Revisiting the Malignant Masquerade at the Liver Hilum: Have We Made Progress?

BACKGROUND

Distinguishing malignant from benign causes of obstruction at the liver hilum can pose a diagnostic dilemma. This study aimed to determine factors that predict benign causes of hilar obstruction and long-term outcomes after resection.

METHODS

Consecutive patients who underwent surgery for hilar obstruction at a single institution between 1997 and 2022 were retrospectively analyzed. Median follow-up was 26 months (range 0-281 months).

RESULTS

Among 182 patients who underwent surgery for hilar obstruction, 25 (14%) patients were found to have benign disease. Median CA19-9 level after normalization of serum bilirubin was 80 U/mL (range 1-5779) and 21 U/mL (range 1-681) among patients with malignant and benign strictures, respectively (p = 0.001). Cross-sectional imaging features associated with malignancy were lobar atrophy, soft tissue mass/infiltration, and vascular involvement (all p < 0.05). Factors not correlated with malignancy were jaundice upon presentation, peak serum bilirubin, sex, and race. Preoperative bile duct brushing or biopsy had sensitivity and specificity rates of 82% and 55%, respectively. Among patients who underwent resection with curative intent, grade 3-4 complications occurred in 55% and 29% of patients with malignant and benign strictures, respectively (p = 0.028). Postoperative long-term complications of chronic portal hypertension and recurrent cholangitis occurred in ≥ 10% of patients with both benign and malignant disease (p = non-significant).

CONCLUSIONS

Strictures at the liver hilum continue to present diagnostic and management challenges. Postoperative complications and long-term sequelae of portal hypertension and recurrent cholangitis develop in a significant number of patients after resection of both benign and malignant strictures.

RAF inhibitor re-challenge therapy in BRAF-aberrant pan-cancers: the RE-RAFFLE study

Previous studies have shown the clinical benefit of rechallenging the RAF pathway in melanoma patients previously treated with BRAF inhibitors. 44 patients with multiple tumors harboring RAF alterations were rechallenged with a second RAF inhibitor, either as monotherapy or in combination with other therapies, after prior therapy with a first RAF inhibitor. This retrospective observational study results showed that rechallenging with RAFi(s) led to an overall response rate of 18.1% [PR in thyroid (1 anaplastic; 3 papillary), 1 ovarian, 2 melanoma, 1 cholangiocarcinoma, and 1 anaplastic astrocytoma]. The clinical benefit rate was 54.5%; more than 30% of patients had durable responses with PR and SD lasting > 6 months. The median progression-free survival on therapy with second RAF inhibitor in the rechallenge setting either as monotherapy or combination was shorter at 2.7 months (0.9-30.1 m) compared to 8.6 months (6.5-11.5 m) with RAF-1i. However, the median PFS with RAF-2i responders (PFS-2) improved at 12.8 months compared to 11.4 months with RAF-1i responders. The median OS from retreatment with RAF-2i was 15.5 months (11.1-30.8 m). Further prospective studies are needed to validate these results and expand targeted therapy options for RAF-aberrant cancers.

Comprehensive Immunogenomic Profiling of IDH1-/2-Altered Cholangiocarcinoma

PURPOSE

Isocitrate dehydrogenase (IDH)1/2 genomic alterations (GA) occur in 20% of intrahepatic cholangiocarcinoma (iCCA); however, the immunogenomic landscape of IDH1-/2-mutated iCCA is largely unknown.

METHODS

Comprehensive genomic profiling (CGP) was performed on 3,067 cases of advanced iCCA. Tumor mutational burden (TMB), PD-L1 expression (Dako 22C3), microsatellite instability (MSI), and genomic loss of heterozygosity (gLOH) as a surrogate marker for homologous recombination deficiency were examined. RNA sequencing of 73 patient samples was analyzed for differences in stromal/immune cell infiltration, immune marker expression, and T-cell inflammation. Tissue microarray arrays were subjected to multiplex immunohistochemistry and colocalization analysis in 100 surgical samples. Retrospective clinical data were collected for 501 patients with cholangiocarcinoma to examine median overall survival (mOS) in IDH1/2+ versus IDHwt.

RESULTS

Of 3,067 iCCA cases subjected to CGP, 426 (14%) were IDH1+ and 125 (4%) were IDH2+. IDH1 GA included R132C (69%) and R132L/G/S/H/F (16%/7%/4%/3%/<1%). IDH2 GA occurred at R172 (94.4%) and R140 (6.6%). No significant difference was seen in median gLOH between IDH1+ versus IDHwt iCCA (P = .37), although patterns of comutations differed. MSI-High (P = .009), TMB ≥10 mut/Mb (P < .0001), and PD-L1 positivity were lower in IDH1/2+ versus IDHwt iCCA. Resting natural killer cell population, CD70, and programmed cell death 1 expression were significantly higher in non-IDH1-mutated cases, whereas V-set domain containing T-cell activation inhibitor 1 (B7-H4) expression was significantly higher in IDH1+. No significant difference in mOS was observed between IDH1/2+ versus IDHwt patients.

CONCLUSION

Significant differences in GA and immune biomarkers are noted between IDH1/2+ and IDHwt iCCA. IDH1-/2-mutated tumors appear immunologically cold without gLOH. These immunogenomic data provide insight for precision targeting of iCCA with IDH alterations.

Co-Clinical Trial of Novel Bispecific Anti-HER2 Antibody Zanidatamab in Patient-Derived Xenografts

Zanidatamab is a bispecific HER2-targeted antibody which has demonstrated antitumor activity in a broad range of HER2 amplified/expressing solid tumors. We determined the antitumor activity of zanidatamab in patient-derived xenograft (PDX) models developed from pre-treatment or post-progression biopsies on the first-in-human zanidatamab phase I study (NCT02892123). Of 36 tumors implanted, 19 PDX models were established (52.7% take rate) from 17 patients. Established PDXs represented a broad range of HER2-expressing cancers, and in vivo testing demonstrated an association between antitumor activity in PDXs and matched patients in 7 of 8 co-clinical models tested. We also identified amplification of MET as a potential mechanism of acquired resistance to zanidatamab and demonstrated that MET inhibitors have single agent activity and can enhance zanidatamab activity in vitro and in vivo. These findings provide evidence that PDXs can be developed from pre-treatment biopsies in clinical trials and may provide insight into mechanisms of resistance.

Methylthioadenosine Phosphorylase Genomic Loss in Advanced Gastrointestinal Cancers

BACKGROUND

One of the most common sporadic homozygous deletions in cancers is 9p21 loss, which includes the genes methylthioadenosine phosphorylase (MTAP), CDKN2A, and CDKN2B, and has been correlated with worsened outcomes and immunotherapy resistance. MTAP-loss is a developing drug target through synthetic lethality with MAT2A and PMRT5 inhibitors. The purpose of this study is to investigate the prevalence and genomic landscape of MTAP-loss in advanced gastrointestinal (GI) tumors and investigate its role as a prognostic biomarker.

MATERIALS AND METHODS

We performed next-generation sequencing and comparative genomic and clinical analysis on an extensive cohort of 64 860 tumors comprising 5 GI cancers. We compared the clinical outcomes of patients with GI cancer harboring MTAP-loss and MTAP-intact tumors in a retrospective study.

RESULTS

The prevalence of MTAP-loss in GI cancers is 8.30%. MTAP-loss was most prevalent in pancreatic ductal adenocarcinoma (PDAC) at 21.7% and least in colorectal carcinoma (CRC) at 1.1%. MTAP-loss tumors were more prevalent in East Asian patients with PDAC (4.4% vs 3.2%, P = .005) or intrahepatic cholangiocarcinoma (IHCC; 6.4% vs 4.3%, P = .036). Significant differences in the prevalence of potentially targetable genomic alterations (ATM, BRAF, BRCA2, ERBB2, IDH1, PIK3CA, and PTEN) were observed in MTAP-loss tumors and varied according to tumor type. MTAP-loss PDAC, IHCC, and CRC had a lower prevalence of microsatellite instability or elevated tumor mutational burden. Positive PD-L1 tumor cell expression was less frequent among MTAP-loss versus MTAP-intact IHCC tumors (23.2% vs 31.2%, P = .017).

CONCLUSION

In GI cancers, MTAP-loss occurs as part of 9p21 loss and has an overall prevalence of 8%. MTAP-loss occurs in 22% of PDAC, 15% of IHCC, 8.7% of gastroesophageal adenocarcinoma, 2.4% of hepatocellular carcinoma, and 1.1% of CRC and is not mutually exclusive with other targetable mutations.

Efficacy and safety of autologous tumor-infiltrating lymphocytes in recurrent or refractory ovarian cancer, colorectal cancer, and pancreatic ductal adenocarcinoma

BACKGROUND

Tumor-infiltrating lymphocyte (TIL) therapy has shown efficacy in metastatic melanoma, non-small cell lung cancer, and other solid tumors. Our preclinical work demonstrated more robust CD8 predominant TIL production when agonistic anti-4-1BB and CD3 antibodies were used in early ex vivo TIL culture.

METHODS

Patients with treatment-refractory metastatic colorectal (CRC), pancreatic (PDAC) and ovarian (OVCA) cancers were eligible. Lymphodepleting chemotherapy was followed by infusion of ex vivo expanded TIL, manufactured at MD Anderson Cancer Center with IL-2 and agonistic stimulation of CD3 and 4-1BB (urelumab). Patients received up to six doses of high-dose IL-2 after TIL infusion. Primary endpoint was evaluation of objective response rate at 12 weeks using Response Evaluation Criteria in Solid Tumors version 1.1 with secondary endpoints including disease control rate (DCR), duration of response, progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

17 patients underwent TIL harvest and 16 were treated on protocol (NCT03610490), including 8 CRC, 5 PDAC, and 3 OVCA patients. Median age was 57.5 (range 33-70) and 50% were females. Median number of lines of prior therapy was 2 (range 1-8). No responses were observed at 12 weeks. Ten subjects achieved at least one stable disease (SD) assessment for a DCR of 62.5% (95% CI 35.4% to 84.8%). Best response included prolonged SD in a patient with PDAC lasting 17 months. Median PFS and OS across cohorts were 2.53 months (95% CI 1.54 to 4.11) and 18.86 months (95% CI 4.86 to NR), respectively. Grade 3 or higher toxicities attributable to therapy were seen in 14 subjects (87.5%; 95% CI 61.7% to 98.4%). Infusion product analysis showed the presence of effector memory cells with high expression of CD39 irrespective of tumor type and low expression of checkpoint markers.

