Cabozantinib (cabo) combined with durvalumab (durva) in gastroesophageal (GE) cancer and other gastrointestinal (GI) malignancies: Preliminary phase Ib CAMILLA study results.
Anwaar Saeed, Milind A. Phadnis, Robin Park, Weijing Sun, Raed Moh’d Taiseer Al-Rajabi, Joaquina Baranda, Stephen K. Williamson, Zachary Collins, Jeanette Firth-Braun, Azhar Saeed, Carolyn A. Foster, Benjamin Roberts, Dharmalingam Subramaniam, Anup Kasi, Shrikant Anant
Abstract
4563 Background: Cabo targets multiple tyrosine kinases, including VEGFR, MET, and AXL, and has been reported to show immunomodulatory properties that may counteract tumor-induced immunosuppression, providing a rationale for combining it with PD-L1 inhibitors like durva. We conducted a phase Ib GI basket trial to evaluate the safety & efficacy of this regimen in advanced GE adenocarcinoma (GEA), colorectal cancer (CRC), & hepatocellular carcinoma (HCC). Methods: Patients received cabo and durva in 3+3 dose escalation then expansion to determine the dose limiting toxicity (DLT), Recommended Phase 2 Dose (RP2D), ORR, PFS & OS. Cabo was dosed at 20mg QD, 40mg QD, and 60mg QD in the first, second, and third cohorts respectively. Durva was dosed at 1500mg IV Q4W in all cohorts. DLT window was 28 days. Scans were obtained every 8 wks. Treatment beyond progression was allowed. Results: 23 Pts (16 M, 7 F), median age 60 yrs (range 33-79) were currently enrolled. 12 in the dose escalation cohort with cabo 20mg (6 pts), or 40mg (3 pts), or 60mg (3 pts). 11 pts enrolled in the dose expansion cohort with cabo 60mg. 8 pts had GEA, 13 pts had CRC, and 2 pts had HCC. Median number of prior chemotherapies was 3 (range 1-3). 3 pts were not evaluable for DLT due to missing ≥30% of DLT window doses, not related to DLT. No DLTs were observed. Drug-related Grade (G) 1&2 AEs included fatigue (83%), abnormal LFTs (39%), anorexia (26%), diarrhea (26%), nausea (13%), & hand foot syndrome (13%). One pt each developed drug related G3 hypertension, hyperthyroidism, thrombocytopenia, & thromboembolic event, all occurring outside the DLT window. 19 pts were evaluable for response: 4 PR (2 GEA & 2 CRC), 12 SD, 3 PD; ORR 21%; clinical benefit rate 84%; median time to PD 16 wks (range 8-40+). Conclusions: RP2D was determined to be Cabo 60mg QD and Durva 1500mg Q4W. Enrollment to phase I dose expansion is ongoing. RP2D may be adjusted based on additional experience & long-term tolerability. Early efficacy data was encouraging. This is an investigator-initiated trial funded by Exelixis & Astrazeneca. Clinical trial information: NCT03539822 .