Print(PDF/161KB) Jan. 23, 2017 R&D

Sumitomo Dainippon Pharma Announces Clinical Data of Investigational Cancer Stemness Inhibitor Napabucasin were presented at 2017 ASCO GI Symposium

Sumitomo Dainippon Pharma Co., Ltd. (Head Office: Osaka, Japan; President: Masayo Tada; “Sumitomo Dainippon Pharma”) announced today that two poster presentations of napabucasin (BBI608) were delivered on January 21, 2017 (U.S. time) at the 2017 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium, January 19 to 21, 2017, in San Francisco.

Overview of poster presentations at the ASCO-GI

1. Results of Phase 1b/2 study of napabucasin with FOLFIRI, or FOLFIRI and bevacizumab administered to colorectal cancer patients. (BBI608-246: NCT02024607)

Abstract Number 593
Title Cancer stemness inhibition and chemosensitization: Phase Ib/II study of cancer stemness inhibitor napabucasin (BBI608) with FOLFIRI +/- bevacizumab (Bev) administered to colorectal cancer (CRC) patients (pts)
Lead presenter Johanna Bendell, Sarah Cannon Cancer Research Institute/Tennessee Oncology, Nashville, TN
Overview of the study result 63 CRC pts with an average of >2 prior therapy lines were enrolled. This phase Ib/II study suggests napabucasin may sensitize chemorefractory CRC to FOLFIRI +/- Bev and encouraging signs of synergistic activity was observed in CRC pts regardless of p-STAT3 status.
Safety No pharmacokinetic interactions or dose-limiting toxicity was observed. Most common adverse events (AEs) included grade 1/2 diarrhea, nausea, vomiting and fatigue. 1 pt had grade 4 diarrhea and 27 pts had grade 3 AEs, including diarrhea (14), fatigue (4), dehydration (2), electrolyte imbalance (4), nausea (1), vomiting (1), abdominal pain (1) and weight loss (1), all of which resolved with dose reduction and supportive care.
Efficacy Among 56 pts enrolled who received RECIST evaluation, disease control rate(DCR: CR+PR+SD) was observed in 88%(49 pts) with an overall response rate(ORR: CR+PR) of 29%(16 pts) with 1 pt achieving CR.
(Reference: DCR and ORR)
Subset DCR ORR
Evaluable ITT Evaluable ITT
FOLFIRI naïve 93% (28/30) 82% (28/34) 33% (10/30) 29% (10/34)
FOLFIRI exposed 81% (21/26) 72% (21/29) 23% (6/26) 21% (6/29)
p-STAT3high 84% (26/31) 79% (26/33) 26% (8/31) 24% (8/33)
p-STAT3low 92% (23/25) 77% (23/30) 32% (8/25) 27% (8/30)

2. Results of Phase 1b/2 study of napabucasin with panitumumab administered to K-ras wild-type patients with metastatic colorectal cancer (BBI608-224: NCT01776307)

Abstract Number 677
Title BBI608-224: A phase Ib/II study of cancer stemness inhibitor napabucasin (BBI608) administered with panitumumab in K-ras wild-type patients with metastatic colorectal cancer.
Lead presenter Tim Larson, Minnesota Oncology, Minneapolis, MN
Overview of the study result 72 pts were enrolled, 48 pts were evaluable by RECIST of which 7 (15%) and 41 (85%) had 2 or ≥3 prior treatment lines, respectively. Of the 48 evaluable pts, 37 (77%) were previously treated with an anti-EGFR agent.
Napabucasin was safely combined with panitumumab at full dose with no unexpected adverse events and no evidence of pharmacological interaction.
Encouraging anti-tumor activity in pts with K-ras, wt mCRC was observed. Napabucasin may sensitize pts to repeat anti-EGFR therapy.
Safety The safety profile was consistent with that of each agent as monotherapy and most common AEs included grade 1/2 diarrhea, nausea, abdominal cramps, and vomiting.
Efficacy Among 48 pts enrolled who received RECIST evaluation, Disease Control Rate (DCR) was observed in 54.2%(26 pts) of which 2 pts achieved PR (4%) and 24 pts achieved SD (50%). Among 37 pts previously treated with anti-EGFR therapy, DCR was observed in 54%(20 pts) compared with DCR of 54.5% observed in 6 out of 11 anti-EGFR naïve pts receiving a scan.
(Reference: mPFS and mOS)
Population Subgroup mPFS (months) mOS (months)
ITT Anti-EGFRNaïven=18 3 13.3
Anti-EGFRExposedn=54 2.1 9.1
Totaln=72 2.1 9.1
Evaluable Anti-EGFRNaïven=11 3.9 17.9
Anti-EGFRExposedn=37 2.6 9.9
Totaln=48 3 12.2

(Reference)

About napabucasin (BBI608) Napabucasin is an investigational first-in-class anti-cancer agent created and currently under development by Boston Biomedical, Inc. Napabucasin is an orally-administered small molecule agent designed to inhibit cancer stemness pathways by targeting STAT3.

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