WASHINGTON — A combination of gene therapy and drugs is showing promise in treating head and neck cancers, researchers in Texas report.
If borne out in further trials, the findings could point the way to more effective treatment of almost 500,000 people who suffer head and neck cancers annually.
Scientists at the M.D. Anderson Cancer Clinic in Houston report that the combination therapy caused tumors to shrink in 25 of 30 patients tested. Their findings are reported in the August issue of the journal Nature Medicine, published Tuesday.
Cancerous tumors, some as large as 2 1/2 inches, disappeared in eight patients, the scientists reported. In others, the tumors shrank by up to half.
The positive findings are reported as gene therapy has come under close scrutiny after the death of a patient undergoing experimental treatment last September.
The field has been criticized for too much hype and two few successes, said W. French Anderson of the University of Southern California, who was not involved in the newly reported research.
But, Anderson added in an article accompanying the new paper, "Gene therapy seems to be turning the corner after a very bad year."
In the new paper, a team led by the Houston clinic's Fadlo Khuri used a specially engineered virus called ONYX-015, which destroys cells with a mutated tumor suppressor gene called p53. That mutated gene occurs in up to 70 percent of head and neck tumors, the scientists noted. ONYX-015 does not damage normal cells.
Along with the gene therapy, the team added the traditional chemotherapy drugs, cisplatin and 5-fluorouracil, in patients with recurrent squamous cell cancer of the head and neck. These cancers are often associated with the use of tobacco and alcohol.
They reported that ONYX-015 in combination with chemotherapy is more effective than either treatment alone.
Current chemotherapy produces results in only 30 percent to 40 percent of patients, and tumors often recur. By comparison, none of the responding tumors treated with the combination therapy had reappeared after six months.
In the trial, the ONYX-015 was injected directly into the tumors. The scientists suggested that future trials look into other methods of administration and the possibility of using the gene therapy in combination with other methods of treatment, including radiation and surgery.
Besides Khuri, scientists participating in the research represented U.S. Oncology, Dallas; the University of Glasgow, Scotland; Royal Marsden Hospital and the Imperial Cancer Research Fund, both in London; Western General Hospital, Edinburgh, Scotland; Princess Margaret Hospital, Toronto; and ONYX Pharmaceutical, Richmond, Calif.