Abou‐Alfa, Ghassan K.

266 Background: CCA is a rare cancer for which there are limited effective therapies. IDH1 mutations occur in ~20% of intrahepatic CCAs, resulting in production of the oncometabolite D-2-hydroxyglutarate, which promotes oncogenesis. IVO (AG-120) is a first-in-class, oral, small-molecule inhibitor of mutant IDH1 (m IDH1). ClarIDHy aimed to demonstrate the efficacy of IVO vs PBO in pts with unresectable or metastatic m IDH1 CCA. The primary endpoint was met with significant improvement in progression-free survival (PFS) by independent radiology center (IRC) with IVO vs PBO (hazard ratio [HR] = 0.37, p < 0.0001). Objective response rate (ORR) and stable disease for IVO were 2.4% (3 partial responses) and 50.8% (n = 63) vs 0% and 27.9% (n = 17) for PBO. IVO pts experienced significantly less decline in physical and emotional functioning domains of quality of life at cycle 2 day 1 vs PBO pts (nominal p < 0.05). Methods: Pts with m IDH1 CCA were randomized 2:1 to IVO (500 mg PO QD) or matched PBO and stratified by prior systemic therapies (1 or 2). Key eligibility: unresectable or metastatic m IDH1 CCA based on central testing; ECOG PS 0–1; measurable disease (RECIST v1.1). Crossover from PBO to IVO was permitted at radiographic progression. Primary endpoint: PFS by IRC. Secondary endpoints included overall survival (OS; by intent-to-treat), ORR, PFS (by investigator), safety, and quality of life. The planned crossover-adjusted OS was derived using the rank-preserving structural failure time (RPSFT) model. Results: As of 31 May 2020, ~780 pts were prescreened for an IDH1 mutation and 187 were randomized to IVO (n = 126) or PBO (n = 61); 13 remain on IVO. Median age 62 y; M/F 68/119; 91% intrahepatic CCA; 93% metastatic disease; 47% had 2 prior therapies. 70% of PBO pts crossed over to IVO. OS data were mature, with 79% OS events in IVO arm and 82% in PBO. Median OS (mOS) was 10.3 months for IVO and 7.5 months for PBO (HR = 0.79; 95% CI 0.56–1.12; one-sided p = 0.093). The RPSFT-adjusted mOS was 5.1 months for PBO (HR = 0.49; 95% CI 0.34–0.70; p < 0.0001). Common all-grade treatment emergent adverse events (TEAEs, ≥ 15%) in the IVO arm: nausea 41%, diarrhea 35%, fatigue 31%, cough 25%, abdominal pain 24%, decreased appetite 24%, ascites 23%, vomiting 23%, anemia 18%, and constipation 15%. Grade ≥ 3 TEAEs were reported in 50% of IVO pts vs 37% of PBO pts, with grade ≥ 3 treatment-related AEs in 7% of IVO pts vs 0% in PBO. 7% of IVO pts experienced an AE leading to treatment discontinuation vs 9% of PBO pts. There were no treatment-related deaths. Conclusions: IVO was well tolerated and resulted in a favorable OS trend vs PBO despite a high rate of crossover. These data – coupled with statistical improvement in PFS, supportive quality of life data, and favorable safety profile – demonstrate the clinical benefit of IVO in advanced m IDH1 CCA. Clinical trial information: NCT02989857.

4508 Background: The combination of dual immune checkpoint inhibitors (ICI) T (anti–CTLA-4) and D (anti–PD-L1) showed tolerability with a promising objective response rate (ORR) in the initial cohort of this study (NCT02519348). Subsequent evaluation of pts with solid tumors treated with increasing doses of T suggested priming with a higher dose of T may induce a stronger immune response and enhance anti-tumor activity. Thus, the randomized expansion cohorts comprised 4 arms evaluating T and D as monotherapies and 2 T+D regimens, including a novel T+D regimen featuring a single, priming dose of T. Methods: ICI-naïve pts with aHCC who progressed on, were intolerant to, or refused sorafenib were randomized to one of two T+D combinations: T300+D (T 300 mg + D 1500 mg 1 dose followed by D Q4 weekly [Q4W]) or T75+D (T 75 mg Q4W + D 1500 mg Q4W [4 doses] followed by D Q4W); or single agent D (1500 mg Q4W) or T (750 mg Q4W). Safety was the primary endpoint. ORR by blinded, independent central review using RECIST v1.1, duration of response (DoR), circulating lymphocytes, and overall survival (OS) were assessed. Results: At data cut-off (09/02/2019), 332 pts were enrolled. Median follow-ups were 11.7 months (mo) for T300+D, 14.6 (T75+D), 8.9 (D), and 15.8 (T). Treatment-related adverse event (trAE) incidences are shown (Table); no deaths were attributed to trAEs for T300+D or T. The T300+D arm had the highest confirmed ORR (DoR not reached [NR]) and longest OS (Table). A unique proliferative T cell profile was identified for pts in the T300+D arm, suggesting additive biologic activity for the combination, and showed pts with an OR exhibited high cytotoxic (CD8) counts. Conclusions: The encouraging clinical activity and tolerable safety profile suggest T300+D provides the best benefit-risk profile as opposed to T75+D or monotherapies. The unique pharmacodynamic activity of the T300+D regimen further supports its use in aHCC. T300+D and D are being evaluated in the ongoing phase III HIMALAYA study (NCT03298451) in first-line HCC vs sorafenib. Funding: AstraZeneca. Clinical trial information: NCT02519348 . [Table: see text]

