Matthew A. Gubens

Pembrolizumab for the Treatment of Non–Small-Cell Lung Cancer

BACKGROUND We assessed the efficacy and safety of programmed cell death 1 (PD-1) inhibition with pembrolizumab in patients with advanced non-small-cell lung cancer enrolled in a phase 1 study. We also sought to define and validate an expression level of the PD-1 ligand 1 (PD-L1) that is associated with the likelihood of clinical benefit. METHODS We assigned 495 patients receiving pembrolizumab (at a dose of either 2 mg or 10 mg per kilogram of body weight every 3 weeks or 10 mg per kilogram every 2 weeks) to either a training group (182 patients) or a validation group (313 patients). We assessed PD-L1 expression in tumor samples using immunohistochemical analysis, with results reported as the percentage of neoplastic cells with staining for membranous PD-L1 (proportion score). Response was assessed every 9 weeks by central review. RESULTS Common side effects that were attributed to pembrolizumab were fatigue, pruritus, and decreased appetite, with no clear difference according to dose or schedule. Among all the patients, the objective response rate was 19.4%, and the median duration of response was 12.5 months. The median duration of progression-free survival was 3.7 months, and the median duration of overall survival was 12.0 months. PD-L1 expression in at least 50% of tumor cells was selected as the cutoff from the training group. Among patients with a proportion score of at least 50% in the validation group, the response rate was 45.2%. Among all the patients with a proportion score of at least 50%, median progression-free survival was 6.3 months; median overall survival was not reached. CONCLUSIONS Pembrolizumab had an acceptable side-effect profile and showed antitumor activity in patients with advanced non-small-cell lung cancer. PD-L1 expression in at least 50% of tumor cells correlated with improved efficacy of pembrolizumab. (Funded by Merck; KEYNOTE-001 ClinicalTrials.gov number, NCT01295827.).

Carboplatin and pemetrexed with or without pembrolizumab for advanced, non-squamous non-small-cell lung cancer: a randomised, phase 2 cohort of the open-label KEYNOTE-021 study

BACKGROUND Limited evidence exists to show that adding a third agent to platinum-doublet chemotherapy improves efficacy in the first-line advanced non-small-cell lung cancer (NSCLC) setting. The anti-PD-1 antibody pembrolizumab has shown efficacy as monotherapy in patients with advanced NSCLC and has a non-overlapping toxicity profile with chemotherapy. We assessed whether the addition of pembrolizumab to platinum-doublet chemotherapy improves efficacy in patients with advanced non-squamous NSCLC. METHODS In this randomised, open-label, phase 2 cohort of a multicohort study (KEYNOTE-021), patients were enrolled at 26 medical centres in the USA and Taiwan. Patients with chemotherapy-naive, stage IIIB or IV, non-squamous NSCLC without targetable EGFR or ALK genetic aberrations were randomly assigned (1:1) in blocks of four stratified by PD-L1 tumour proportion score (<1% vs ≥1%) using an interactive voice-response system to 4 cycles of pembrolizumab 200 mg plus carboplatin area under curve 5 mg/mL per min and pemetrexed 500 mg/m2 every 3 weeks followed by pembrolizumab for 24 months and indefinite pemetrexed maintenance therapy or to 4 cycles of carboplatin and pemetrexed alone followed by indefinite pemetrexed maintenance therapy. The primary endpoint was the proportion of patients who achieved an objective response, defined as the percentage of patients with radiologically confirmed complete or partial response according to Response Evaluation Criteria in Solid Tumors version 1.1 assessed by masked, independent central review, in the intention-to-treat population, defined as all patients who were allocated to study treatment. Significance threshold was p<0·025 (one sided). Safety was assessed in the as-treated population, defined as all patients who received at least one dose of the assigned study treatment. This trial, which is closed for enrolment but continuing for follow-up, is registered with ClinicalTrials.gov, number NCT02039674. FINDINGS Between Nov 25, 2014, and Jan 25, 2016, 123 patients were enrolled; 60 were randomly assigned to the pembrolizumab plus chemotherapy group and 63 to the chemotherapy alone group. 33 (55%; 95% CI 42-68) of 60 patients in the pembrolizumab plus chemotherapy group achieved an objective response compared with 18 (29%; 18-41) of 63 patients in the chemotherapy alone group (estimated treatment difference 26% [95% CI 9-42%]; p=0·0016). The incidence of grade 3 or worse treatment-related adverse events was similar between groups (23 [39%] of 59 patients in the pembrolizumab plus chemotherapy group and 16 [26%] of 62 in the chemotherapy alone group). The most common grade 3 or worse treatment-related adverse events in the pembrolizumab plus chemotherapy group were anaemia (seven [12%] of 59) and decreased neutrophil count (three [5%]); an additional six events each occurred in two (3%) for acute kidney injury, decreased lymphocyte count, fatigue, neutropenia, and sepsis, and thrombocytopenia. In the chemotherapy alone group, the most common grade 3 or worse events were anaemia (nine [15%] of 62) and decreased neutrophil count, pancytopenia, and thrombocytopenia (two [3%] each). One (2%) of 59 patients in the pembrolizumab plus chemotherapy group experienced treatment-related death because of sepsis compared with two (3%) of 62 patients in the chemotherapy group: one because of sepsis and one because of pancytopenia. INTERPRETATION Combination of pembrolizumab, carboplatin, and pemetrexed could be an effective and tolerable first-line treatment option for patients with advanced non-squamous NSCLC. This finding is being further explored in an ongoing international, randomised, double-blind, phase 3 study. FUNDING Merck & Co.

