Treatment Beyond Progression After Anti-PD-1 Blockade in Hepatocellular Carcinoma.

Immune checkpoint inhibitors (ICI) can induce atypical tumor responses including pseudoprogression in a subset of patients who may benefit from treatment beyond progression. While ICIs have emerged as frontline treatments for hepatocellular carcinoma (HCC) and are associated with clinical benefit in a minority of patients, it is unclear whether treatment beyond progression has utility in this disease type. In a multicenter cohort analysis, treatment beyond progression was associated with no new safety signals, objective responses in 5.8% of patients, and disease control in 44% of patients. Progression-free survival and overall survival were comparable between patients treated beyond progression and patients treated with subsequent therapies, demonstrating that treatment beyond progression was not detrimental to survival outcomes. Rather, treatment beyond progression may benefit select patients with HCC and could represent a viable strategy for maximizing treatment benefit in these patients. SIGNIFICANCE: Treatment beyond progression with ICIs in patients with HCC is safe and may benefit a subset of patients due to later-onset tumor responses or disease stability. These findings may guide the design of trials testing ICIs in HCC and the use of treatment beyond progression in routine practice.

Salvage Ipilimumab plus Nivolumab after Anti-PD-1/PD-L1 Therapy in Advanced Hepatocellular Carcinoma.

Combination anti-PD-(L)1/CTLA-4 blockade is approved in patients with hepatocellular carcinoma (HCC) in the first-line setting or after sorafenib, but whether this treatment has efficacy after prior anti-PD-(L)1 therapy is unknown. We performed a multicenter retrospective review of patients with advanced HCC treated with ipilimumab plus nivolumab after prior anti-PD-(L)1 therapy, excluding patients with prior anti-CTLA-4 treatment. Of the 32 patients who met our inclusion criteria, prior anti-PD-(L)1 regimens included atezolizumab plus bevacizumab (50%, n = 16), other anti-VEGF plus anti-PD-(L)1 combinations (31%, n = 10), and anti-PD-(L)1 monotherapy (19%, n = 6). The median number of prior systemic therapies was 2 (range, 1-8). The objective response rate with ipilimumab plus nivolumab by RECIST 1.1 was 22% [1 complete response (3%), 6 partial response (19%), 8 stable disease (25%), 16 progressive disease (50%), and 1 not evaluable (NE) (3%)], and objective response was associated with improved progression-free survival and overall survival. Immune-related adverse events were reported in 13 patients (41%), with no new safety signals. This study demonstrates that ipilimumab plus nivolumab has efficacy in patients with HCC who have received prior anti-PD-(L)1 therapy, suggesting that failure to respond to prior PD-(L)1 blockade should not preclude treatment with salvage ipilimumab plus nivolumab. Prospective studies are needed to define the optimal sequence of therapies. Significance: Anti-PD-(L)1 containing regimens are the preferred first-line treatment for advanced HCC, but whether salvage with PD-(L)1/CTLA-4 blockade is effective in patients who have failed prior anti-PD-(L)1 therapy is unknown. Our study demonstrates that ipilimumab plus nivolumab has clinical activity in patients with advanced HCC previously treated with anti-PD-(L)1 therapy, supporting the continued use of this regimen in the late-line setting after prior anti-PD-(L)1 exposure.

Surrogate and modified endpoints for immunotherapy in advanced hepatocellular carcinoma.

BACKGROUND AND AIMS: Immunotherapies have altered the treatment paradigm in HCC. Surrogate and modified endpoints are used to assess early success in clinical studies and guide clinical practice. We sought to determine whether surrogate endpoints and modifications to the conventional criteria for tumor response (RECIST), including modified RECIST (mRECIST) and immune-modified RECIST (imRECIST), are valid measures to predict overall survival (OS) in HCC treated with immunotherapies. APPROACH AND RESULTS: We performed an individual-level post hoc analysis of patients treated with atezolizumab and bevacizumab in the IMbrave150 trial (N = 279) and a cross-sectional analysis of a multicenter real-world patient cohort treated with immunotherapy (N = 328). Landmark analyses showed that objective response rates by RECIST were associated with greater OS including among Child-Pugh A and B patients and among patients treated with immunotherapies in the first- or second-line setting (IMbrave150: HR 0.24, 95% CI, 0.17-0.33; RW: HR 0.25, 95% CI, 0.15-0.43). Objective response rates by mRECIST or imRECIST were not associated with the greater predictive power of OS benefit (mRECIST: HR 0.30, 95% CI, 0.22-0.42; imRECIST: HR 0.36, 95% CI, 0.30-0.51). Progression-free survival determined by RECIST was only moderately correlated with OS, and this association was not improved using mRECIST or imRECIST. CONCLUSIONS: Our results clarify the utility of surrogate and modified endpoints in HCC treated with immunotherapies and support the use of RECIST objective response rates as an appropriate signal-finding measure for the evaluation of emerging treatments. Contrary to their intended purpose, mRECIST and imRECIST did not provide meaningful improvements in predicting OS benefits.

