SAN FRANCISCOIn an effort to extend the activity of gemcitabine (Gemzar)
against pancreatic cancer, researchers have paired an investigational chimeric
monoclonal antibody, IMC-C225 (cetuximab) with the standard chemotherapy.
IMC-C225 selectively binds to epidermal growth factor receptor (EGFR).
How IMC-C225 Works
Growth factors EGF and TGF-alpha bind to EGF receptor (EGFR)
The phase II trial, involving 40 patients, produced a 1-year overall
survival rate of 32.5% and an increase in time to progression from 2 months for
historical controls to almost 4 months.
James Abbruzzese, MD, chairman, Department of Gastrointestinal Medical
Oncology, M.D. Anderson Cancer Center, reported the results at the 37th Annual
Meeting of the American Society of Clinical Oncology (ASCO abstract 518).
"This work explores the value of targeting specific molecules and
proteins intimately associated with the growth of pancreatic cancer
cells," Dr. Abbruzzese said. "In this case, we looked at targeting
EGFR, known to be important in pancreatic cancer growth." Of the 54
patients screened for the study, more than 90% tested positive for EGFR
expression, a condition for acceptance into the trial.
Compared with historical controls receiving gemcitabine alone, combining
IMC-C225 and gemcitabine more than doubled the response rate, from 6% to 13%,
Dr. Abbruzzese said. At the 1-year point, 32.5% of patients were still alive
with this combined treatment, compared with 18% to 20% of historical control
patients receiving gemcitabine alone.
The most common adverse reactions reported during the study were nausea,
fatigue, and an acne-like rash.
"It looks promising at this point," Dr. Abbruzzese said. "But
we have to confirm it in a larger randomized study." He said that a larger
study is under discussion with the sponsoring company, ImClone Systems
Incorporated. "There’s no written protocol yet," he said, "but
we have discussed how it would be designed and who would be involved. I’m
hoping this will move along quickly so that we have a study ready to go by the
third or fourth quarter of this year."