Pennsylvania University. US: Results of Phase III Clinical Study of Advanced Kidney Cancer Patients after Surgery Revealed No Survival Benefit for Sunitinib, Sorafenib.
Two widely used targeted therapy drugs— approved by the FDA for use in
metastatic kidney cancer —are no more effective than a placebo in
preventing return of the disease to increase life spans of patients
suffering from advanced kidney cancer after surgery, according to new
results to be presented by a researcher at the University of
Pennsylvania’s Abramson Cancer Center (ACC) during the 2015 Genitourinary Cancers Symposium.
Lead researcher Naomi B. Haas, MD, associate
professor in the Division of Hematology/Oncology and director of the
Prostate and Kidney Cancer Program at the ACC, and her colleagues in
the ECOG-ACRIN Cancer Research Group (ECOG-ACRIN) treated 1,943
patients in the United States and Canada with one year of sorafenib,
sunitinib, or a placebo drug after surgery to resect (cut out) their
kidney tumors. The phase III study found no difference in median years
of disease-free survival in the adjuvant setting: 5.6 years for
sunitinib; 5.6 years for sorafenib; and 5.7 years for placebos.
The findings are one of five abstracts featured in a presscast on
Monday, February 23 at the 2015 Genitourinary Cancers Symposium, which
is co-sponsored by the American Society of Clinical Oncology, the
American Society for Radiation Oncology, and the Society of Urologic
Oncology. The Symposium will take place February 26-28 in Orlando.
While surgery is typically the best initial treatment for renal
tumors, surgical resection alone is not enough to prevent return of the
disease in many patients. Adjuvant therapies (applied after initial
treatment with the goal of suppressing secondary tumor formation) are
often needed to improve survival.
Sunitinib and sorafenib are examples of adjuvant therapies known as
kinase inhibitors. Kinases are proteins on or near the surface of
cells; they help cancer grow and survive. Kinase inhibitors block the
growth of kinases and associated blood vessels which nourish cancers. Sorafenib and sunitinib, which are taken in pill form on a daily basis, are thought to block different kinases.
Both drugs have been shown to be effective when kidney cancer has
spread to other parts of the body. Could they also be effective in preventing recurrence of the disease?
“The current standard of care for these patients is close
observation,” Haas said. “Unfortunately, we found that the use of
sunitinib or sorafenib in this setting did not reduce the incidence of
recurrence as compared to placebo. Fortunately, the use of these drugs
in this setting did not appear to make the outcome of patients
receiving them any worse.”
This study, designed and conducted by ECOG-ACRIN, is the first and
largest trial on the effectiveness of these two kinase inhibitors in
patients whose kidney tumors have been completely removed and who are
at high risk for recurrence. Haas said that there are other ongoing
adjuvant trials investigating different lengths of therapy with
sunitinib and sorafenib, as well as different kinase inhibitors. The
results of these investigations are not yet available and could have
different results than the Penn study.
“It is important to support these trials so we learn how to better treat kidney cancer in the adjuvant setting,” she said.
In the early years of the trial, about a third of patients stopped
treatment because they found the side effects, such as hypertension and
fatigue, of the medications too hard to tolerate.
Patients in the study also contributed blood and urine samples as a
part of their participation. Analyses of these samples may shed light
on who might still benefit or not benefit from sunitinib and sorafenib
in the treatment of kidney cancer in the adjuvant setting. Haas and her
colleagues collected the samples at the beginning of treatment and
subsequent to recurrence of the cancer in patients who suffered a
relapse—and continue to do so more than four years after the formal
conclusion of the study.
“This will afford opportunities to uncover molecular clues and other
information that could help explain why some patients had a recurrence
of their cancer or a spreading elsewhere and others did not,” Haas
said.
ECOG-ACRIN Cancer Research Group is a membership-based scientific
organization that focuses on cancer research involving adults who have
or are at risk of developing cancer. It is comprised of nearly 1100
member institutions, including Penn Medicine.