CONCLUSIONS

TIL manufactured with assistance of 4-1BB and CD3 agonism is feasible and treatment is associated with no new safety signals. While no responses were observed, a significant portion of patients achieved SD suggesting early/partial immunological effect. Further research is required to identify factors associated with resistance and functionally enhance T cells for a more effective therapy.

Limited Independent Follow-Up with Germline Testing of Variants Detected in BRCA1 and BRCA2 by Tumor-Only Sequencing

Introduction

Genomic profiling is performed in patients with advanced or metastatic cancer, in order to direct cancer treatment, often sequencing tumor-only, without a matched germline comparator. However, because many of the genes analyzed on tumor profiling overlap with those known to be associated with hereditary cancer predisposition syndromes (HCPS), tumor-only profiling can unknowingly uncover germline pathogenic (P) and likely pathogenic variants (LPV). In this study, we evaluated the number of patients with P/LPVs identified in BRCA1 and BRCA2 (BRCA1/2) via tumor-only profiling, then determined the germline testing outcomes for those patients.

Methods

A retrospective chart review was performed to identify patients with BRCA1/2 variants on tumor-only genomic profiling, and whether they had germline testing.

Results

This study found that of 2923 patients with 36 tumor types who underwent tumor-only testing, 554 had a variant in BRCA1/2 (19.0%); 119 of the 554 patients (21.5%) had a P/LP BRCA1/2 variant, representing 4.1% of the overall population who underwent genomic profiling. Seventy-three (61.3%) of 119 patients with BRCA1/2 P/LPV on tumor-only testing did not undergo germline testing, 34 (28.6%) had already had germline testing before tumor-only testing, and 12 (10.1%) underwent germline testing after tumor-only testing. Twenty-eight germline BRCA1/2 P/LPVs were detected, 24 in those who had prior germline testing, and 4 among the 12 patients who had germline testing after tumor-only testing.

Conclusion

Tumor-only testing is likely to identify P/LPVs in BRCA1/2. Efforts to improve follow-up germline testing is needed to improve identification of germline BRCA1/2 alterations.

Convergent MAPK pathway alterations mediate acquired resistance to FGFR inhibitors in FGFR2 fusion-positive cholangiocarcinoma

BACKGROUND & AIMS

There is a knowledge gap in understanding mechanisms of resistance to fibroblast growth factor receptor (FGFR) inhibitors (FGFRi) and a need for novel therapeutic strategies to overcome it. We investigated mechanisms of acquired resistance to FGFRi in patients with FGFR2-fusion-positive cholangiocarcinoma (CCA).

METHODS

A retrospective analysis of patients who received FGFRi therapy and underwent tumor and/or cell-free DNA analysis, before and after treatment, was performed. Longitudinal circulating tumor DNA samples from a cohort of patients in the phase I trial of futibatinib (NCT02052778) were assessed. FGFR2-BICC1 fusion cell lines were developed and secondary acquired resistance mutations in the mitogen-activated protein kinase (MAPK) pathway were introduced to assess their effect on sensitivity to FGFRi in vitro.

RESULTS

On retrospective analysis of 17 patients with repeat sequencing following FGFRi treatment, new FGFR2 mutations were detected in 11 (64.7%) and new alterations in MAPK pathway genes in nine (52.9%) patients, with seven (41.2%) patients developing new alterations in both the FGFR2 and MAPK pathways. In serially collected plasma samples, a patient treated with an irreversible FGFRi tested positive for previously undetected BRAF V600E, NRAS Q61K, NRAS G12C, NRAS G13D and KRAS G12K mutations upon progression. Introduction of a FGFR2-BICC1 fusion into biliary tract cells in vitro sensitized the cells to FGFRi, while concomitant KRAS G12D or BRAF V600E conferred resistance. MEK inhibition was synergistic with FGFRi in vitro. In an in vivo animal model, the combination had antitumor activity in FGFR2 fusions but was not able to overcome KRAS-mediated FGFRi resistance.

CONCLUSIONS

These findings suggest convergent genomic evolution in the MAPK pathway may be a potential mechanism of acquired resistance to FGFRi.

CLINICAL TRIAL NUMBER

NCT02052778.

IMPACT AND IMPLICATIONS

We evaluated tumors and plasma from patients who previously received inhibitors of fibroblast growth factor receptor (FGFR), an important receptor that plays a role in cancer cell growth, especially in tumors with abnormalities in this gene, such as FGFR fusions, where the FGFR gene is fused to another gene, leading to activation of cancer cell growth. We found that patients treated with FGFR inhibitors may develop mutations in other genes such as KRAS, and this can confer resistance to FGFR inhibitors. These findings have several implications for patients with FGFR2 fusion-positive tumors and provide mechanistic insight into emerging MAPK pathway alterations which may serve as a therapeutic vulnerability in the setting of acquired resistance to FGFRi.

CRISPR screening identifies BET and mTOR inhibitor synergy in cholangiocarcinoma through serine glycine one carbon

Patients with cholangiocarcinoma have poor clinical outcomes due to late diagnoses, poor prognoses, and limited treatment strategies. To identify drug combinations for this disease, we have conducted a genome-wide CRISPR screen anchored on the bromodomain and extraterminal domain (BET) PROTAC degrader ARV825, from which we identified anticancer synergy when combined with genetic ablation of members of the mTOR pathway. This combination effect was validated using multiple pharmacological BET and mTOR inhibitors, accompanied by increased levels of apoptosis and cell cycle arrest. In a xenograft model, combined BET degradation and mTOR inhibition induced tumor regression. Mechanistically, the 2 inhibitor classes converged on H3K27ac-marked epigenetic suppression of the serine glycine one carbon (SGOC) metabolism pathway, including the key enzymes PHGDH and PSAT1. Knockdown of PSAT1 was sufficient to replicate synergy with single-agent inhibition of either BET or mTOR. Our results tie together epigenetic regulation, metabolism, and apoptosis induction as key therapeutic targets for further exploration in this underserved disease.

Comparative Genomic Analysis and Clinical Outcomes of BRAF-mutated Advanced Biliary Tract Cancers

PURPOSE

BRAF mutations are rare in biliary tract cancers (BTC), but are of interest given the recent developments in targeted therapy for BTC. We investigated the clinical outcomes in a cohort of BRAF-mutant advanced BTC treated with first-line chemotherapy. Furthermore, we investigated the genomic landscape of BRAF class I, II, and III mutations in the intrahepatic cholangiocarcinoma (iCCA) subgroup of BTC.

EXPERIMENTAL DESIGN

We analyzed two nonoverlapping cohorts. We examined the genomic landscape of BRAF-mutated iCCA in a "genomic cohort" [187 class I, 82 class II, 113 class III BRAF mutants and 8,026 wildtype (WT)]. We also analyzed median progression-free survival (PFS) and overall survival (OS) on first-line chemotherapy in a separate multi-institutional "clinical cohort" of patients with BTC (including iCCA and extrahepatic cholangiocarcinoma (eCCA) and gallbladder cancer; 41 class I, 32 class II+III BRAF mutants and 1,042 WT).

RESULTS

In the entire BTC clinical cohort, the median PFS was shorter for class I [HR, 2.11 (P < 0.001)] and class II+III [HR, 1.72 (P = 0.007)] as compared with BRAF WT. OS was also shorter in class I [HR, 2.04 (P = 0.011)] and class II+III [HR, 1.86 (P = 0.002)] as compared with BRAF WT. In the iCCA subgroup, class I alterations were mutually exclusive with FGFR2, IDH1/2, ERBB2, and KRAS mutations. Class II+III mutations appear to be mutually exclusive with FGFR2 and KRAS.

CONCLUSIONS

In BTC, all classes of BRAF mutations are associated with a worse prognosis. BRAF mutations occur in 5% of iCCA subgroup and may be mutually exclusive with other targetable mutations.

Futibatinib, an Irreversible FGFR1-4 Inhibitor for the Treatment of FGFR-Aberrant Tumors

Fibroblast growth factor receptors (FGFR) are emerging as an important therapeutic target for patients with advanced, refractory cancers. Most selective FGFR inhibitors under investigation show reversible binding, and their activity is limited by acquired drug resistance. This review summarizes the preclinical and clinical development of futibatinib, an irreversible FGFR1-4 inhibitor. Futibatinib stands out among FGFR inhibitors because of its covalent binding mechanism and low susceptibility to acquired resistance. Preclinical data indicated robust activity of futibatinib against acquired resistance mutations in the FGFR kinase domain. In early-phase studies, futibatinib showed activity in cholangiocarcinoma, and gastric, urothelial, breast, central nervous system, and head and neck cancers harboring various FGFR aberrations. Exploratory analyses indicated clinical benefit with futibatinib after prior FGFR inhibitor use. In a pivotal phase II trial, futibatinib demonstrated durable objective responses (42% objective response rate) and tolerability in previously treated patients with advanced intrahepatic cholangiocarcinoma harboring FGFR2 fusions or rearrangements. A manageable safety profile was observed across studies, and patient quality of life was maintained with futibatinib treatment in patients with cholangiocarcinoma. Hyperphosphatemia, the most common adverse event with futibatinib, was well managed and did not lead to treatment discontinuation. These data show clinically meaningful benefit with futibatinib in FGFR2-rearrangement-positive cholangiocarcinoma and provide support for further investigation of futibatinib across other indications. Future directions for this agent include elucidating mechanisms of resistance and exploration of combination therapy approaches.

Independent of Primary Sclerosing Cholangitis and Cirrhosis, Early Adulthood Obesity Is Associated with Cholangiocarcinoma

BACKGROUND

It is estimated that 6% to 20% of all cholangiocarcinoma (CCA) diagnoses are explained by primary sclerosing cholangitis (PSC), but the underlying risk factors in the absence of PSC are unclear. We examined associations of different risk factors with intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC) in the United States.

METHODS

We conducted a case-control study of 121 patients with ECC and 308 patients with ICC treated at MD Anderson Cancer Center between May 2014 and March 2020, compared with 1,061 healthy controls. Multivariable logistic regression analysis was applied to estimate the adjusted OR (AOR) and 95% confidence interval (CI) for each risk factor.

