatment. This is only the beginning. As scientists pore through huge volumes of data collected from sequencing the full human genome (people’s genetic makeup) and relate the data to observations in the laboratory and to presentations of disease symptoms, they’re going to discover many, many more biomarkers.
We don’t use the word revolution lightly. Biomarkers already have a great influence over how clinical trials are designed and conducted. If researchers can develop a molecular diagnostic test, based on their knowledge of biomarkers, to predict which patients will benefit from taking a medicine, clinical trials can enroll a more homogeneous group and conceivably fewer human subjects and still be able to establish whether a new drug is superior to an earlier therapeutic alternative. It’s the kind of cutting-edge scientific advance pharmaceutical firms should fully embrace.
But what if we told you that this tremendous medical breakthrough is being squandered in the name of profit or out of competitive fear? What if we told you that patients are not accessing potentially powerful cancer medications as fully as possible because of a business issue with biomarkers?
Scientists working in large pharmaceutical firms tell us that financial considerations are getting in the way of fully and rapidly realizing the promise of biomarkers. Who loses? All of us. Consider the tale of Iressa and Tarceva.
In the 1960s, scientists observed that kinase enzymes play an essential role in the growth of certain cancers, and so they began to explore how to block the action of kinase. It took decades before the first kinase inhibitor drug made it to market. In 2001, Novartis introduced Gleevec, “hailed as a miracle drug poised to usher in a new age in cancer treatment.”15 The drug targets genetic aberrations leading to two infrequently occurring cancers, chronic myeloid leukemia and gastrointestinal stromal tumors.16 As we previously mentioned, therapy with this drug has produced major survival benefits for patients.
Iressa and Tarceva are two newer targeted kinase inhibitors, which address genetic mutations that have major roles in producing certain types of non-small cell lung cancer (NSCLC), a condition for which older chemotherapies have not produced much survival benefit. (These drugs are also used on or off label to treat a number of other cancers.) Iressa, approved—although with some controversy—by the FDA in 2003, was discovered and developed by AstraZeneca. While only about 10 percent of patients in the trials for Iressa demonstrated shrinkage in tumor size, the FDA gave its okay to get this much-needed therapy to market quicker.
Once the drug was on the market, published reports showed that patients appeared to develop serious complications disproportionately, including lung disease and stroke.17 Late in 2004 and early in 2005, two clinical trials demonstrated convincingly that patients treated with Iressa did not live longer than those treated with traditional chemotherapy. Meanwhile, many oncologists were observing striking improvements—including arrested disease progression and extended survival—among a small proportion of NSCLC patients they were treating. Several academic and commercial research groups, all independent of AstraZeneca, went on to develop laboratory tests that appear to predict which small, specific subgroups of patients with NSCLC actually benefit from this drug. It appeared that a biomarker was at work here, so the FDA reviewed the new information and, late in 2005, required a change in Iressa’s label. The FDA severely restricted access to the drug to those most likely to benefit.18 AstraZeneca could no longer reap the profits through sales of the drug to people for whom it wasn’t likely to work.
The FDA’s reclassification of Iressa was made easier because of the agency’s experience with Tarceva, a drug that competes with Iressa. Tarceva was discovered by a small research firm, then developed by a larger biotechnology company, and today is distributed by the pharmaceutical firm that now owns a majority stake in the developer. Clinical trials were outsourced. Using biomarkers, Tarceva’s human studies demonstrate an improved survival of additional months, among NSCLC patients who continue to be treated with it, compared to patients receiving traditional chemotherapy.
The point here is that Iressa’s manufacturers did not bother to identify a biomarker predictive of the drug’s response or toxicity—at least not for the FDA. In fact, the pharmaceutical industry has been quite slow to embrace, at least publicly, the concept of biomarkerenabled medications. Iressa’s biomarker was identified by the university researchers in Boston and New York, and only after they observed that the drug produced unmistakable benefits in an extremely small proportion of patients.