TPS597 Background: Deregulation of the FGFR signaling pathway is implicated in various cancers. In iCCA, FGFR genetic aberrations include FGFR2 fusions and, less commonly, FGFR2 M/A. iCCA prognosis is poor, and chemotherapeutic and targeted treatment options are limited. While FGFR2 fusions are acknowledged oncogenic drivers, the oncogenic potential of FGFR2 M/A is less well defined. Derazantinib (DZB) is an investigational, oral small-molecule kinase inhibitor with activity against FGFR1, 2 and 3, which demonstrated antitumor activity in patients with unresectable iCCA with FGFR2 fusions. Based on preliminary efficacy data demonstrating durable responses of > 6 months and a clinically meaningful progression-free survival in a subset of iCCA patients harboring FGFR2 M/A (NCT01752920), the multicenter, multicohort open-label phase 2 study FIDES-01 is evaluating the effect of DZB in separate cohorts of iCCA patients with FGFR2 fusions or FGFR2 M/A. Methods: The new cohort evaluates 300 mg once daily dosing of DZB in patients with unresectable iCCA with FGFR2 M/A per liquid or tissue biopsy-based next generation sequencing and at least one previous systemic therapy. Treatment will continue until progressive disease, intolerance, withdrawal of informed consent, or death. Using a Simon’s two-stage design, the primary endpoint to assess the antitumor activity of DZB is the proportion of patients with PFS at 3 months (PFS3; per RECIST 1.1 central review). Secondary objectives are evaluation of median PFS, objective response rate, duration of response, safety profile, quality of life (incl., QLQ-C30, QLQ-BIL21, EQ-5D), and symptom response from baseline. Current status: The study was initiated in July 2019 with planned enrollment of 43 patients with confirmed FGFR2 M/A. Clinical trial information: NCT03230318.

TPS462 Background: Dysregulation of fibroblast growth factor receptor (FGFR) signaling by FGFR genetic alterations is implicated in many cancers, including cholangiocarcinoma (CCA). FGFR2 translocations with fusion partners occur in ≈10% to 20% of intrahepatic CCA tumors. Pemigatinib is a selective oral inhibitor of FGFR-1, 2, 3. Preliminary data from the ongoing phase 2 study show efficacy and tolerable safety in patients (pts) with CCA with FGFR2 translocations. We present the design for a phase 3, open-label, randomized trial investigating pemigatinib monotherapy versus gemcitabine plus cisplatin chemotherapy in the first-line treatment of pts with advanced/metastatic or unresectable CCA with FGFR2 rearrangement. Methods: Eligible pts (target, N = 432) are ≥ 18 years (≥ 20 years for Japanese pts) and have ECOG performance status ≤ 1 and histologically confirmed advanced (locally advanced, metastatic, or recurrent) CCA with a documented FGFR2 rearrangement. Key exclusion criteria include prior systemic therapy, excluding adjuvant/neoadjuvant treatment completed ≥ 6 months before enrollment; current evidence of clinically significant corneal or retinal disorder; history of calcium and phosphate homeostasis disorder or systemic mineral imbalance with ectopic calcification of soft tissues; and known, untreated CNS metastases or history of uncontrolled seizures. Pts are randomized 1:1 and stratified by geographic region and tumor burden into 2 treatment groups: pemigatinib starting dose 13.5 mg once daily continuously on a 3-week cycle; or gemcitabine (1000 mg/m2) and cisplatin (25 mg/m2) administered intravenously on days 1 and 8 of every 3-week cycle for up to 8 cycles until disease progression or unacceptable toxicity. Crossover to pemigatinib may be allowed once progressive disease is confirmed. The primary endpoint is progression-free survival (based on independent central review using RECIST v1.1). Secondary endpoints include overall response rate, overall survival, duration of response, disease control rate, safety and tolerability, and impact on quality of life. Clinical trial information: NCT03656536.