RESULTS

Being Asian, diabetes mellitus, family history of cancer, and gallbladder stones were associated with higher odds of developing ICC and ECC. Each 1-unit increase in body mass index in early adulthood (ages 20-40 years) was associated with a decrease in age at diagnosis of CCA (6.7 months, P < 0.001; 6.1 months for ICC, P = 0.001; 8.2 months for ECC, P = 0.007). A family history of cancer was significantly associated with the risk of ICC and ECC development; the AORs (95% CI) were 1.11 (1.06-1.48) and 1.32 (1.01-2.00) for ICC and ECC, respectively.

CONCLUSIONS

In this study, early adulthood onset of obesity was significantly associated with CCA and may predict early diagnosis at younger age than normal weight individuals.

IMPACT

The study highlights the association between obesity and CCA, independent of PSC. There is a need to consider the mechanistic pathways of obesity in the absence of fatty liver and cirrhosis.

Enhancement Patterns of Metastatic Intrahepatic Cholangiocarcinoma and Outcomes after Chemotherapy and Radiation

PURPOSE/OBJECTIVE(S)

Patients with metastatic intrahepatic cholangiocarcinoma (M1-iCCA) have a poor prognosis with a 5-year survival rate of less than 20%. Definitive doses of radiation therapy (RT) after upfront chemotherapy (chemo/RT) in this patient population have shown to prolong survival by reducing the risk of tumor-related liver failure compared to chemotherapy alone. Our group has also identified a baseline radiographic feature, the arterial enhancement pattern, which has pathological and prognostic associations for iCCA. We tested the hypothesis that baseline arterial enhancement is independently associated with survival outcomes for patients who receive chemo/RT or chemo alone.

MATERIALS/METHODS

Patients with M1-iCCA from 2010 to 2021 were included in this retrospective study. Patients were grouped into those who underwent chemo alone and those who underwent chemo/RT. The inclusion criteria included confirmed diagnosis of M1-iCCA, availability of baseline multi-phasic computed tomography (CT), and follow-up for at least six months or until death. Tumor arterial enhancement patterns were categorized as previously described into hypovascular or hypervascular, where the tumors that were hypervascular had either peripheral enhancement or central enhancement. Mean tumor density in Hounsfield units was recorded for each patient. Survival was estimated using the Kaplan Meier method, and Cox proportional models were used to adjust for prognostic variables.

RESULTS

A total of 281 patients with iCCA were identified and 229 had evaluable CT scans. Demographic and baseline characteristics of patient groups are shown in the Table. On univariate analysis, patient age, ECOG performance status (PS) at diagnosis, treatment type, and arterial enhancement patterns associated with overall survival (OS). On multivariable analysis, the arterial enhancement pattern independently associated with OS after accounting for covariates. Patients with hypervascular tumors had prolonged OS compared to those with hypovascular tumors (HR = 0.72, [0.54 - 0.96], p = 0.02). Prolonged OS was also observed in the chemo/RT group compared to the chemo alone group (HR = 0.37, [0.25-0.54], p< 0.0001).

CONCLUSION

Baseline enhancement patterns of M1-iCCA were prognostic in the contexts of chemo alone and chemo/RT. This imaging-based biomarker may improve the ability to stratify patients for therapeutic management.

What Role Does Radiotherapy Play in the Molecular Era for Intrahepatic Cholangiocarcinoma?

ABSTRACT

Intrahepatic cholangiocarcinoma is a rare disease, yet with rising incidence globally. Most patients are not eligible for potentially curative surgical resection, and many patients with unresectable disease die within 12 months of diagnosis, primarily due to liver failure from the primary tumor. Recent prospective and retrospective studies indicate that local control of the primary tumor can be achieved with hypofractionated radiotherapy in patients with unresectable disease, translating into prolonged survival of these patients. During the time that these encouraging reports for radiotherapy have been published, numerous concurrent studies have also shown that intrahepatic cholangiocarcinoma is a molecularly diverse disease with multiple targetable genetic alterations and a complex tumor microenvironment. These biological insights have translated into new drug approvals for subsets of patients. We review the current knowledge about the biology and targeted treatment of intrahepatic cholangiocarcinoma and describe these developments in the context of modern radiotherapy.

Definitive Liver Radiotherapy for Intrahepatic Cholangiocarcinoma with Extrahepatic Metastases

Introduction

Tumor-related liver failure (TRLF) is the most common cause of death in patients with intrahepatic cholangiocarcinoma (ICC). Though we previously showed that liver radiotherapy (L-RT) for locally advanced ICC is associated with less frequent TRLF and longer overall survival (OS), the role of L-RT for patients with extrahepatic metastatic disease (M1) remains undefined. We sought to compare outcomes for M1 ICC patients treated with and without L-RT.

Methods

We reviewed ICC patients that found to have M1 disease at initial diagnosis at a single institution between 2010 and 2021 who received L-RT, matching them with an institutional cohort by propensity score and a National Cancer Database (NCDB) cohort by frequency technique. The median biologically effective dose was 97.5 Gy (interquartile range 80.5-97.9 Gy) for L-RT. Patients treated with other local therapies or supportive care alone were excluded. We analyzed survival with Cox proportional hazard modeling.

Results

We identified 61 patients who received L-RT and 220 who received chemotherapy alone. At median follow-up of 11 months after diagnosis, median OS was 9 months (95% confidence interval [CI] 8-11) and 21 months (CI: 17-26) for patients receiving chemotherapy alone and L-RT, respectively. TRLF was the cause of death more often in the patients who received chemotherapy alone compared to those who received L-RT (82% vs. 47%; p = 0.001). On multivariable propensity score-matched analysis, associations with lower risk of death included duration of upfront chemotherapy (hazard ratio [HR] 0.82; p = 0.005) and receipt of L-RT (HR: 0.40; p = 0.002). The median OS from diagnosis for NCDB chemotherapy alone cohort was shorter than that of the institutional L-RT cohort (9 vs. 22 months; p < 0.001).

Conclusion

For M1 ICC, L-RT associated with a lower rate of death due to TRLF and longer OS versus those treated with chemotherapy alone. Prospective studies of L-RT in this setting are warranted.

Abstract 963: Clinical impact of MTAP status in advanced cholangiocarcinoma: Genomic profile and response to treatment

Background: MTAP-loss is an emerging biomarker guiding druggable targets in cholangiocarcinoma and almost exclusively occurs in the setting of 9p21 loss, which has itself been associated with reduced IO responsiveness and poorer survival outcomes on a pan-cancer analysis. We sought to understand the clinical impact of MTAP status on treatment and survival outcomes, in a clinical cohort of molecularly characterized advanced cholangiocarcinoma patients.

Methods: We analyzed advanced cholangiocarcinoma patients treated and evaluated at MD Anderson Cancer Center, tested for MTAP. Clinical information including genomic co-alterations, demographic information, treatment history and response to treatment were retrieved from retrospective medical record review. Comprehensive genomic profiling was performed with FDA-approved assays. Statistical analysis was performed with SPSS24 using Fisher's exact test, multivariate Cox regression and Kaplan-Meyer method for survival analysis.

Results: 71 patients were identified (MTAP loss 31% (22/71); MTAP intact 69% (49/71)); 54,9% (39/71) were females. No significant difference in gender, age or ethnicity was seen between MTAP cohorts.

We found that altered CDKN2A (p&lt;0.01), CDKN2B (p&lt;0.01), and IDH1 (p=0.048) were highly correlated with MTAP loss, while STK11 (p=0.095), a prognostic indicator of IO resistance, also showed a tendency to be a surrogate marker of MTAP loss status. Tumor mutational burden (TMB) was lower in MTAP loss group (2.18 vs. 4.88, p &lt;0.01), but no difference was found in microsatellite instability (MSI) or PD-L1 status between groups.

On multivariate analysis, patients harboring CDKN2A loss were noted to have worse OS compared to those without CDKN2A intact (18.6 vs 29.9 months, 95% CI, p=0.035). No statistically significant difference in OS was observed by MTAP status (25.9 vs. 29.2 months, 95% CI, p=0.168). Other genomic alterations with significant impact on OS were CCNE1 (p&lt;0.01), FGF19 (p=0.04), and MYC (p=0.043).

Treatment with chemotherapy regimens containing Gemcitabine in the first line setting of metastatic disease showed higher disease control rate in the MTAP intact cohort (91.4%) vs. MTAP loss cohort (38.5%) (p&lt;0.01), but no statistically significant difference in response (PR/CR) (p=0.421). Few patients (14/71) received IO in this cohort; no significant difference in IO response was observed by MTAP status (p=0.152).

Conclusions: MTAP loss cholangiocarcinoma has a distinct molecular profile compared with MTAP intact including key differences in co-altered tumor suppressor genes and TMB. To our knowledge, this is the first real-world data describing the clinical and genomic differences in advanced cholangiocarcinoma by MTAP status. Further prospective data are required to validate these

findings.

Citation Format: Cátia F. Gaspar, Natalie Y. Ngoi, Tin Tang, Jeffrey Ross, Dean Pavlick, Gregory Buchold, Shubham Pant, Milind Javle, Jordi Ahnert. Clinical impact of MTAP status in advanced cholangiocarcinoma: Genomic profile and response to treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 963.

Immune Checkpoint Inhibitors for Solid Tumors in the Adjuvant Setting: Current Progress, Future Directions, and Role in Transplant Oncology

The rationale for administering immune checkpoint inhibitors (ICIs) in the adjuvant setting is to eradicate micro-metastases and, ultimately, prolong survival. Thus far, clinical trials have demonstrated that 1-year adjuvant courses of ICIs reduce the risk of recurrence in melanoma, urothelial cancer, renal cell carcinoma, non-small cell lung cancer, and esophageal and gastroesophageal junction cancers. Overall survival benefit has been shown in melanoma while survival data are still not mature in other malignancies. Emerging data also show the feasibility of utilizing ICIs in the peri-transplant setting for hepatobiliary malignancies. While ICIs are generally well-tolerated, the development of chronic immune-related adverse events, typically endocrinopathies or neurotoxicities, as well as delayed immune-related adverse events, warrants further scrutiny regarding the optimal duration of adjuvant therapy and requires a thorough risk-benefit determination. The advent of blood-based, dynamic biomarkers such as circulating tumor DNA (ctDNA) can help detect minimal residual disease and identify the subset of patients who would likely benefit from adjuvant treatment. In addition, the characterization of tumor-infiltrating lymphocytes, neutrophil-to-lymphocyte ratio, and ctDNA-adjusted blood tumor mutation burden (bTMB) has also shown promise in predicting response to immunotherapy. Until additional, prospective studies delineate the magnitude of overall survival benefit and validate the use of predictive biomarkers, a tailored, patient-centered approach to adjuvant ICIs that includes extensive patient counseling on potentially irreversible adverse effects should be routinely incorporated into clinical practice.