Efficacy and safety of immune checkpoint inhibitor rechallenge in individuals with hepatocellular carcinoma.

Background & Aims: We investigated the efficacy and safety of immune checkpoint inhibitor (ICI) rechallenge in patients with hepatocellular carcinoma (HCC) who received ICI-based therapies in a previous systemic line. Methods: In this international, retrospective multicenter study, patients with HCC who received at least two lines of ICI-based therapies (ICI-1, ICI-2) at 14 institutions were eligible. The main outcomes included best overall response and treatment-related adverse events. Results: Of 994 ICI-treated patients screened, a total of 58 patients (male, n = 41; 71%) with a mean age of 65.0±9.0 years were included. Median systemic treatment lines of ICI-1 and ICI-2 were 1 (range, 1-4) and 3 (range, 2-9), respectively. ICI-based therapies used at ICI-1 and ICI-2 included ICI alone (ICI-1, n = 26, 45%; ICI-2, n = 4, 7%), dual ICI regimens (n = 1, 2%; n = 12, 21%), or ICI combined with targeted therapies/anti-VEGF (n = 31, 53%; n = 42, 72%). Most patients discontinued ICI-1 due to progression (n = 52, 90%). Objective response rate was 22% at ICI-1 and 26% at ICI-2. Responses at ICI-2 were also seen in patients who had progressive disease as best overall response at ICI-1 (n = 11/21; 52%). Median time-to-progression at ICI-1 and ICI-2 was 5.4 (95% CI 3.0-7.7) months and 5.2 (95% CI 3.3-7.0) months, respectively. Treatment-related adverse events of grade 3-4 at ICI-1 and ICI-2 were observed in 9 (16%) and 10 (17%) patients, respectively. Conclusions: ICI rechallenge was safe and resulted in a treatment benefit in a meaningful proportion of patients with HCC. These data provide a rationale for investigating ICI-based regimens in patients who progressed on first-line immunotherapy in prospective trials. Impact and implications: Therapeutic sequencing after first-line immune checkpoint inhibitor (ICI)-based therapy for advanced hepatocellular carcinoma (HCC) remains a challenge as no available second-line treatment options have been studied in immunotherapy-pretreated patients. Particularly, the role of ICI rechallenge in patients with HCC is unclear, as data from prospective trials are lacking. We investigated the efficacy and safety of ICI-based regimens in patients with HCC pretreated with immunotherapy in a retrospective, international, multicenter study. Our data provide the rationale for prospective trials investigating the role of ICI-based regimens in patients who have progressed on first-line immunotherapy.

Genetic features and therapeutic relevance of emergent circulating tumor DNA alterations in refractory non-colorectal gastrointestinal cancers.

Acquired resistance to systemic treatments is inevitable in most cancers, but the genetic basis for this in many cancer types has remained elusive due to constraints in obtaining tissue specimens longitudinally. In the management of gastrointestinal cancers, molecular profiling is conventionally performed at a single time point, although serial evaluations may yield biological insights that inform treatment decisions. We characterize genetic changes in serial liquid biopsies which provide real-time snapshots of tumor genetics and heterogeneity in refractory non-colorectal gastrointestinal cancers, and determine the clinical utility of repeat circulating tumor DNA (ctDNA) testing. In a national cohort of 449 patients with pancreatic, biliary, esophagogastric, and hepatocellular cancers, resistance to conventional therapies is broadly associated with tumor evolution. Emergent ctDNA alterations only detectable at progression occurs in 63% of patients and are frequently associated with treatment actionability. Tumor mutation burden is dynamic in cancers undergoing treatment, but is not associated with time to progression. Objective tumor responses in a case series of patients receiving treatment matched to emergent alterations show that repeat liquid biopsies may have clinical benefit by expanding treatment options in advanced gastrointestinal cancers.

