A phase Ib trial of FOLFIRINOX plus saridegib, an oral hedgehog (Hh) inhibitor, in pts with advanced pancreatic cancer (PDAC).
Andrew H. Ko, MD
Background: FOLFIRINOX has emerged as the optimal 1st-line treatment option for pts with advanced PDAC and good performance status; whether it can serve as the backbone upon which to add targeted agents in clinical trial design remains uncertain. The goal of this multicenter phase Ib study is to evaluate FOLFIRINOX in combination with saridegib, a novel oral agent that inhibits the Hh signaling pathway. In preclinical models of PDAC, saridegib increases chemotherapy delivery by depleting peritumoral stroma and increasing vascularity.
Methods: Pts with previously untreated metastatic or locally advanced PDAC and ECOG PS 0-1 were eligible. Treatment consists of once-daily saridegib with concurrent administration of biweekly FOLFIRINOX (omitting the 5-FU bolus). A 3+3 dose escalation design was used (see dose levels below). Prophylactic WBC growth factor support is mandated. DLT definitions include ALT/AST ≥10x ULN, grade 4 plts or ANC ≥5 d, or grade 3-4 nonheme toxicity. CT scans are obtained every 4 cycles. Limited PK analyses are performed.
Results: Seven pts have been enrolled at the first 2 dose levels. Grade 1-2 AEs include GI (N/V/D), dehydration, fatigue, and LFT abnormalities. There was one DLT (grade 3 ALT elevation) at DL2. Other serious toxicities seen include grade 3 nausea (DL1) and grade 3 diarrhea (DL2). Tumor shrinkage has been observed in all 4 pts at DL1, ranging from 17-54%, with 2 unconfirmed PRs. Final MTD determination and updated safety and efficacy data will be presented at the meeting.
Conclusions: A modified FOLFIRINOX regimen can be safely administered in combination with novel agents in clinical trials of PDAC. While saridegib was not beneficial when added to gemcitabine in a separate randomized phase II study, early evidence of significant responses on the current trial suggests that a more intensive chemotherapy platform may represent a preferable strategy in PDAC trial design.