408 Background: Standard of care for CCA/GBC is C-G therapy. MAbs (ATZ, pembrolizumab) targeting PD-L1 show promise in treating CCA/GBC. Hyaluronan (HA), which may impede drug and immune cell access, is high (67%) in CCA/GBC tumors. PEGPH20 enzymatically degrades HA. HALO 110-101 (NCT03267940) evaluates safety and activity of PEG-C-G-ATZ or PEG-C-G versus C-G in CCA/GBC pts. Methods: This study comprises two parts. In Run-In (RI) six pts were enrolled in PEG-C-G arm, then six pts in PEG-C-G-ATZ arm. Eight additional pts may be enrolled for tolerability. In Expansion (EX), up to 50 pts will be enrolled for efficacy. Treatment (Tx) cycle is 21 days (d). PEGPH20 dose is 3 μg/kg on d1, eight and 15 and ATZ dose is 1200 mg (one–three hours after PEGPH20) on d1 (PEG-C-G-ATZ only). C-G is dosed at 25 mg/m2 C and 1000 mg/m2 G on d2 and nine. In C-G arm (EX only), C-G is dosed on d1 and 8. Primary endpoints are ORR (RECIST v1.1), AEs (NCI CTCAE v4.03), laboratory/safety (RI only); secondary endpoints are PK; DOR, DCR, PFS; OS, OS by PD-L1 expression; ORR and DOR (imRECIST). Results: Eighteen pts have been enrolled (nine in each arm). The mean (SD) age is 57 (12.2) yrs in PEG-C-G and 69 (8.8) yrs in PEG-C-G-ATZ. 56% were men. All pts experienced ≥ 1 AE. The most common AEs are nausea, fatigue (50% each); decreased appetite (44%); anemia, constipation (39% each); thrombocytopenia, oedema peripheral, AST increased, myalgia (33% each). To date, there has been one dose-limiting toxicity (febrile neutropenia) in the PEG-C-G arm. There have been no deaths due to AEs. Conclusions: The overall safety profile of PEGPH20 + C + G ± ATZ is acceptable and consistent with safety observed for the individual components. There were no DLTs resulting in a dose reduction of PEGPH20, which is being dosed at 3 μg/kg in the EX phase. Clinical trial information: NCT03267940. [Table: see text]

TPS545 Background: Advanced cholangiocarcinoma (CC) is a life-threatening disease with limited effective chemotherapy options. Mutations in isocitrate dehydrogenase 1 (mIDH1) occur in 13–15% of CC cases, and up to 25% of intrahepatic CC cases, leading to epigenetic and genetic changes that promote oncogenesis via production of the oncometabolite 2-hydroxyglutarate (2-HG). AG-120 (ivosidenib), a first-in-class oral mIDH1 inhibitor, displayed a favorable safety profile and clinical activity in a phase 1 study enrolling 73 mIDH1 CC patients who had received ≥1 prior systemic regimen. As of 10 Mar 2017, 4/73 (5%) had a partial response and 41/73 (56%) stable disease. Progression free survival (PFS) rates at 6 months and 12 months were 38.5% and 20.7%, respectively. The 500 mg once daily dose level of AG-120 was selected for further development in mIDH1 CC. Methods: ClarIDHy is a global, phase 3, multicenter, double-blind, randomized (2:1) study of AG-120 (500 mg once daily) vs. matched placebo in 186 mIDH1 CC patients (ClinicalTrials.gov NCT02989857). Key eligibility criteria: non-resectable or metastatic CC, documented mIDH1 by central laboratory testing, ECOG performance status 0–1, measurable disease (RECIST v1.1), documented disease progression after ≤2 prior systemic therapies in the advanced setting including at least 1 gemcitabine- or 5-fluorouracil-containing regimen, and no prior mIDH inhibitor therapy. Crossover from placebo to AG-120 will be allowed at time of radiographic disease progression. Primary endpoint: PFS assessed by independent radiologists. Secondary endpoints: safety, tolerability, overall response rate (RECIST 1.1), overall survival, pharmacokinetic/pharmacodynamic analyses, and quality of life (EORTC QLQ-C30 and QLQ-BIL21 scales). An independent data monitoring committee will monitor the data during study conduct. The ClarIDHy study is currently activated at participating sites in the US, UK, EU, and S. Korea. R eused with permission from the American Society of Clinical Oncology (ASCO). This abstract was accepted and previously presented at the 2017 ASCO Annual Meeting. All rights reserved. Clinical trial information: NCT02989857.

