results of the phase 3 CALGB/SWOG 80702 trial showed.
The trial included 2,526 patients randomized to either 6 or 12 cycles of adjuvant FOLFOX with either celecoxib or placebo. The 3-year disease-free survival (DFS) rate was 76.3% for patients on celecoxib and 73.4% for those on placebo. The 5-year overall survival (OS) was 84% and 81.8%, respectively.
“The addition of celecoxib to FOLFOX adjuvant therapy in stage III colon cancer did not significantly improve disease-free or overall survival,” Jeffrey A. Meyerhardt, MD, of the Dana-Farber Cancer Institute in Boston, said while presenting the results as part of the American Society of Clinical Oncology virtual scientific program.
“We did not detect a significant interaction between celecoxib and duration of FOLFOX therapy for disease-free survival. Similarly, we did not detect a significant interaction between celecoxib and duration of FOLFOX therapy for overall survival,” Dr. Meyerhardt said.
“Simply put, celecoxib should not be used for the secondary prevention of colon cancer,” said invited discussant Christopher Lieu, MD, of the University of Colorado Cancer Center, Aurora.
Trial details
The 80702 trial was designed to test whether the COX-2 inhibitor celecoxib could help further reduce the risk of recurrence when added to adjuvant chemotherapy with 3 or 6 months of FOLFOX. Data on the FOLFOX portion of the trial were previously reported as part of the International Duration Evaluation of Adjuvant Therapy collaboration (N Engl J Med. 2018;378:1177-88).
The trial enrolled 2,526 patients with resected stage III colon cancer. They were randomized to receive 3 or 6 months (6 or 12 cycles) of FOLFOX with either concurrent celecoxib at 400 mg daily (n = 1,265) or placebo (n = 1,261) for 3 years from the start of the trial.
The primary endpoint of 3-year DFS did not differ between the groups (hazard ratio, 0.90; P = .16). Likewise, 5-year OS rates did not differ significantly (HR, 0.89; P = .22).
As Dr. Meyerhardt said, there were no significant interactions detected among any subgroups for DFS or OS, including by age, N or T stage, risk group, concurrent low-dose aspirin use, sex, race/ethnicity, baseline performance status, FOLFOX duration, body mass index, or tumor location.
Rates of toxicities were similar between the groups, except for a higher incidence of hypertension of any grade with celecoxib during FOLFOX therapy (14.6% vs. 10.9%, P = .01) and a grade 2 or greater creatinine increase with celecoxib after FOLFOX (1.7% vs. 0.5%, P = .01).
About 40% of patients completed all 3 years of celecoxib or placebo. Reasons for discontinuation included recurrent disease, adverse events, patient withdrawal from the study, physician decision, or other complicating disease.
Why didn’t it work?
Previous studies have indicated that aspirin and cyclooxygenase (COX)-2 inhibitors are associated with a reduced risk of colorectal polyps and cancer, Dr. Lieu said. So why didn’t celecoxib improve survival in the current trial?
“There are obviously COX-1 and COX-independent targets that aspirin hit that celecoxib does not, and its survival impact of affecting these targets is still largely unclear,” Dr. Lieu said.
He added that ongoing trials – including the Add-Aspirin and ASCOLT studies – should provide more insight.
The current trial was sponsored by the Alliance for Clinical Trials in Oncology in collaboration with the National Cancer Institute. Pfizer provided the celecoxib and placebo. Dr. Meyerhardt disclosed relationships with Cota Healthcare, Taiho Pharmaceutical, and Array BioPharma. Dr. Lieu disclosed relationships with Foundation Medicine, Ipsen, Merck, and Immune Design.
SOURCE: Meyerhardt JA et al. ASCO 2020, Abstract 4003.