160272-173

Phase Ib study of cancer stem cell (CSC) pathway inhibitor BBI-608 administered in combination with FOLFIRI with and without bevacizumab (Bev) in patients (pts) with advanced colorectal cancer (CRC).

Subcategory: 
Category: 
Cancers of the Colon, Rectum, and Anus
Session Type and Session Title: 
Poster Session C: Cancers of the Colon, Rectum, and Anus
Abstract Number: 

569

Poster Board Number: 
Poster Session C Board #D18
Citation: 
J Clin Oncol 34, 2016 (suppl 4S; abstr 569)
Author(s): 
Joleen Marie Hubbard, Bert H. O'Neil, Derek J. Jonker, Thorvardur Ragnar Halfdanarson, Alexander Starodub, Axel Grothey, Laura Borodyansky, Chiang Li; Mayo Clinic, Rochester, MN; Indiana University Health University Hospital, Indianapolis, IN; Ottawa Hospital Cancer Centre, Ottawa, ON, Canada; Mayo Clinic, Scottsdale, AZ; Indiana University Health Goshen Center for Cancer Care, Goshen, IN; Boston Biomedical, Inc., Cambridge, MA

Abstract Disclosures

Abstract: 

Background: BBI-608 is an oral first-in-class cancer stemness inhibitor that blocks STAT3-mediated transcription of cancer stemness genes. Potent anti-CSC activity was observed in vitro and in vivo,in mono and combination therapy. In phase I studies, BBI-608 was generally well tolerated with encouraging signs of anti-tumor activity. Methods: A phase Ib open label, multi-center study in pts with advanced CRC was undertaken to confirm the RP2D of BBI-608 in combination with FOLFIRI with or without BEV. BBI-608 was administered at 240 mg BID in combination with FOLFIRI (5-FU 400 mg/m2 bolus with 2400 mg/m2, irinotecan 180 mg/m2, and leucovorin 400 mg/m2infusion) with or without BEV 5 mg/kg, administered bi-weekly until progression of disease, unacceptable toxicity, or other discontinuation criterion was met. Results: 18 heavily pretreated pts with an average of > 3 prior lines of therapy of which 10 pts (56%) previously progressed on FOLFIRI were enrolled. Of the 17 pts evaluable for response, 8 pts received FOLFIRI and 9 pts received FOLFIRI with BEV in combination with BBI-608. Most common adverse events included grade 1 and 2 diarrhea, abdominal pain, nausea, vomiting and anorexia. No dose limiting toxicity or new adverse events were seen, and the safety profile was similar to that of each regimen as monotherapy. Grade 3 events related to protocol therapy included diarrhea occurring in 3 pts, fatigue in 2 pts and dehydration in 1 pt. All events resolved after dose reduction and/or start of anti-diarrheal medications. No significant pharmacokinetic interactions were observed. Disease control (PR+SD) was observed in 16 of 17 evaluable pts (94%) with 2 PR (per RECIST 1.1 criteria: 44% and 33% regression) and 14 SD (of which 13 (93%) had tumor regression < 25%). In the evaluable pts, median progression free survival was 5.54 months. Of 17 pts, 7 (41%) had prolonged SD of > 6 months. Conclusions: This phase Ib study confirmed that BBI-608 at 240 mg bid can be safely combined with FOLFIRI with and without BEV, and shows encouraging anti-tumor activity in heavily pretreated CRC pts, even in pts with prior progression on FOLFIRI-based therapy. Clinical trial information: NCT02024607