BRAF v600E-mutant cancers treated with vemurafenib alone or in combination with everolimus, sorafenib, or crizotinib or with paclitaxel and carboplatin (VEM-PLUS) study

Combined BRAF + MEK inhibition is FDA approved for BRAF V600E-mutant solid tumors except for colorectal cancer. However, beyond MAPK mediated resistance several other mechanisms of resistance such as activation of CRAF, ARAF, MET, P13K/AKT/mTOR pathway exist among other complex pathways. In the VEM-PLUS study, we performed a pooled analysis of four phase one studies evaluating the safety and efficacy of vemurafenib monotherapy and vemurafenib combined with targeted therapies (sorafenib, crizotinib, or everolimus) or carboplatin plus paclitaxel in advanced solid tumors harboring BRAF V600 mutations. When vemurafenib monotherapy was compared with the combination regimens, no significant differences in OS or PFS durations were noted, except for inferior OS in the vemurafenib and paclitaxel and carboplatin trial (P = 0.011; HR, 2.4; 95% CI, 1.22-4.7) and in crossover patients (P = 0.0025; HR, 2.089; 95% CI, 1.2-3.4). Patients naïve to prior BRAF inhibitors had statistically significantly improved OS at 12.6 months compared to 10.4 months in the BRAF therapy refractory group (P = 0.024; HR, 1.69; 95% CI 1.07-2.68). The median PFS was statistically significant between both groups, with 7 months in the BRAF therapy naïve group compared to 4.7 months in the BRAF therapy refractory group (P = 0.016; HR, 1.80; 95% CI 1.11-2.91). The confirmed ORR in the vemurafenib monotherapy trial (28%) was higher than that in the combination trials. Our findings suggest that, compared with vemurafenib monotherapy, combinations of vemurafenib with cytotoxic chemotherapy or with RAF- or mTOR-targeting agents do not significantly extend the OS or PFS of patients who have solid tumors with BRAF V600E mutations. Gaining a better understanding of the molecular mechanisms of BRAF inhibitor resistance, balancing toxicity and efficacy with novel trial designs are warranted.

Brain Metastases from Biliary Tract Cancer: Case Series and Clinicogenomic Analysis

BACKGROUND

Limited data from small series have suggested that brain metastases from biliary tract cancers (BrM-BTC) affect ≤2% of patients with BTC. We sought to review our experience with patients with BrM-BTC and to identify associations of tumor-related molecular alterations with outcomes.

MATERIALS AND METHODS

A retrospective review of patients with BTC seen at a tertiary referral center from 2005 to 2021 was performed; patients with BrM-BTC were identified, and clinical and molecular data were collected.

RESULTS

Twenty-one of 823 patients with BTC (2.6%) developed BrM. For patients with BrM-BTC, median follow-up time was 27.9 months after primary BTC diagnosis and 3.1 months after BrM diagnosis. Median time from primary diagnosis to diagnosis of BrM was 14.4 [range, 1.1-66.0] months. Median overall survival (OS) from primary diagnosis was 31.5 [2.9-99.8] months and median OS from BrM diagnosis was 4.2 [0.2-33.8] months. Patients who underwent BrM-directed therapy trended toward longer OS following BrM diagnosis than patients receiving supportive care only (median 6.5 vs 0.8 months, P = .060). The BrM-BTC cohort was enriched for BRAF (30%), PIK3CA (25%), and GNAS (20%) mutations. patients with BrM-BTC with BRAF mutations trended toward longer OS following BrM diagnosis (median 13.1 vs 4.2 months, P = .131).

CONCLUSION

This is the largest series of patients with BrM-BTC to date and provides molecular characterization of this rare subgroup of patients with BTC. Patients with BrM-BTC may be more likely to have BRAF mutations. With advances in targeted therapy for patients with BTC with actionable mutations, continued examination of shifting patterns of failure, with emphasis on BrM, is warranted.

Neoadjuvant chemotherapy for high-risk intrahepatic cholangiocarcinoma - does pathologic response mean better outcomes?

BACKGROUND

The role of neoadjuvant chemotherapy (NAC) in the management of intrahepatic cholangiocarcinoma (ICC) remains unknown. We sought to evaluate our experience treating high-risk ICC with NAC and to determine the prognostic significance of pathologic response.

METHODS

Patients with ICC treated with NAC and surgery were analyzed using a prospectively maintained database. Pathologic response was graded by a blinded pathologist. Clinicopathologic/treatment variables were evaluated for associations with survival.

RESULTS

Among 45 patients who received NAC followed by hepatectomy for high-risk ICC, 32(71%) were considered stage III, and 6(13%) were considered stage IV at time of diagnosis. Major response was identified in 39% of cases, including 2 with pathologic complete response. Patients with major response had a longer median NAC duration than patients with minor response (6 vs 4cycles, P=0.02). Regimen (gemcitabine/cisplatin vs gemcitabine/cisplatin/nab-paclitaxel) was not associated with response rate. Median recurrence-free (RFS) and overall survival (OS) were 11 and 45 months. Pathologic response was not associated with improved survival.

CONCLUSION

Pathologic response to NAC was not associated with survival in this highly selected cohort. Nonetheless, the extended OS experienced by these high-risk patients is encouraging and suggests that NAC may help select patients who stand to benefit from aggressive resection.

Palliative Rehabilitation in Acute Inpatient Rehabilitation: Prognostic Factors and Functional Outcomes in Patients with Cancer

BACKGROUND

Prognosis has a vital role for patients with cancer undergoing palliative rehabilitation in acute inpatient rehabilitation. This study aimed to identify the proportion of patients who survived <2 months after discharge and the associated prognostic factors.

MATERIALS AND METHODS

This was a secondary analysis of a retrospective study of 163 consecutive patients admitted to acute inpatient rehabilitation from September 1, 2017, to February 28, 2018 at a cancer center. Baseline demographics, clinical characteristics, and putative prognostic factors, including Activity Measure for Post-Acute Care (AM-PAC) functional scores, were analyzed.

RESULTS

Of 163 patients, 27 (17%; 95% CI, 11-23) died within 60 days of discharge. These patients were more likely to be male (OR = 2.83; 95% CI, 1.16-6.92; P = .017); have longer hospital stays (OR = 1.02; 95% CI, 1-1.04; P = .015); receive ≥ weekly packed red blood cell (OR = 5.31; 95% CI, 1.86-15.1; P = .003) or platelet (OR = 4.57; 95% CI, 1.44-14.5; P = .014) transfusions; have lower AM-PAC daily activity scores upon discharge (OR = 0.90; 95% CI, 0.83-0.97; P = .006); and have lower AM-PAC basic mobility scores upon admission (OR = 0.91; 95% CI, 0.85-0.98; P = .018) and discharge (OR = 0.88; 95% CI, 0.82-0.94; P = <.001). Multivariate analysis showed that the male sex (OR = 2.71; 95% CI, 1.03-7.15; P = .037) was independently associated with ≤2 months survival, whereas AM-PAC basic mobility score at admission of >33 (OR = 0.24, 95% CI, 0.07-0.79; P = .022) was less likely.

CONCLUSION

Approximately 1 in 6 patients who completed acute inpatient rehabilitation died within 2 months of discharge, had poorer baseline functional status, and were less likely to regain function than those who lived longer.

Nab-Paclitaxel, Capecitabine, and Radiation Therapy After Induction Chemotherapy in Treating Patients With Locally Advanced and Borderline Resectable Pancreatic Cancer: Phase 1 Trial and Imaging-based Biomarker Validation

PURPOSE

Effective consolidative chemoradiation (CRT) regimens are lacking. In this phase 1 trial, we evaluated the safety and efficacy of nab-paclitaxel, capecitabine, and radiation therapy after induction chemotherapy in patients with locally advanced and borderline-resectable pancreatic cancer (LAPC and BRPC). Also, we evaluated a computed tomography (CT)-based biomarker of response.

METHODS AND MATERIALS

Eligible patients had pathologically confirmed pancreatic ductal adenocarcinoma, underwent computed tomography-imaging, received a diagnosis of LAPC or BRPC, and received induction chemotherapy. Standard 3 + 3 study design was used, with 3 escalating nab-paclitaxel dose levels (50, 75, and 100 mg/m²) with concurrent capecitabine and RT in cohort sizes of 3 starting at the lowest dose. Dose limiting toxicity was defined as grade 3 or higher toxicity. Patients were restaged 4 to 6 weeks post-CRT completion, and surgical resection was offered to those with stable/responsive disease. We scored the tumor interface response (IR) postchemotherapy and post-CRT into type I (remained/became more defined) and type II (became less defined). Overall survival (OS) and progression-free survival (PFS) from time of CRT were estimated using Kaplan-Meier method. P ≤ .05 was considered significant.

RESULTS

Twenty-three patients started and finished on protocol (LAPC = 14, BRPC = 9). No grade 3 and 4 toxicities were reported in level 1 (n = 3) or level 2 (n = 3) initial groups. Two patients in the initial level 3 group developed dose limiting toxicity, establishing level 2 dose as the maximal tolerated dose. Level 2 group was expanded for additional 15 patients (for a total of 23 on trial), 5 of whom developed grade 3 toxicities. Seven patients underwent surgical resection. Median OS and PFS were 21.2 and 8.1 months, respectively. Type I IR was associated with better OS (P = .004) and PFS (P = .03) compared with type II IR.

CONCLUSIONS

We established the maximum tolerated dose for nab-paclitaxel in a consolidative CRT regimen for pancreatic ductal adenocarcinoma. Preliminary efficacy results warrant phase 2 trial evaluation. IR may be used for personalized treatment.