Pembrolizumab cutaneous adverse events and their association with disease progression

IMPORTANCE Immunomodulatory anticancer drugs, such as the anti-programmed death-1 drug pembrolizumab, have shown promising results in trials, and more patients will receive such treatments. Little is known about cutaneous adverse events (AEs) caused by these drugs and their possible correlation with treatment response. OBJECTIVE To describe the frequency and spectrum of cutaneous AEs linked with pembrolizumab and their possible correlation with treatment response. DESIGN, SETTING, AND PARTICIPANTS A single-institution, retrospective medical record review was conducted of patients with cancer who were treated with pembrolizumab from March 1, 2011, to May 28, 2014. The review comprised 83 consecutive patients who were enrolled in 2 clinical trials, received at least 1 dose of pembrolizumab, and had at least 1 follow-up visit. Patients were grouped according to the following therapeutic regimen for pembrolizumab: 43 received 10 mg/kg every 3 weeks, 24 received 10 mg/kg every 2 weeks, and 16 received 2 mg/kg every 3 weeks. Sixty-six patients were treated for melanoma, 15 patients for lung cancer, 1 patient for prostate cancer, and 1 patient for Merkel cell carcinoma. Median follow-up was 15 weeks (range, 2-105 weeks). The analysis was conducted from March 1 to September 30, 2014. MAIN OUTCOMES AND MEASURES Occurrence, severity, and type of cutaneous AEs, as well as disease progression and response to pembrolizumab treatment. RESULTS Thirty-five patients (42%) developed cutaneous AEs attributed to pembrolizumab. The most common cutaneous AEs were macular papular eruption (24 [29%]), pruritus (10 [12%]), and hypopigmentation (7 [8%]). All 7 patients who developed hypopigmentation were treated for melanoma. Survival analyses showed that patients who developed cutaneous AEs had significantly longer progression-free intervals in all 3 groups (pembrolizumab, 10 mg/kg, every 3 weeks, P = .001; pembrolizumab, 10 mg/kg, every 2 weeks, P = .003; pembrolizumab, 2 mg/kg, every 3 weeks, P = .009) compared with patients who did not develop cutaneous AEs. CONCLUSIONS AND RELEVANCE Pembrolizumab therapy was associated with cutaneous AEs in 42% of patients. The development of cutaneous AEs, especially of hypopigmentation in patients with melanoma, could point toward better treatment response.

