Citations

e21057 Background: BRAF, NRAS, CDKN2A and P53 mutations are commonly observed pathogenic mutations in cutaneous melanoma. The influence of mutations such as BRAF, NRAS, CDKN2A and P53 on treatment response in the PD1 inhibitor era has not been well defined. Methods: This study included patients with melanoma with a cutaneous or unknown primary. All patients had genomic profiling with the Mayo Clinic 50-gene solid tumor mutation panel. Treatment response to first line immunotherapy with PD1, CTLA-4, or combination PD1/CTLA-4 inhibitors were assessed by response rate and time-to-progression (TTP) rate at 12 months. Each patient outcome was stratified by non-mutually exclusive gene mutation status into BRAF, NRAS, P53, CDKN2A, or quadruple negative (N4) groups. Results: Genomic profiling was performed on 208 patients, of whom 102 received first line immunotherapy. Most patients received a PD1 inhibitor (n = 62), followed by CTLA-4 inhibitor (n = 34), and combination therapy (n = 6). A trend towards improved outcomes was observed in CDKN2A and BRAF mutated patients with worse outcomes noted in P53, N4, and NRAS patients. The percent without progression at 12 months were BRAF 52.2%, CDKN2A 58.2%, NRAS 30.5%, P53 37.7%, and N4 26.7% (see table below). Response rates were BRAF 46.4%, CDKN2A 38.5%, NRAS 22.2%, P53 40.0%, and N4 33.3%. Conclusions: There is a trend towards improved outcomes with immunotherapy in BRAF and CDKN2A mutated patients while P53, NRAS and N4 patients have inferior outcomes. [Table: see text]

e15779 Background: There is paucity of data regarding the best available second-line treatment following progression on gemcitabine-based regimens in metastatic pancreatic ductal adenocarcinoma (PDAC). While a Nanoliposomal formulation of irinotecan (MM398) is considered a standard of care, there is conflicting data relating to the use of oxaliplatin in this setting. We performed a meta-analysis to determine the effectiveness of adding oxaliplatin (OX) or various irinotecan (IRI) formulations to a fluoropyrimidine (FP) as a second-line in PDAC patients. Methods: We searched different databases, including PubMed, Embase and Cochrane, to identify randomized controlled trials comparing FP monotherapy to FP combination therapy that includes either oxaliplatin (FPOX) or various irinotecan formulations (FPIRI) in PDAC patients who progressed after first-line treatment. Secondary analyses were planned to assess the effectiveness of FPOX and FPIRI compared to FP. Outcomes of interest included overall survival (OS) and progression-free survival (PFS). The overall effect was pooled using the DerSimonian and Laird random effects models. Results: Five studies (2 with FPIRI and 3 with FPOX) with 895 patients were identified. Patients randomized to FPIRI/FPOX had a significantly improved PFS (HR = 0.74, CI 0.62 to 0.89) and a trend towards an improved OS compared to FP monotherapy (HR = 0.88, CI 0.65 to 1.19). When comparing FPIRI to FP, there was an improvement in both PFS (HR = 0.64, CI 0.47 to 0.87) and OS (HR = 0.70, CI 0.55 to 0.89) in patients treated with the combination. Conversely, FPOX showed only a modest improvement in PFS (HR = 0.81, CI 0.67, 0.97) with no improvement in OS (HR = 1.03, CI 0.64 to 1.67). Conclusions: Combination chemotherapy with oxaliplatin or various irinotecan formulations seem to improve PFS vs. single agent FP. FPIRI, but not FPOX seem to confer an OS advantage. Oxaliplatin with FP following gemcitabine failure may need further confirmatory studies to establish its role in refractory pancreas cancer.