TPS543 Background: Cholangiocarcinoma (CCA) is treated with CIS and GEM (CISGEM), but prognosis is poor. Hyaluronan (HA) accumulation in solid tumors may impede drug and immune cell access. PEGPH20 targets tumors that accumulate HA (HA-high). This study (NCT03267940) plans to enroll 70 subjects to evaluate the safety and activity of PEGPH20 + programmed cell death-ligand 1 (PD-L1) agent atezolizumab, (PEGCISGEMATEZO), & PEGPH20 + CISGEM (PEGCISGEM) in HA-high subjects with CCA and gallbladder cancer. Study will comprise initial run-in and expansion portions. Primary endpoints include incidence of AEs and other laboratory/safety parameters and ORR (RECIST v1.1). Secondary endpoints include PK parameters; DOR, DCR, PFS, and ORR (RECIST v1.1 and immune-modified RECIST); and OS and OS by PD-L1 expression. Methods: ~6 HA-high subjects will be enrolled in PEGCISGEM arm run-in portion and undergo at ≥1 cycle; subsequently, 6 HA-high subjects will enter the PEGCISGEMATEZO arm. Treatment period will be 21-day cycles. In the expansion portion, ~50 HA-high subjects will be enrolled and randomized in a 2:2:1 ratio into PEGCISGEMATEZO, PEGCISGEM, and CISGEM arms. PEGPH20 is planned to be administered at 3.0 μg/kg on Days 1, 8 and 15 of all cycles in both portions. ATEZO will be administered at 1200 mg 1–3 hours after PEGPH20 on Day 1 of each 21-day cycle in the PEGCISGEMATEZO arm in both portions. In the PEGCISGEM & PEGCISGEMATEZO arms, dosing schedule for CISGEM is the same during both portions, with administration of 25 mg/m2 CIS and 1000 mg/m2 GEM on Days 2 and 9 of each cycle. In CISGEM control arm (expansion only), dosing schedule will be on Days 1 and 8 of each cycle. Treatment will continue until death, withdrawal of consent, disease progression, or unacceptable toxicity. Tumor response will be evaluated using RECIST v1.1. AEs will be graded per NCI CTCAE v4.03. Tumor samples will be tested retrospectively for PD-L1 expression. Safety data will be periodically monitored by an independent data monitoring committee. Clinical trial information: NCT03267940.

TPS4142 Background: Advanced cholangiocarcinoma (CC) is a life-threatening disease for which there are limited therapeutic options. Mutations in isocitrate dehydrogenase 1 (mIDH1) occur in up to 25% of intrahepatic CC cases. mIDH1 lead to epigenetic and genetic changes that promote oncogenesis via production of the oncometabolite, D-2-hydroxyglutarate (2-HG). AG-120 is a first-in-class oral inhibitor of the mIDH1 enzyme, and is being tested in a phase 1 study that enrolled 73 patients (pts) with mIDH1 CC who had received a median of 2 prior therapies (range 1–5). AG-120 has demonstrated a favorable safety profile and clinical activity in this study. Among the 72 efficacy evaluable pts (≥1 post-baseline response assessment or discontinued prematurely), 6% (n = 4) had a confirmed partial response and 56% (n = 40) had stable disease. Progression-free survival (PFS) rate at 6 months was 40% as of Dec 16, 2016. The 500 mg once daily (QD) dose of AG-120 was selected for the ongoing phase 3 study in mIDH1 CC described here. Methods: ClarIDHy is a global, phase 3, multicenter, double-blind study randomizing 186 pts with mIDH1 CC in a 2:1 ratio to AG-120 (500 mg QD) or matched placebo (NCT02989857). Key eligibility criteria: nonresectable or metastatic CC; documented mIDH1 based on central laboratory testing; ECOG 0–1; measurable disease (RECIST v1.1); documented disease progression following ≤2 prior systemic therapies in the advanced setting, including at least 1 gemcitabine- or 5-fluorouracil-containing regimen; and no prior mIDH inhibitor therapy. Crossover from the placebo arm to the AG-120 arm will be permitted. The primary endpoint is PFS as assessed by an independent review. Secondary endpoints include safety, tolerability, overall response rate, overall survival, pharmacokinetic and pharmacodynamic analyses on plasma, and quality of life as assessed by the EORTC QLQ-C30, EORTC QLQ-BIL21, and EQ-5D-5L instruments. An independent data monitoring committee will monitor the data throughout the study. The ClarIDHy study is currently activated at participating sites in the US and will be activated in centers throughout Europe and in South Korea. Clinical trial information: NCT02989857.