Long-Term Survivors of Gastric Cancer: A California Population-Based Study

PURPOSE In the United States, gastric cancer is rapidly fatal with a 25% 5-year survival. Of the few patients who survive, little is known about their demographic, clinical, and tumor characteristics. PATIENTS AND METHODS Data regarding all cases of gastric and gastroesophageal junction (GEJ) adenocarcinoma diagnosed in California between 1988 and 2005 were obtained from the California Cancer Registry, a member of the National Cancer Institutes Surveillance, Epidemiology, and End Results (SEER) program. A Cox proportional hazards model was constructed to understand the independent relationships of patient demographic, disease, and treatment factors with survival. RESULTS We identified 47,647 patients diagnosed with gastric or GEJ cancer. Of those, only 9,325 (20%) survived at least 3 years. Variables associated with longer survival were localized stage (hazard ratio [HR], 0.20), surgery with diagnosis in 2002 or later (HR, 0.34), surgery with diagnosis in 2001 or before (0.37), regional stage (HR, 0.53), chemotherapy (HR, 0.56), intestinal histology (HR, 0.74), well- or moderately differentiated tumors (HR, 0.76), radiation (HR, 0.80), Asian/Pacific Islander race (HR, 0.81), treatment at an academic hospital (HR, 0.85), fundus/body/antrum location (HR, 0.90), highest socioeconomic status quintile (HR, 0.91), female sex (HR, 0.92), Hispanic race (HR, 0.92), and hospital size more than 150 beds (HR, 0.94). Kaplan-Meier curves showed longer median disease-specific survival (DSS) in patients with tumors originating in the fundus/body/antrum compared with esophagus/cardia (13.4 v 10.8 months). Intestinal histology had significantly longer median DSS (28.9 months) compared with other (11.0 months) or diffuse (10.1 months) histology. CONCLUSION Patients who survive gastric and GEJ cancer more than 3 years after diagnosis have demographic and pathologic characteristics distinct from those who do not survive.

A Phase I Dose Escalation and Expansion Study of the Anticancer Stem Cell Agent Demcizumab (Anti-DLL4) in Patients with Previously Treated Solid Tumors

Purpose: This phase I trial evaluated the safety, pharmacokinetics, and pharmacodynamics of demcizumab (OMP-21M18), a humanized IgG2 mAb targeting the Notch ligand DLL4 in adult patients with advanced malignancies. Experimental Design: Standard 3+3 design, with demcizumab 0.5, 1, 2.5, or 5 mg/kg weekly or 2.5, 5, or 10 mg/kg every other week, with an expansion cohort at 10 mg/kg every other week. Dose-limiting toxicities (DLT) were assessed during the first 28 days. Results: Fifty-five patients received demcizumab (15 weekly, 18 every other week, 21 expansion cohort, 1 loading dose). No more than one DLT was seen at any dose level. The MTD was not reached for either schedule. Treatment-related adverse events occurring in >10% of patients were hypertension or blood pressure increased (47%), fatigue (31%), anemia (22%), headache (20%), nausea (13%), hypoalbuminemia (11%), dizziness (11%), and dyspnea (11%). One patient dosed at 2.5 mg/kg developed reversible right-sided heart failure after 63 days on treatment and 4 dosed at 10 mg/kg developed congestive heart failure after ≥98 days on treatment. Five patients were hospitalized with bleeding episodes (2 episodes of tumor-associated bleeding). Sixteen of 25 (64%) evaluable patients at 10 mg/kg had evidence of stabilization of disease or response. Conclusion: Demcizumab was generally well tolerated at doses ≤5 mg weekly with disease stabilization and decreases in tumor size demonstrating antitumor activity. Hypertension was the most common adverse event that was clearly related to treatment. Prolonged administration was associated with an increased risk of congestive heart failure. Clin Cancer Res; 20(24); 6295–303. ©2014 AACR.

Abstract CT105: MK-3475 (anti-PD-1 monoclonal antibody) for non-small cell lung cancer (NSCLC): Antitumor activity and association with tumor PD-L1 expression