Gallbladder cancer

Gallbladder cancer (GBC) is the most common cancer of the biliary tract, characterized by a very poor prognosis when diagnosed at advanced stages owing to its aggressive behaviour and limited therapeutic options. Early detection at a curable stage remains challenging because patients rarely exhibit symptoms; indeed, most GBCs are discovered incidentally following cholecystectomy for symptomatic gallbladder stones. Long-standing chronic inflammation is an important driver of GBC, regardless of the lithiasic or non-lithiasic origin. Advances in omics technologies have provided a deeper understanding of GBC pathogenesis, uncovering mechanisms associated with inflammation-driven tumour initiation and progression. Surgical resection is the only treatment with curative intent for GBC but very few cases are suitable for resection and most adjuvant therapy has a very low response rate. Several unmet clinical needs require to be addressed to improve GBC management, including discovery and validation of reliable biomarkers for screening, therapy selection and prognosis. Standardization of preneoplastic and neoplastic lesion nomenclature, as well as surgical specimen processing and sampling, now provides reproducible and comparable research data that provide a basis for identifying and implementing early detection strategies and improving drug discovery. Advances in the understanding of next-generation sequencing, multidisciplinary care for GBC, neoadjuvant and adjuvant strategies, and novel systemic therapies including chemotherapy and immunotherapies are gradually changing the treatment paradigm and prognosis of this recalcitrant cancer.

The Clinical Landscape of Cell-Free DNA Alterations in 1,671 Patients with Advanced Biliary Tract Cancer

BACKGROUND

Targeted therapies have transformed clinical management of advanced biliary tract cancer (BTC). Cell-free DNA (cfDNA) analysis is an attractive approach for cancer genomic profiling that overcomes many limitations of traditional tissue-based analysis. We examined cfDNA as a tool to inform clinical management of patients with advanced BTC and generate novel insights into BTC tumor biology.

PATIENTS AND METHODS

We analyzed next-generation sequencing data of 2,068 cfDNA samples from 1,671 patients with advanced BTC generated with Guardant360. We performed clinical annotation on a multi-institutional subset (n=225) to assess intra-patient cfDNA-tumor concordance and the association of cfDNA variant allele fraction (VAF) with clinical outcomes.

RESULTS

Genetic alterations were detected in cfDNA in 84% of patients, with targetable alterations detected in 44% of patients. FGFR2 fusions, IDH1 mutations, and BRAF V600E were clonal in majority of cases, affirming these targetable alterations as early driver events in BTC. Concordance between cfDNA and tissue for mutation detection was high for IDH1 mutations (87%) and BRAF V600E (100%), and low for FGFR2 fusions (18%). cfDNA analysis uncovered novel putative mechanisms of resistance to targeted therapies, including mutation of the cysteine residue (FGFR2 C492F) to which covalent FGFR inhibitors bind. High pre-treatment cfDNA VAF associated with poor prognosis and shorter response to chemotherapy and targeted therapy. Finally, we report the frequency of promising targets in advanced BTC currently under investigation in other advanced solid tumors, including KRAS G12C (1.0%), KRAS G12D (5.1%), PIK3CA mutations (6.8%), and ERBB2 amplifications (4.9%).

CONCLUSIONS

These findings from the largest and most comprehensive study to date of cfDNA from patients with advanced BTC highlight the utility of cfDNA analysis in current management of this disease. Characterization of oncogenic drivers and mechanisms of therapeutic resistance in this study will inform drug development efforts to reduce mortality for patients with BTC.

Temporal Changes in Cholangiocarcinoma Incidence and Mortality in the United States from 2001 to 2017

Background

Previous studies report increasing cholangiocarcinoma (CCA) incidence up to 2015. This contemporary retrospective analysis of CCA incidence and mortality in the US from 2001-2017 assessed whether CCA incidence continued to increase beyond 2015.

Patients and Methods

Patients (≥18 years) with CCA were identified in the National Cancer Institute Surveillance, Epidemiology, and End Results 18 cancer registry (International Classification of Disease for Oncology [ICD-O]-3 codes: intrahepatic [iCCA], C221; extrahepatic [eCCA], C240, C241, C249). Cancer of unknown primary (CUP) cases were identified (ICD-O-3: C809; 8140/2, 8140/3, 8141/3, 8143/3, 8147/3) because of potential misclassification as iCCA.

Results

Forty-thousand-and-thirty CCA cases (iCCA, n=13,174; eCCA, n=26,821; iCCA and eCCA, n=35) and 32,980 CUP cases were analyzed. From 2001-2017, CCA, iCCA, and eCCA incidence (per 100 000 person-years) increased 43.8% (3.08 to 4.43), 148.8% (0.80 to 1.99), and 7.5% (2.28 to 2.45), respectively. In contrast, CUP incidence decreased 54.4% (4.65 to 2.12). CCA incidence increased with age, with greatest increase among younger patients (18-44 years, 81.0%). Median overall survival from diagnosis was 8, 6, 9, and 2 months for CCA, iCCA, eCCA, and CUP. From 2001-2016, annual mortality rate declined for iCCA (57.1% to 41.2%) and generally remained stable for eCCA (40.9% to 37.0%) and for CUP (64.3% to 68.6%).

Conclusions

CCA incidence continued to increase from 2001-2017, with greater increase in iCCA versus eCCA, whereas CUP incidence decreased. The divergent CUP versus iCCA incidence trends, with overall greater absolute change in iCCA incidence, provide evidence for a true increase in iCCA incidence that may not be wholly attributable to CUP reclassification.

Radiographic and Serologic Response to First-Line Chemotherapy in Unresected Localized Pancreatic Cancer

BACKGROUND

This study aimed to determine the clinical relevance of putative radiographic and serologic metrics of chemotherapy response in patients with localized pancreatic cancer (LPC) who do not undergo pancreatectomy. Studies evaluating the response of LPC to systemic chemotherapy have focused on histopathologic analyses of resected specimens, but such specimens are not available for patients who do not undergo resection. We previously showed that changes in tumor volume and CA 19-9 levels provide a clinical readout of histopathologic response to preoperative therapy.

METHODS

Our institutional database was searched for patients with LPC who were treated with first-line chemotherapy between January 2010 and December 2017 and did not undergo pancreatectomy. Radiographic response was measured using RECIST 1.1 and tumor volume. The volume of the primary tumor was compared between pretreatment and posttreatment images. The percentage change in tumor volume (%Δvol) was calculated as a percentage of the pretreatment volume. Serologic response was measured by comparing pretreatment and posttreatment CA 19-9 levels. We established 3 response groups by combining these metrics: (1) best responders with a decline in %Δvol in the top quartile and in CA 19-9, (2) nonresponders with an increase in %Δvol and in CA 19-9, and (3) other patients.

RESULTS

This study included 329 patients. Individually, %Δvol and change in CA 19-9 were associated with overall survival (OS) (P≤.1), but RECIST 1.1 was not. In all, 73 patients (22%) were best responders, 42 (13%) were nonresponders, and there were 214 (65%) others. Best responders lived significantly longer than nonresponders and others (median OS, 24 vs 12 vs 17 months, respectively; P<.01). A multivariable model adjusting for type of chemotherapy regimen, number of chemotherapy doses, and receipt of radiotherapy showed that best responders had longer OS than did the other cohorts (hazard ratio [HR], 0.35; 95% CI, 0.21-0.58 for best responders, and HR, 0.55; 95% CI, 0.37-0.83 for others).

CONCLUSIONS

Changes in tumor volume and serum levels of CA 19-9-but not RECIST 1.1-represent reliable metrics of response to systemic chemotherapy. They can be used to counsel patients and families on survival expectations even if pancreatectomy is not performed.

Single cell sequencing reveals trajectory of tumor-infiltrating lymphocyte states in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has few effective treatments. Immunotherapy, an attractive alternative strategy, remains challenging with the lack of knowledge on the tumor-infiltrating lymphocyte (TIL) landscape in PDAC. To generate a reference of T-cell subpopulations, we profiled 80,000 T cells from 57 PDAC, 22 uninvolved/normal samples, and cultured TIL using single-cell transcriptomic and T-cell receptor analysis. These data revealed 20 cell states and heterogeneous distributions of TIL populations. The CD8+ TIL contained a putative transitional GZMK+ population based on TCR clonotype sharing, and cell-state trajectory analysis showed similarity to a GZMB+PRF1+ cytotoxic and a CXCL13+ dysfunctional population. Statistical analysis suggested that certain TIL states, such as dysfunctional and inhibitory populations, often occurred together. Finally, analysis of cultured TIL revealed that high-frequency clones from effector populations were preferentially expanded. These data provide a framework for understanding the PDAC TIL landscape for future TIL use in immunotherapy for PDAC.

Ablative liver radiotherapy for unresected intrahepatic cholangiocarcinoma: Patterns of care and survival in the United States

BACKGROUND

Single-institution studies have shown the oncologic benefit of ablative liver radiotherapy (A-RT) for patients with unresectable intrahepatic cholangiocarcinoma (ICC). However, adoption of A-RT across the United States and its associated outcomes are unknown.

METHODS

We queried the National Cancer Data Base for nonsurgically managed patients with ICC diagnosed between 2004 and 2018. Patients were labeled A-RT for receipt of biologically effective doses (BED10 ) ≥ 80.5 Gy and conventional RT (Conv-RT) for lower doses. Associations with A-RT use and overall survival were identified using logistic and Cox regressions, respectively.

RESULTS

Of 27,571 patients, the most common treatments were chemotherapy without liver RT (45%), no chemotherapy or liver RT (42%), and liver RT ± chemotherapy (13%). Use of liver RT remained constant over time. Of 1112 patients receiving liver RT with known doses, RT was 73% Conv-RT (median BED10 , 53 Gy; median, 20 fractions) and 27% A-RT (median BED10 , 100 Gy; median, 5 fractions). Use of A-RT increased from 5% in 2004 to 48% in 2018 (Ptrend < .001). With a median follow-up of 52.3 months, median survival estimates for Conv-RT and A-RT were 12.8 and 23.7 months (P < .001), respectively. On multivariable analysis, stage III and IV disease correlated with a higher risk of death, whereas chemotherapy and A-RT correlated with a lower risk.

CONCLUSIONS

Although A-RT has been increasingly used, use of liver RT as a whole in the United States remained constant despite growing evidence supporting its use, suggesting continued unmet need. A-RT is associated with longer survival versus Conv-RT.

LAY SUMMARY

Bile duct cancer is a rare, deadly disease that often presents at advanced stages. Single-institution retrospective studies have demonstrated that use of high-dose radiotherapy may be associated with longer survival, but larger studies have not been conducted. We used a large, national cancer registry of patients diagnosed between 2004 and 2018 to show that liver radiotherapy use remains low in the United States, despite growing evidence that patients who receive it live longer. Furthermore, we showed that patients who received high-dose radiotherapy lived longer than those who received lower doses. Greater awareness of the benefits of liver radiotherapy is needed to improve patient outcomes.