Profile and Predictors of Blood Tumor Mutational Burden in Advanced Hepatocellular Carcinoma.

Advanced hepatocellular carcinoma (HCC) is responsive to immune checkpoint inhibitors, but there are currently no known biomarkers to predict treatment benefit. Blood TMB (bTMB) estimation via circulating tumor DNA (ctDNA) profiling can provide a convenient means to estimate HCC TMB. Here we provide the first landscape of bTMB in advanced HCC using a commercially available next-generation sequencing assay, show that it is approximately three times as high as matched tissue TMB, and show that bTMB correlates with NAFLD cirrhosis etiology and the presence of genomic alterations in HTERT and TP53. These results lay the foundation for subsequent studies evaluating bTMB as an immune therapy predictive biomarker in HCC.

Effect of Radiation Treatment at a High-Volume Center on Outcomes in Intermediate-Risk Prostate Cancer: An Analysis of the National Cancer Database.

OBJECTIVE: To investigate the effect of radiation treatment at a high-volume center on overall survival in men with intermediate-risk prostate cancer. METHODS: From 2004 to 2015, 430,347 patients with intermediate-risk prostate cancer were identified in the National Cancer Database. Radiation case volume (RCV) of each hospital was calculated based on number of patients treated. After excluding certain patients including those with metastatic disease, our final analysis population included 116,091 intermediate-risk prostate cancer patients receiving radiation therapy or radiation with androgen deprivation therapy. Characteristics analyzed include age, race, distance to treatment facility, Charlson-Deyo Score, and socioeconomic factors. Primary outcome was overall survival (OS). Five-year survival rates were estimated using the Kaplan-Meier method. Adjusted hazard ratios with 95% confidence intervals were computed using multivariate analysis. Cox regression and propensity score-matched analysis was performed. RESULTS: Median follow up was 63.5 months and estimated 5-year OS was 90.1% at high RCV centers and 88.2% at low RCV centers (P <.0001). Treatment at high RCV facility was associated with significantly lower mortality compared to treatment at a low RCV facility on multivariate analysis and propensity score matching analysis. The survival benefit of treatment at a high RCV facility remained when high RCV facilities were defined as those above the 80th, 90th, and 95th percentile in patient volume (P <.05). CONCLUSION: Treatment at a high radiation case volume facility is associated with improved OS in patients with radiation-treated intermediate-risk prostate cancer. This survival benefit is important to consider when choosing a treatment center for radiation therapy.

Off-label prescribing of targeted anticancer therapy at a large pediatric cancer center.

BACKGROUND: Off-label drug prescribing is common in pediatric clinical medicine, though the extent and impact of this practice in pediatric oncology has not yet been characterized. METHODS: We completed a retrospective single-institution cohort study evaluating prevalence, characteristics, and clinical outcomes of off-label prescribing of 108 FDA-approved targeted anticancer drugs in patients < 30 years old treated for cancer from 2007 to 2017. Dosing strategies were adjusted for body size and compared to FDA-approved adult dosing regimen. A composite toxicity endpoint was defined as a patient having unplanned clinic visits, emergency department visits, or unplanned hospital admissions that were at least possibly related to the off-label treatment. RESULTS: The overall prevalence of off-label use of targeted therapies was 9.2% (n = 374 patients). The prevalence increased significantly over the study period (P < .0001). Patients treated off-label were more likely to have neuro-oncology diagnoses compared to patients not treated off-label (46% vs 29%; P < .0001). Of the 108 potential agents, 38 (35%) were used by at least one patient. The median starting dose was below the FDA-approved normalized dose for 44.4% of agents. Fifteen percent of patients had a complete response while receiving off-label therapy, 38% experienced toxicity as defined, and 13% discontinued off-label therapy due to toxicity. CONCLUSIONS: In this real-world evaluation of prescribing at a large pediatric cancer center, off-label prescribing of FDA-approved targeted therapies was common, increasing in prevalence, encompassed a broad sample of targeted agents, and was tolerable. Clinicians commonly start dosing below the equivalent FDA-approved dose.