e15626 Background: FGFR2 fusions are found in 10-15% of intrahepatic cholangiocarcinomas. Individuals with FGFR2 fusions have a better prognosis and more indolent natural history. More recently FGFR2 fusions have been described as a predictive marker for tyrosine kinase inhibitors targeting the FGFR2 pathway. Texture analysis from CT imaging has been used in the past to estimate degree of fibrosis and angiogenesis in various tumors types; however, texture analysis has not been used in the past to detect FGFR2 rearrangements. Methods: This is a retrospective study of 33 patients with intrahepatic cholangiocarcinoma who were previously tested for FGFR2 fusions with either a FISH break apart assay or with clinically available next generation sequencing assays. All patients had a contrast enhanced CT performed. To address physiological and pathological variations, matched-size regions of interest (ROIs) over areas of non-necrotic tumor and unaffected liver during the portal venous phase were drawn. The paired ROIs for each patient were then processed via an imaging analytic pipeline for (1) ROI normalization, (2) texture panel creation, and (3) machine learning predictive model development. Results: Fifteen patients with FGFR2 fusions and 18 patients without FGFR2 fusions were included in the study. Using the developed predictive model, accurate FGFR2 fusion classification in 90% of cases was achieved (sensitivity = 87%, specificity = 94%). Conclusions: Utilizing advanced analytics with machine learning techniques, multi-textural data obtained from conventional CT images has the capability to detect genetic aberrations in intrahepatic cholangiocarcinoma, including FGFR2 gene fusions. Radiogenomic evaluation has several attractive benefits including the cost effective and expeditious detection of actionable mutations such as FGFR2 fusions as well as avoidance of invasive procedures such as percutaneous core biopsies. [Table: see text]

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.

4073 Background: Durvalumab and tremelimumab, investigational monoclonal antibodies against PD-L1 and CTLA-4 immune checkpoints, respectively, have shown efficacy in monotherapy and offer promise in combination for patients (pts) with HCC. This is a phase I/II, open-label, randomized study of durvalumab combined with tremelimumab in unresectable HCC. Methods: Phase I part of this study is a safety run-in cohort treated at the recommended phase II doses of the durvalumab/tremelimumab combination (20 and 1 mg/kg IV Q4W respectively for 4 doses followed by 20 mg/kg Q4W durvalumab alone) in pts with unresectable HCC with or without concomitant HBV or HCV infection who progress on, are intolerant to, or have refused sorafenib therapy. Secondary objectives include evaluation of antitumor activity. Here we present results of a preplanned analysis from the completed phase I part of the study. Results: As of 10 January 2017, 40 pts have been enrolled (11 HBV+, 9 HCV+, 20 uninfected). 30% had no prior systemic therapy; 93% were Child Pugh Class A. 24 (60%) had ≥1 treatment-related AE; 20% had ≥1 grade ≥3 related AE. Most common (≥15%) treatment-related AEs: fatigue (20%), increased ALT (18%), pruritus (18%), and increased AST (15%). Most common grade ≥3 related AE was asymptomatic increased AST (10%). 24 pts have discontinued treatment: 3 due to treatment-related AEs (grade 3 pneumonitis, grade 3 colitis/diarrhea, asymptomatic grade 4 elevated AST and ALT), 16 due to progressive disease, 4 due to death unrelated to treatment (cardiac arrest, variceal bleed, progressive disease, probable HCC rupture), and 1 other (pt entered hospice care). 40 pts were evaluable for response at ≥16 weeks follow-up. Conclusions: No unexpected safety signals with durvalumab and tremelimumab were seen in this unresectable HCC population. Clinical activity observed predominantly in uninfected pts though interpretation limited by small subsets. Enrollment to the phase II portion of the study is ongoing. Clinical trial information: NCT02519348. [Table: see text]