Abstract 2618: Convergent MAPK pathway alterations mediate acquired resistance to FGFR inhibitors in cholangiocarcinoma with FGFR fusions/rearrangements

Purpose: Genomic aberrations in fibroblast growth factor receptor (FGFR) are oncogenic drivers in several cancers. FGFR inhibitors (FGFRi) have demonstrated antitumor activity in cholangiocarcinoma (CCA) with FGFR2 fusions/rearrangements, though acquired resistance remains a therapeutic challenge and has been linked to FGFR2 mutations other than fusions/rearrangements. We sought to investigate mechanisms of acquired resistance to FGFRi and approaches to overcome resistance.

Methods: Longitudinal plasma samples were collected from patients with FGFR pathway alterations enrolled in the futibatinib phase I trial (NCT02052778) and sequenced using a targeted, 73-gene panel. A separate retrospective analysis was conducted to evaluate possible evolution of genomic aberrations in CCA patients with FGFR2 fusion/rearrangement who had additional tumor and/or plasma next-generation sequencing (NGS) following FGFRi therapy. To assess the efficacy of futibatinib in cells with FGFR2 fusions in vitro, a FGFR2-BICC1 fusion H69 cholangiocyte cell line was developed. MAPK pathway alterations (BRAF_V600E or KRAS_G12D) were introduced to determine the impact of these co-alterations on FGFRi sensitivity, and combinations were tested to determine if efficacy could be enhanced. Cell viability assays, colony formation assays, and western blots were utilized to determine the effects of these agents in engineered cells.

Results: A total of 58 plasma samples were collected from 17 patients with FGFR pathway alterations who were enrolled in the futibatinib phase I trial, including 13 (76.5%) of which had CCA. One patient with a FGFR2-CTNNA3 fusion who had NRAS G12D and BRAF A694T at baseline which were undetected during treatment had a dramatic increase in their variant allele frequency (VAF) upon progression (4.2%-0.0%-100% and 2.8%-0.0%-50.9%, respectively). Further, additional MAPK alterations were detected at time of progression, including BRAF V600E, NRAS Q61K, NRAS G12C, NRAS G13D and KRAS G12K mutations. In our separate retrospective series, of 17 patients who underwent repeat tumor and/or plasma NGS following treatment with one or more FGFRi, 10 (58.8%) had newly detectable alterations in MAPK pathway genes, 10 (58.8%) had new FGFR2 alterations, and 7 (41.2%) developed new alterations in both FGFR2 and MAPK pathway genes. In vitro studies demonstrated that in isogenic H69 biliary cell lines, introduction of FGFR2-BICC1 robustly sensitized to FGFRi when compared to a parental cell line, which was blunted by the introduction of secondary KRAS_G12D or BRAF_V600E mutations.

Conclusions: Convergent genomic evolution in the MAPK pathway may be a potential mechanism of acquired resistance to FGFRi therapy. Work is ongoing to determine if targeting co-alterations may enhance the efficacy of FGFRi in FGFR2-fusion driven malignancies.

Citation Format: TImothy P. DiPeri, Ming Zhao, Tyler Moss, Michael Kahle, Payal Rauli, Sunyoung S. Lee, Abdel Halim, Hiroshi Hirai, Volker Wacheck, Karim Benhadji, Jordi Rodon, Milind Javle, Funda Meric-Bernstam. Convergent MAPK pathway alterations mediate acquired resistance to FGFR inhibitors in cholangiocarcinoma with FGFR fusions/rearrangements [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2618.

Abstract 2847: Simultaneous TCR and transcriptomic sequencing of single Tcells defines biological subtypes in pancreatic cancer for adoptive Tcell therapy

Pancreatic ductal adenocarcinoma (PDAC) is a highly fatal tumor-type with very few effective treatment strategies. Attempts to improve outcomes using immune checkpoint blockade therapy have also failed, likely because the overall Tcell infiltration in this tumor-type is low. Despite this, the presence of CD3+CD8+ tumor-infiltrating lymphocytes (TIL) in PDAC is associated with improved survival outcomes, suggesting that other immune-based strategies could be more successful. Here, we examine ex vivo tumor-infiltrating Tcell expansion for adoptive Tcell therapy (ACT) as a potential strategy for treating PDAC. The focus of this study is to understand the transcriptional states of Tcells in the pancreas and PDACs and how they change with ex vivo expansion and re-infusion into patients as treatment strategy. We have performed both single cell transcriptome and TCR sequencing (scRNA-TCRseq) on 54,579 Tcells from 8 human PDAC samples and the ex vivo grown TIL from a subset of 6 patients and found 13 purported substates. Through TCR tracking of the Tcell clonotypes, we find that the expansion protocol is able to expand Tcells found in many different Tcell states in the primary tumor. Furthermore, we compared our thirteen tumor-infiltrating substates with 41,935 Tcells from two other independent single cell studies across 71 samples, and confirmed our substates to be present across all datasets.

Citation Format: Aislyn Schalck, Donastas Sakellariou-Thompson, Marie-Andrée Forget, Emi Sei, Tara Hughes, Shanshan Bai, Min Hu, Tapsi Kumar, Mark Hurd, Matthew Katz, Chine-Wei Tzeng, Shubham Pant, Milind Javle, Anirban Maitra, Cara Haymaker, Michael Kim, Nicholas Navin, Chantale Bernatchez. Simultaneous TCR and transcriptomic sequencing of single Tcells defines biological subtypes in pancreatic cancer for adoptive Tcell therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2847.

Abstract 5237: B-Raf V600E harboring non-melanoma cancers treated with Vemurafenib monotherapy and in combination with Everolimus/Sorafenib/Crizotinib/Paclitaxel+ Carboplatin: A pooled analysis of five phase 1/2 studies

BACKGROUND: BRAF V600 mutations are driver oncogenes in multiple human cancers. Given complex resistance mechanisms beyond combined MEK inhibition, limited data exists to evaluate combinations with CRAF/ARAF/MET/mTOR inhibitors and cytotoxic chemotherapy in sustaining response and overcoming resistance. We explore patient outcomes comparing vemurafenib monotherapy with the above combination therapies in this analysis.

METHODS: A pooled analysis of 5 phase 1/2 clinical trials containing vemurafenib was conducted between January 2012 and October 2020 in BRAF V600E mutant advanced or metastatic tumors. Overall survival (OS) and Progression free survival (PFS) in vemurafenib monotherapy (V) arm compared with vemurafenib + crizotinib (VC), vemurafenib + sorafenib (VS), vemurafenib + everolimus (VE) and vemurafenib + paclitaxel + carboplatin (VPC) arms were assessed. Objective Response Rate (ORR) and Clinical Benefit Rate (CBR=CR+PR+SD≥6 months) and safety profile of combination arms were also explored.

RESULTS: 99 patients were enrolled across 5 studies. Median age was 57 years with 78% of ECOG 1 and M:F ratio at 1:1. Tumor types included NSCLC (13%), Thyroid cancer (12%), Low and High-grade Gliomas (7%), Colorectal cancer (6%), Cholangiocarcinoma (5%) and ECD (3%). V arm derived greatest clinical benefit with median OS at 21 months while addition of PC arm dropped median OS to 2 months. Inferior OS was seen in VPC arm when compared to V arm (p=0.00616). Median PFS peaked at 11 months in VC arm versus 3 months for the VPC arm. Of 85 evaluable patients, 2 complete responses were noted in the V (n=25) and VPC (n=14) arms and 8 Partial Responses (PR) were noted with 5 (18%) patients with NSCLC in V arm followed by 4 PRs in the VC (n=12) arm. PR rates were equally seen in the other arms. ORR (36%) and CBR (40%) rates were the highest for the V arm. G3/G4 treatment related adverse events with neutropenia (63%), thrombocytopenia (50%) and fatigue (63%) were highest in VPC. 1 patient died from G4 thrombocytopenia with intracranial hemorrhage in the VPC arm.

CONCLUSIONS: No significant added clinical benefit was noted when vemurafenib was combined with other targeted agents or cytotoxic therapy. Combinations resulted in poor tolerance and need for dose reductions compromising clinical efficacy. Prospective studies to analyze resistance mechanisms to BRAF inhibitor therapy in BRAF+ tumors and in real time tailoring therapy based on co-occuring alterations is warranted.

Citation Format: Blessie Elizabeth Nelson, Jason Roszik, Filip Janku, David Hong, Shumei Kato, Aung Naing, Sarina Piha-Paul, Siqing Fu, Apostolia Tsimberidou, Maria Cabanillas, Naifa Busaidy, Milind Javle, Lauren Byers, John Heymach, Funda Meric-Bernstam, Vivek Subbiah. B-Raf V600E harboring non-melanoma cancers treated with Vemurafenib monotherapy and in combination with Everolimus/Sorafenib/Crizotinib/Paclitaxel+ Carboplatin: A pooled analysis of five phase 1/2 studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5237.

Phase II Study of Ramucirumab in Advanced Biliary Tract Cancer Previously Treated By Gemcitabine-Based Chemotherapy

PURPOSE

VEGF receptor-2 (VEGFR-2)-mediated angiogenesis contributes to pathogenesis of biliary tract cancers (BTC). We investigated ramucirumab, a mAb targeting VEGFR-2 for treatment of advanced, chemorefractory BTC.

PATIENTS AND METHODS

This is a phase II, single-arm trial for advanced, unresectable, pre-treated patients with BTC with ECOG 0/1, adequate liver, renal, and marrow functions. Ramucirumab was administered at 8 mg/kg, 2 weekly with restaging performed 8 weekly. Primary endpoint was progression-free survival (PFS). Secondary endpoints were overall response rate (ORR), disease control rate (DCR), overall survival (OS), and toxicity. Exploratory endpoints included correlation of tumor mutational status with PFS and OS.

