News report--NOT A PRESS RELEASE!
From today's NYTimes.
Anyone have a stop order in at 84?
May 19, 1998
Man-Made Virus Kills Cancer in Tests
By NICHOLAS WADE
novel form of cancer treatment, based on recent discoveries about the inner working
of tumor cells, has shown impressive results with a small group of patients with
advanced head and neck cancers.
The agent of treatment is a genetically altered adenovirus, one of the viruses that cause the
common cold. The results were presented Monday by Dr. David H. Kirn, medical director
of Onyx Pharmaceuticals, at the American Society of Clinical Oncology meeting in Los
Angeles.
The Onyx virus has been designed to kill cancer cells but spare normal ones by exploiting a
genetic difference between them. This fine discrimination means it can be injected into
tumors in heavy doses without causing harm to the patient other than flu-like symptoms.
The new study is a Phase 2 trial, one in which the developers of an experimental treatment
try to find the best dose and mode of therapy before embarking on the definitive test of a
Phase 3 trial with statistically meaningful numbers of patients.
In the Phase 2 trial reported Monday, 10 patients with advanced head and neck cancer
were given both the virus and two standard chemotherapy agents known as Cisplatin and
5-FU. All patients responded to the treatment. Two had complete regression of their
cancers; the tumors disappeared and no trace of cancerous cells could be seen in tissue
samples inspected with a microscope. The patients cannot be said to be cured, however,
because they have been free of cancer for only 4 months.
Of the other 8 patients, one had a 40 percent shrinkage of the tumor, and seven had
reductions of between 50 percent and 95 percent.
With the chemotherapy agents alone, 35 percent of head and neck cancer patients have a
significant response, meaning their tumors shrink by half or more, compared with the 90
percent response rate seen so far in the new study. Earlier trials with the Onyx virus alone
showed a significant response rate, including two complete remissions among 13 patients,
but the company had hoped the virus would work even better in combination with
chemotherapy.
Experience with the new drug is too short to permit any conclusion about its ultimate
effectiveness, but physicians who have used it are encouraged so far.
"I have treated people for 25 years and have never seen anything quite like this before,"
said Dr. James Arseneau, a medical oncologist at the Albany Medical Center Hospital in
Albany, N.Y.
Arseneau began using Onyx-015, as the genetically engineered virus is called, in January in
treatment protocols designed by the company. So far he has treated 6 patients, all of whom
have responded in varying degrees. He said, "I'm having fun again -- it gives you the heart
and courage to go forward, though we're in a very preliminary phase here."
Dr. Fadlo Khuri, an oncologist at the M.D. Anderson Center in Houston, said that "if this
degree of response holds up, it will be astonishing," but he noted that higher response rates
are often seen in Phase 2 tests than in the more objective Phase 3 trials that follow. He said
all of his three patients have responded to the new treatment.
Kirn, Onyx's medical director, said the virus was being tested in academic centers by
independent experts like Khuri and Arseneau. Onyx covered the patients' costs but made
no payment to the investigators, Kirn said. These investigators, he said, are saying that "it's
not just that everyone is responding, but the magnitude and rapidity of the response is very
unusual."
Many drugs which look promising in early trials often falter at later stages of clinical
testing, and physicians have learned to regard even spectacular individual cases with
circumspection. Nevertheless, the Onyx virus has seemed sufficiently promising to its
sponsor that the company is now testing it against several other kinds of cancers, including
those of the pancreas, ovary and stomach.
The virus works only against tumors which have an inactivated version of a gene that
normally thwarts development of tumors. The P53 gene is inactivated in 50 percent of all
human cancers, and in 70 percent of head and neck cancers.
The Onyx virus was conceived in 1992 by Frank McCormick, then the company's chief
scientific officer and now director of the University of California, San Francisco cancer
center. He saw how the adenovirus could be engineered in a way that made it harmless to
normal cells but lethal to tumor cells with inactive p53 genes.
Onyx Pharmaceuticals is located in Richmond, Calif. Experimental trials of Onyx-015 are
being conducted at 10 centers in the United States, Britain and Canada. |
