Sotorasib, an approved treatment for lung cancer, has demonstrated clinically meaningful anticancer activity and tolerability in patients with heavily pretreated KRASG12C-mutated advanced pancreatic cancer.
The findings were reported at the American Society of Clinical Oncology Genitourinary Cancers Symposium.
“This is clinically meaningful for patients because there is not an established standard therapy for these patients once they get to a third line of treatment,” said the study’s author John H Strickler, MD, of Duke University Medical Center, Durham, N.C.
The study, called CodeBreaK100, is an open-label global phase 1 and 2 trial. It consists of the largest dataset evaluating efficacy and safety of a KRASG12C inhibitor in patients with stage 4 pancreatic cancer.
Survival with Food and Drug Administration–approved second-line therapy in pancreatic ductal adenocarcinoma is 6 months with a 16% response rate. No therapies have demonstrated survival benefit after progression on first- and second-line chemotherapy. Among the 90% of pancreatic ductal adenocarcinoma tumors which harbor a KRAS mutation, 1%-2% are p.G12ac mutations.
The study included 38 patients (median age, 65.5 years; 76.3% male) with locally advanced or metastatic pancreatic malignancies who received oral sotorasib (960 mg once daily).
The patients in the trial received one or more prior systemic therapies (79% received two; range, one to eight) or were intolerant or ineligible for available therapies. The primary endpoint was complete plus partial response by blinded independent central review (RECIST 1.1).
Confirmed objective response were reported in 8 patients (21.1%; 95% confidence interval, 9.55%-37.22%) with disease control in 32 (84.2%; 95% CI, 68.75%-93.98%). The median duration of response was 5.7 months. After a median follow-up of 16.8 months, median progression-free survival was 4.0 months (95% CI, 2.8-5.6), and median overall survival was 6.9 months (95% CI, 5.0-9.1).
Once-daily sotorasib was well tolerated. The only treatment-related adverse events above grade 2 were six (15.8%) grade 3 events, with diarrhea in two and fatigue in two (each 5.3%), and single occurrences (2.6%) of abdominal pain, ALT/AST increase, pleural effusion and pulmonary embolism. Three adverse events were serious (7.9%), and no adverse events led to sotorasib discontinuation or were fatal.
Dr. Strickler described the case of a 64-year-old female with stage IV pancreatic cancer at diagnosis, who had baseline metastatic lesions in the liver, lymph nodes, lung and peritoneum. She received prior FOLFIRINOX first line until disease progression. With once-daily sotorasib, time to treatment response was 1.3 month, duration of response was 5.8 months, progression-free survival and overall were 7.1 months each.
Pointing to the centrally confirmed objective response rate of 21.1% and the disease control rate of 84.2%, Dr. Strickler observed in an interview that the CodeBreaK100 data support further exploration of sotorasib in this population with high unmet medical need and that based on these data, the CodeBreaK 100 clinical trial will be expanded to enroll more patients with pancreatic cancer and other tumor types.
The study was funded by Amgen.