The meeting of the American Society of Clinical Oncology in Atlanta on June 2-6 showcased many incremental advances. Taken together, they bolster a new approach to treatment using targeted drugs that may someday make a huge difference to patients.
One reason cancer drug development is so difficult is that there are few ways to gauge the effect of experimental drugs early on. Invasive tumor biopsies are risky, tests for "markers" in the blood that help doctors track disease aren't available for most cancers, and many imaging technologies aren't sufficiently precise.
For help, researchers are turning to an imaging technique called functional positron emission tomography, or F-PET. The images above show how gastrointestinal tumors "switch off" once the patient receives nilotinib, an early-stage Novartis (NVS) drug aimed at patients who have grown resistant to the company's blockbuster Gleevec.
The response shown here is after 28 days of treatment, but the effect is visible after just 7 days. "It would normally be extremely difficult to determine if a drug is hitting the target that early on," says Dr. Annick Van den Abbeele of Dana-Farber Cancer Institute, who led the study. Investigators have started talks with the Food & Drug Administration about using F-PET scans of certain tumors as a way of assessing a drug's performance.
Some of the best news out of the ASCO meeting was for patients with kidney cancer. It's the target of a number of new drugs, including one that appears to prolong survival, the gold standard of cancer drug trials.
Kidney cancer killed about 11,000 Americans last year, most of them in less than one year from time of diagnosis. For more than 20 years, the standard treatment has been highly toxic chemotherapy, which causes myriad side effects. But already this year, the FDA has approved two promising targeted treatments, Pfizer's (PFE) Sutent and Nexavar, made by Bayer Pharmaceuticals (BAY) and Onyx Pharmaceuticals (ONXX).
Wyeth Pharmaceuticals hopes to add a third weapon to this arsenal. Temsirolimus, its experimental drug, blocks a protein called mTOR that regulates the growth of both cells and the blood vessels that feed tumors. In a study of 226 patients with advanced kidney cancer, the group that received the Wyeth drug lived a median of 10.9 months, vs. 7.3 months for those on standard chemo. Other drugs have shrunk kidney tumors, but this is the first to show that patients can live longer.
Can drugs induce cancer cells to commit suicide? That's the goal of Apo2L/ TRAIL, a protein jointly developed by Genentech (DNA) and Amgen (AMGN) that activates two different cell-suicide pathways. In the first clinical trial of the drug, cancer growth was halted in 26 of 37 patients assessed.
A second cell-suicide drug, Astellas Pharma's YM155, was tested in 41 patients with non-Hodgkins lymphoma, prostate cancer, and colon cancer. The tumors shrank in five. Side effects for both drugs were far less than found with standard chemo.
-- Gardasil, a vaccine from Merck (MRK), is poised to win FDA approval in June for preventing cervical cancer. But it also appears to be effective against vaginal and vulvar cancers that are caused by the same human papillomavirus (HPV), which is transmitted mainly through sexual intercourse. Researchers led by Dr. Jorma Paavonen of the University of Helsinki in Finland combined data from three trials evaluating the vaccine in a total of 18,150 women. All were tumor-free.
-- Cancer is not only difficult to treat, the medicines themselves can be debilitating. So oncologists are scrambling for ways to improve patients' quality of life. Doctors at M.D. Anderson Cancer Center believe that yoga may help. In a trial of 61 women with breast cancer who were undergoing radiation, half were assigned to a very simple weekly yoga program. The practitioners reported significantly better physical and social functioning, and lower levels of fatigue and sleep disorders, than the control group. But members of both groups continued to suffer equally from depression and anxiety -- states that don't seem to respond to stretching.