RESULTS

61 patients were enrolled: the median age was 58.5 years; 59 with stage IV disease; 62%, intrahepatic cholangiocarcinoma; 22%, gallbladder cancer; and 16%, extrahepatic cholangiocarcinoma. All received prior chemotherapy: 52% had 1 prior, and rest ≥2 prior lines. Median treatment duration was 10.1 weeks (range, 2.1-86). Median PFS was 3.2 months [95% confidence interval (CI), 2.1-4.8]; median OS, 9.5 months (95% CI, 5.8-13.6). One (1.7%) patient achieved partial response; 26 (43.3%), stable disease; and 25 (41.7%), disease progression; DCR, 45%. Median 6-month PFS and OS rates were 32% (95% CI, 0.22-0.46) and 58% (95% CI, 0.47-0.72). The majority of toxicities were grade 1 or 2; grade 3 proteinuria (1, 2%), hypertension (13, 22%), and pulmonary embolism (1, 2%), and grade 4 gastrointestinal bleeding (1, 2%) occurred.

CONCLUSIONS

Ramucirumab was well tolerated and resulted in PFS similar to that achieved with other chemotherapy regimens used historically for chemorefractory BTC.

Arterial enhancement pattern predicts survival in patients with resectable and unresectable intrahepatic cholangiocarcinoma

BACKGROUND

In patients undergoing resection of intrahepatic cholangiocarcinoma (ICC), hypervascularity during the arterial phase of contrast-enhanced computed tomography (CT) is associated with better prognosis than hypovascularity. However, the prognostic implications of arterial enhancement pattern in patients with unresectable ICC are unknown. We assessed the prognostic implications of arterial enhancement pattern in patients with resectable and unresectable ICC.

METHODS

Consecutive patients who underwent surgery or gemcitabine-plus-cisplatin chemotherapy for ICC during 2003-2015 and CT with dynamic enhancement for diagnosis were included. After review by 2 radiologists, tumors were categorized according to the percentage of the tumor exhibiting arterial enhancement as hypervascular (>50% of tumor exhibiting enhancement), peripherally enhancing (10%-50%), and hypovascular (<10%). In each cohort (surgical and medical), overall survival (OS) curves were generated using the Kaplan-Meier method, and differences between curves were evaluated with Cox analysis.

RESULTS

The study included 56 patients treated surgically and 89 patients with unresectable ICC. Mean (standard deviation) tumor density in the hypervascular, peripherally enhancing, and hypovascular groups was 119.3 (45.2) Hounsfield units (HU), 72.1 (15.9) HU, and 59.9 (14.4) HU, respectively, in the surgical cohort and 93.6 (17.5) HU, 66.6 (16.2) HU, and 48.7 (14.3) HU, respectively, in the medical cohort. In both cohorts, the 5-year OS rate was significantly higher in the hypervascular group than in the hypovascular group (surgical, 67.6% vs 22.5%, P = .038; medical, 15.4% vs 0%, P = .030). In both cohorts, a Cox proportional hazards model analysis showed that hypervascularity was significantly associated with better OS.

CONCLUSION

Hypervascularity during the arterial CT phase is a prognostic biomarker in patients undergoing ICC resection and patients with unresectable ICC.

Survival following liver transplantation for locally advanced, unresectable intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) has previously been considered a contraindication to liver transplantation (LT). However, recent series showed favorable outcomes for LT after neoadjuvant therapy. Our center developed a protocol for neoadjuvant therapy and LT for patients with locally advanced, unresectable iCCA in 2010. Patients undergoing LT were required to demonstrate disease stability for 6 months on neoadjuvant therapy with no extrahepatic disease. During the study period, 32 patients were listed for LT and 18 patients underwent LT. For transplanted patients, the median number of iCCA tumors was 2, and the median cumulative tumor diameter was 10.4 cm. Patients receiving LT had an overall survival at 1-, 3-, and 5-years of 100%, 71%, and 57%. Recurrences occurred in seven patients and were treated with systemic therapy and resection. The study population had a higher than expected proportion of patients with genetic alterations in fibroblast growth factor receptor (FGFR) and DNA damage repair pathways. These data support LT as a treatment for highly selected patients with locally advanced, unresectable iCCA. Further studies to identify criteria for LT in iCCA and factors predicting survival are warranted.

Monitoring of Dynamic Changes and Clonal Evolution in Circulating Tumor DNA From Patients With IDH-Mutated Cholangiocarcinoma Treated With Isocitrate Dehydrogenase Inhibitors

PURPOSE

IDH mutations occur in about 30% of patients with cholangiocarcinoma. Analysis of mutations in circulating tumor DNA (ctDNA) can be performed by droplet digital polymerase chain reaction (ddPCR). The analysis of ctDNA is a feasible approach to detect IDH mutations.

METHODS

We isolated ctDNA from the blood of patients with IDH-mutated advanced cholangiocarcinoma collected at baseline, on therapy, and at progression to isocitrate dehydrogenase (IDH) inhibitors.

RESULTS

Of 31 patients with IDH1R132 (n = 26) or IDH2R172 mutations (n = 5) in the tumor, IDH mutations were detected in 84% of ctDNA samples analyzed by ddPCR and in 83% of ctDNA samples analyzed by next-generation sequencing (NGS). Patients with a low variant allele frequency of ctDNA detected by NGS at baseline had a longer median time to treatment failure compared to patients with high variant allele frequency of ctDNA (3.6 v 1.5 months; P = .008). Patients with a decrease in IDH-mutated ctDNA on therapy by ddPCR compared with no change/increase had a trend to a longer median survival (P = .07). Most frequent emergent alterations in ctDNA by NGS at progression were ARID1A (n = 3) and TP53 mutations (n = 3).

CONCLUSION

Detection of IDH mutations in ctDNA in patients with advanced cholangiocarcinoma is feasible, and dynamic changes in ctDNA can correspond with the clinical course and clonal evolution.

Gallbladder reporting and data system (GB-RADS) for risk stratification of gallbladder wall thickening on ultrasonography: an international expert consensus

The Gallbladder Reporting and Data System (GB-RADS) ultrasound (US) risk stratification is proposed to improve consistency in US interpretations, reporting, and assessment of risk of malignancy in gallbladder wall thickening in non-acute setting. It was developed based on a systematic review of the literature and the consensus of an international multidisciplinary committee comprising expert radiologists, gastroenterologists, gastrointestinal surgeons, surgical oncologists, medical oncologists, and pathologists using modified Delphi method. For risk stratification, the GB-RADS system recommends six categories (GB-RADS 0-5) of gallbladder wall thickening with gradually increasing risk of malignancy. GB-RADS is based on gallbladder wall features on US including symmetry and extent (focal vs. circumferential) of involvement, layered appearance, intramural features (including intramural cysts and echogenic foci), and interface with the liver. GB-RADS represents the first collaborative effort at risk stratifying the gallbladder wall thickening. This concept is in line with the other US-based risk stratification systems which have been shown to increase the accuracy of detection of malignant lesions and improve management.

Corticosteroid-Refractory Myositis After Dual BRAF and MEK Inhibition in a Patient with BRAF V600E-Mutant Metastatic Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma is a rare malignancy, which is rich in actionable alterations. Genomic aberrations in the mitogen-activated protein kinase (MAPK) pathway are common, and BRAF exon 15 p.V600E mutations are present in 5–7% of biliary tract cancers (BTC). Dual inhibition of BRAF and MEK has been established for BRAF-mutated melanoma and lung cancer, and recent basket trials have shown efficacy of this combination in BRAF V600E-mutant BTCs. Here, we report on a patient with BRAF exon 15 p.V600E mutant metastatic intrahepatic cholangiocarcinoma who was started on BRAF and MEK inhibition with vemurafenib and combimetinib. Shortly thereafter, he developed debilitating myositis, which was refractory to corticosteroids, requiring therapeutic plasma exchange and intravenous immunoglobulin. We also review BRAF as a target in BTCs, relevant clinical trials, and adverse events associated with BRAF and MEK inhibition.

Futibatinib, an Irreversible FGFR1-4 Inhibitor, in Patients with Advanced Solid Tumors Harboring FGF/FGFR Aberrations: A Phase I Dose-Expansion Study

Futibatinib, a highly selective, irreversible FGFR1-4 inhibitor, was evaluated in a large multihistology phase I dose-expansion trial that enrolled 197 patients with advanced solid tumors. Futibatinib demonstrated an objective response rate (ORR) of 13.7%, with responses in a broad spectrum of tumors (cholangiocarcinoma and gastric, urothelial, central nervous system, head and neck, and breast cancer) bearing both known and previously uncharacterized FGFR1-3 aberrations. The greatest activity was observed in FGFR2 fusion/rearrangement-positive intrahepatic cholangiocarcinoma (ORR, 25.4%). Some patients with acquired resistance to a prior FGFR inhibitor also experienced responses with futibatinib. Futibatinib demonstrated a manageable safety profile. The most common treatment-emergent adverse events were hyperphosphatemia (81.2%), diarrhea (33.5%), and nausea (30.4%). These results formed the basis for ongoing futibatinib phase II/III trials and demonstrate the potential of genomically selected early-phase trials to help identify molecular subsets likely to benefit from targeted therapy. SIGNIFICANCE: This phase I dose-expansion trial demonstrated clinical activity and tolerability of the irreversible FGFR1-4 inhibitor futibatinib across a broad spectrum of FGFR-aberrant tumors. These results formed the rationale for ongoing phase II/III futibatinib trials in cholangiocarcinoma, breast cancer, gastroesophageal cancer, and a genomically selected disease-agnostic population.This article is highlighted in the In This Issue feature, p. 275.

The immunogenomic landscape of resected intrahepatic cholangiocarcinoma

BACKGROUND AND AIMS

Cholangiocarcinoma (CCA) is a deadly and highly therapy-refractory cancer of the bile ducts, with early results from immune checkpoint blockade trials showing limited responses. Whereas recent molecular assessments have made bulk characterizations of immune profiles and their genomic correlates, spatial assessments may reveal actionable insights.

APPROACH AND RESULTS

Here, we have integrated immune checkpoint-directed immunohistochemistry with next-generation sequencing of resected intrahepatic CCA samples from 96 patients. We found that both T-cell and immune checkpoint markers are enriched at the tumor margins compared to the tumor center. Using two approaches, we identify high programmed cell death protein 1 or lymphocyte-activation gene 3 and low CD3/CD4/inducible T-cell costimulator specifically in the tumor center as associated with poor survival. Moreover, loss-of-function BRCA1-associated protein-1 mutations are associated with and cause elevated expression of the immunosuppressive checkpoint marker, B7 homolog 4.

CONCLUSIONS

This study provides a foundation on which to rationally improve and tailor immunotherapy approaches for this difficult-to-treat disease.