4018 Background: BTCs are often diagnosed at an advanced stage and have a poor prognosis. The standard therapy for aBTCs is the combination of GC. However, the median overall survival (mOS) is dismal at 11.7 months (mos) with a median progression free survival (mPFS) of 8 mos. Methods: A single arm, phase II study was conducted at MD Anderson and Mayo Clinic Arizona. Patients (pts) with aBTC were treated at initial dose level of G/C/N (in mg/m2) at 1000/25/125 (n = 27) which was reduced to lower doses due to grade 3/4 hematological (heme) toxicity (tox) - G/C/N: 800/25/100 (n = 33). Cycles were q21 days with restaging q3 cycles until progression. PFS was the primary endpoint (endpt). Using a Bayesian hypothesis test-based design, we assumed mPFS of 8 mos under the null hypothesis (H0), 10 mos under the alternative (H1). Secondary endpts included mOS, RECIST v1.1 response rate (RR), safety and CA19-9 response. Results: 60 pts were enrolled with data on 51 available as of the time of this abstract (age: median 60 yrs [range 31-77], ECOG PS 0/1 (17/34), M/F (30/21), intrahepatic cholangiocarcinoma/extrahepatic/gallbladder (32/8/11). Median follow-up was 11.5 mos and median number of treatment (trmt) cycles = 5. Pts at initial dose level had significant grade 3/4 heme tox: neutropenia, febrile neutropenia, anemia, and thrombocytopenia leading to trmt discontinuation in 6/27 pts. After dose reduction to G/C/N (in mg/m2) at 800/25/100, trmt was better tolerated with only 4 pts experiencing grade 4 heme tox. Non-heme tox were grade 3 in 10 pts: nausea/vomiting, diarrhea, thromboembolic event/CVA, hypokalemia, constipation, cystitis, LFT elevations. In the initial 51 pts, mPFS = 11.4 mos (95% CI: 6.1, not reached) and mOS not reached (estimated > 20 mos, 1-year survival rate 66.7%; 95%CI: 65.9-92.2%). 34 pts evaluable for response: disease control rate (PR+CR+SD)-82.3% and RR-32.3%. 3 unresectable cases were operated post trmt with 1 pathologic CR. Conclusions: The combination of GCN was well tolerated at adjusted doses and demonstrates encouraging preliminary efficacy having met its mPFS endpt and a 1-year survival rate higher than historical control. These results merit evaluating GC +/-N in a randomized controlled study. Clinical trial information: NCT02392637.

TPS4145 Background: Dysregulation of fibroblast growth factor receptor (FGFR) signaling by FGFR translocations and activating mutations is implicated in many cancers, including CCA. FGFR2 translocation, the most common FGFRalteration, occurs in ~13% of pts with intrahepatic CCA. INCB054828 is a novel, orally available, selective inhibitor of FGFR1, FGFR2, and FGFR3 tyrosine kinase activity (AACR 2015; Abstract 771). Methods: This phase 2, open-label trial will evaluate INCB054828 monotherapy in pts with advanced/metastatic or unresectable CCA (NCT02924376). Pts will be prescreened locally or centrally for FGF/FGFR status prior to enrollment (Table): FGFR2 translocation (Cohort A); other FGF/FGFR alteration (Cohort B); no FGF/FGFR alteration (Cohort C; negative control for effects of FGF/FGFR alteration on objective response rate [ORR]). Eligibility criteria include: age ≥18 years; ECOG performance status ≤2; adequate liver and renal function; life expectancy ≥12 wks; disease progression after ≥1 prior systemic therapy; no prior use of selective FGFR inhibitors. Pts will self-administer INCB054828 orally at a starting dose of 13.5 mg QD on a 21-day cycle (2 wks on; 1 wk off); treatment will continue until disease progression or unacceptable toxicity. The primary endpoint will be ORR (complete or partial response, independent radiologic review committee, RECIST v1.1) in pts with FGFR2 translocation (Cohort A). Secondary endpoints include ORR in pts positive or negative for any FGF/FGFRalteration and duration of response, PFS, OS, and safety (all cohorts). The study has currently enrolled 2 pts (recruitment ongoing; estimated primary completion, April 2018). Clinical trial information: NCT02924376. [Table: see text]