Benchmarking Outcomes after Ablative Radiotherapy for Molecularly Characterized Intrahepatic Cholangiocarcinoma

We have previously shown that ablative radiotherapy (A-RT) with a biologically effective dose (BED10) ≥ 80.5 Gy for patients with unresectable intrahepatic cholangiocarcinoma (ICC) is associated with longer survival. Despite recent large-scale sequencing efforts in ICC, outcomes following RT based on genetic alterations have not been described. We reviewed records of 156 consecutive patients treated with A-RT for unresectable ICC from 2008 to 2020. For 114 patients (73%), next-generation sequencing provided molecular profiles. The overall survival (OS), local control (LC), and distant metastasis-free survival (DMFS) were estimated using the Kaplan-Meier method. Univariate and multivariable Cox analyses were used to determine the associations with the outcomes. The median tumor size was 7.3 (range: 2.2-18.2) cm. The portal vein thrombus (PVT) was present in 10%. The RT median BED10 was 98 Gy (range: 81-144 Gy). The median (95% confidence interval) follow-up was 58 (42-104) months from diagnosis and 39 (33-74) months from RT. The median OS was 32 (29-35) months after diagnosis and 20 (16-24) months after RT. The one-year OS, LC, and intrahepatic DMFS were 73% (65-80%), 81% (73-87%), and 34% (26-42%). The most common mutations were in IDH1 (25%), TP53 (22%), ARID1A (19%), and FGFR2 (13%). Upon multivariable analysis, the factors associated with death included worse performance status, larger tumor, metastatic disease, higher CA 19-9, PVT, satellitosis, and IDH1 and PIK3CA mutations. TP53 mutation was associated with local failure. Further investigation into the prognostic value of individual mutations and combinations thereof is warranted.

Infigratinib (BGJ398) in previously treated patients with advanced or metastatic cholangiocarcinoma with FGFR2 fusions or rearrangements: mature results from a multicentre, open-label, single-arm, phase 2 study

BACKGROUND

Treatment options are sparse for patients with advanced cholangiocarcinoma after progression on first-line gemcitabine-based therapy. FGFR2 fusions or rearrangements occur in 10-16% of patients with intrahepatic cholangiocarcinoma. Infigratinib is a selective, ATP-competitive inhibitor of fibroblast growth factor receptors. We aimed to evaluate the antitumour activity of infigratinib in patients with locally advanced or metastatic cholangiocarcinoma, FGFR2 alterations, and previous gemcitabine-based treatment.

METHODS

This multicentre, open-label, single-arm, phase 2 study recruited patients from 18 academic centres and hospitals in the USA, Belgium, Spain, Germany, Singapore, Taiwan, and Thailand. Eligible participants were aged 18 years or older, had histologically or cytologically confirmed, locally advanced or metastatic cholangiocarcinoma and FGFR2 fusions or rearrangements, and were previously treated with at least one gemcitabine-containing regimen. Patients received 125 mg of oral infigratinib once daily for 21 days of 28-day cycles until disease progression, intolerance, withdrawal of consent, or death. Radiological tumour evaluation was done at baseline and every 8 weeks until disease progression via CT or MRI of the chest, abdomen, and pelvis. The primary endpoint was objective response rate, defined as the proportion of patients with a best overall response of a confirmed complete or partial response, as assessed by blinded independent central review (BICR) according to Response Evaluation Criteria in Solid Tumors, version 1.1. The primary outcome and safety were analysed in the full analysis set, which comprised all patients who received at least one dose of infigratinib. This trial is registered with ClinicalTrials.gov, NCT02150967, and is ongoing.

FINDINGS

Between June 23, 2014, and March 31, 2020, 122 patients were enrolled into our study, of whom 108 with FGFR2 fusions or rearrangements received at least one dose of infigratinib and comprised the full analysis set. After a median follow-up of 10·6 months (IQR 6·2-15·6), the BICR-assessed objective response rate was 23·1% (95% CI 15·6-32·2; 25 of 108 patients), with one confirmed complete response in a patient who only had non-target lesions identified at baseline and 24 partial responses. The most common treatment-emergent adverse events of any grade were hyperphosphataemia (n=83), stomatitis (n=59), fatigue (n=43), and alopecia (n=41). The most common ocular toxicity was dry eyes (n=37). Central serous retinopathy-like and retinal pigment epithelial detachment-like events occurred in 18 (17%) patients, of which ten (9%) were grade 1, seven (6%) were grade 2, and one (1%) was grade 3. There were no treatment-related deaths.

INTERPRETATION

Infigratinib has promising clinical activity and a manageable adverse event profile in previously treated patients with locally advanced or metastatic cholangiocarcinoma harbouring FGFR2 gene fusions or rearrangements, and so represents a potential new therapeutic option in this setting.

FUNDING

QED Therapeutics and Novartis.

Fixed-Dose Netupitant and Palonosetron for Chronic Nausea in Cancer Patients: A Double-Blind, Placebo Run-in Pilot Randomized Clinical Trial

CONTEXT

No clinical trials have examined the effect of netupitant/palonosetron (NEPA) on chronic nausea in patients with cancer.

OBJECTIVES

In this pilot randomized trial, we assessed the efficacy of NEPA and placebo on chronic nausea.

METHODS

This double-blind, parallel, randomized trial enrolled patients with cancer and chronic nausea for at least 1 month, intensity ≥4/10 and not on moderately or highly emetogenic systemic therapies. Patients started with a placebo run-in period from days 1 to 5; those without a placebo response proceeded to the double-blinded phase between days 6 to 15 (NEPA: placebo 2:1 ratio). The primary outcome was within-group change in average nausea over the 24 hours on a 0-10 numeric rating scale between day 5 and 15.

RESULTS

Among the 53 enrolled patients, 46 proceeded to placebo run-in and 33 had blinded treatment (22 NEPA and 11 placebo). We observed a statistically significant within-group improvement in nausea numeric rating scale between day 5 and 15 in the NEPA group (mean change, -2.0; 95% CI, -3.1 to -0.8) and the placebo group (mean change, -2.3; 95% CI, -3.9 to -0.7). A complete response was achieved in 8 (38%) patients in the NEPA group and 2 (20%) in the placebo group by day 15. No grade 3-4 toxicities were attributed to NEPA. There were no statistically significant between-group differences for the primary/secondary outcomes.

CONCLUSIONS

NEPA and placebo were associated with similar magnitude of within-group improvement in chronic nausea without significant between-group differences (Clinicaltrials.gov NCT03040726).

Pertuzumab and trastuzumab for HER2-positive, metastatic biliary tract cancer (MyPathway): a multicentre, open-label, phase 2a, multiple basket study

BACKGROUND

Systemic therapies for metastatic biliary tract cancers are few, and patients have a median overall survival of less than 1 year. MyPathway evaluates the activity of US Food and Drug Administration-approved therapies in non-indicated tumours with potentially actionable molecular alterations. In this study, we present an analysis of patients with metastatic biliary tract cancers with HER2 amplification, overexpression, or both treated with a dual anti-HER2 regimen, pertuzumab plus trastuzumab, from MyPathway.

METHODS

MyPathway is a non-randomised, multicentre, open-label, phase 2a, multiple basket study. Patients aged 18 years and older with previously treated metastatic biliary tract cancers with HER2 amplification, HER2 overexpression, or both and an Eastern Cooperative Oncology Group performance status of 0-2 were enrolled from 23 study sites in the USA and received intravenous pertuzumab (840 mg loading dose, then 420 mg every 3 weeks) plus trastuzumab (8 mg/kg loading dose, then 6 mg/kg every 3 weeks). The primary endpoint was investigator-assessed objective response rate according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. The primary outcome and adverse events were analysed in all patients who received at least one dose of pertuzumab and trastuzumab. This trial is registered with ClinicalTrials.gov, NCT02091141, and is ongoing.

FINDINGS

39 patients enrolled in the MyPathway HER2 biliary tract cancer cohort between Oct 28, 2014, and May 29, 2019, were evaluable for anti-tumour activity by the March 10, 2020, data cutoff date. Median follow-up was 8·1 months (IQR 2·7-15·7). Nine of 39 patients achieved a partial response (objective response rate 23% [95% CI 11-39]). Grade 3-4 treatment-emergent adverse events were reported in 18 (46%) of 39 patients, most commonly increased alanine aminotransferase and increased aspartate aminotransferase (each five [13%] of 39). Treatment-related grade 3 adverse events were reported in three (8%) of 39 patients, including increased alanine aminotransferase, aspartate aminotransferase, blood alkaline phosphatase, and blood bilirubin. Serious treatment-emergent adverse events were observed in ten (26%) of 39 patients, of which only abdominal pain occurred in more than one patient (two [5%] of 39). There were no treatment-related serious adverse events, treatment-related grade 4 events, or deaths.

INTERPRETATION

Treatment was well tolerated in patients with previously treated HER2-positive metastatic biliary tract cancer. The response rate is promising for the initiation of randomised, controlled trials of pertuzumab plus trastuzumab in this patient population.

FUNDING

F Hoffmann-La Roche-Genentech.

FGFR Inhibitors: Clinical Activity and Development in the Treatment of Cholangiocarcinoma

PURPOSE OF REVIEW

Cholangiocarcinoma is an aggressive cancer with a poor prognosis and limited treatment. Gene sequencing studies have identified genetic alterations in fibroblast growth factor receptor (FGFR) in a significant proportion of cholangiocarcinoma (CCA) patients. This review will discuss the FGFR signaling pathway's role in CCA and highlight the development of therapeutic strategies targeting this pathway.

RECENT FINDINGS

The development of highly potent and selective FGFR inhibitors has led to the approval of pemigatinib for FGFR2 fusion or rearranged CCA. Other selective FGFR inhibitors are currently under clinical investigation and show promising activity. Despite encouraging results, the emergence of resistance is inevitable. Studies using circulating tumor DNA and on-treatment tissue biopsies have elucidated underlying mechanisms of intrinsic and acquired resistance. There is a critical need to not only develop more effective compounds, but also innovative sequencing strategies and combinations to overcome resistance to selective FGFR inhibition. Therapeutic development of precision medicine for FGFR-altered CCA is a dynamic process of involving a comprehensive understanding of tumor biology, rational clinical trial design, and therapeutic optimization. Alterations in FGFR represent a valid therapeutic target in CCA and selective FGFR inhibitors are treatment options for this patient population.