Background: MK-3475, a humanized monoclonal IgG4 antibody against PD-1, has demonstrated durable antitumor activity in NSCLC and melanoma. Preliminary data presented at the 2013 World Congress of Lung Cancer showed a relationship between tumor PD-L1 expression and overall response to MK-3475. Here, we present updated data on tumor PD-L1 expression and its relationship with overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Methods: In a phase I study, 38 previously treated NSCLC patients received MK-3475 10 mg/kg Q3W. Tumor response was assessed every 9 weeks by immune-related response criteria (irRC) per investigator review and by RECIST v1.1 per independent radiologic review. A new tumor biopsy performed within 60 days prior to the first dose of MK-3475 was required. Tumor PD-L1 expression was assessed by IHC. A potential cut point for PD-L1 expression was determined by the Youden Index from a receiver operating characterstics curve developed from the investigators’ irRC assessments. Results: Confirmed ORR for the entire cohort of 38 patients per investigators’ irRC assessments was 24%, median PFS was 9 weeks, and median OS was 51 weeks. PD-L1 IHC score was above a potential cut point in 9 patients and below a potential cut point in 22 patients; tumor was not submitted for or staining was not evaluable in 7 patients. Significant associations between tumor PD-L1 expression and ORR, PFS, and OS were observed (Table). Conclusions: Tumor PD-L1 expression levels were associated with tumor response, PFS, and OS in patients with NSCLC treated with MK-3475. The preliminary finding of minimal anti-tumor activity in patients whose tumors express low levels of PD-L1 suggests that PD-L1 is an important biomarker for patients with NSCLC treated with MK-3475. Citation Format: Leena Gandhi, Ani Balmanoukian, Rina Hui, Omid Hamid, Naiyer A. Rizvi, Natasha Leighl, Matthew Gubens, Jonathan W. Goldman, Gregory M. Lubiniecki, Kenneth Emancipator, Marisa Dolled-Filhart, Jared K. Lunceford, Michelle Niewood, Kevin Gergich, Edward B. Garon. MK-3475 (anti-PD-1 monoclonal antibody) for non-small cell lung cancer (NSCLC): Antitumor activity and association with tumor PD-L1 expression. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT105. doi:10.1158/1538-7445.AM2014-CT105

Systematic evaluation of pembrolizumab dosing in patients with advanced non-small-cell lung cancer

BACKGROUND In the phase I KEYNOTE-001 study, pembrolizumab demonstrated durable antitumor activity in patients with advanced non-small-cell lung cancer (NSCLC). We sought to characterize the relationship between pembrolizumab dose, exposure, and response to define an effective dose for these patients. PATIENTS AND METHODS Patients received pembrolizumab 2 mg/kg every 3 weeks (Q3W) (n = 55), 10 mg/kg Q3W (n = 238), or 10 mg/kg Q2W (n = 156). Response (RECIST v1.1) was assessed every 9 weeks. The relationship between the estimated pembrolizumab area under the concentration-time curve at steady state over 6 weeks (AUCss-6weeks) and the longitudinal change in tumor size (sum of longest diameters) was analyzed by regression and non-linear mixed effects modeling. This model was simultaneously fit to all tumor size data, then used to simulate response rates, normalizing the trial data across dose for prognostic covariates (tumor PD-L1 expression and EGFR mutation status). The exposure-safety relationship was assessed by logistic regression of pembrolizumab AUCss-6weeks versus occurrence of adverse events (AEs) of interest based on their immune etiology. RESULTS Overall response rates were 15% [95% confidence interval (CI) 7%-28%] at 2 mg/kg Q3W, 25% (18%-33%) at 10 mg/kg Q3W, and 21% (95% CI 14%-30%) at 10 mg/kg Q2W. Regression analyses of percentage change from baseline in tumor size versus AUCss-6weeks indicated a flat relationship (regression slope P > 0.05). Simulations showed the exposure-response relationship to be similarly flat, thus indicating that the lowest evaluated dose of 2 mg/kg Q3W to likely be at or near the efficacy plateau. Exposure-safety analysis showed the AE incidence to be similar among the clinically tested doses. CONCLUSIONS No significant exposure dependency on efficacy or safety was identified for pembrolizumab across doses of 2-10 mg/kg. These results support the use of a 2 mg/kg Q3W dosage in patients with previously treated, advanced NSCLC. CLINICALTRIALSGOV REGISTRY NCT01295827.

Prolonged survival of patients with non-small-cell lung cancer with leptomeningeal carcinomatosis in the modern treatment era.

INTRODUCTION Leptomeningeal carcinomatosis (LM) is a severe complication of non-small-cell lung cancer (NSCLC) historically associated with poor prognosis. New chemotherapeutic and targeted treatments could potentially affect the natural history of LM. PATIENTS AND METHODS Patients with a pathologic diagnosis of NSCLC with LM treated at Stanford between 2003 and 2011 were identified via institutional databases and medical records. LM was defined by cerebrospinal fluid (CSF) that was positive for malignant cells or by LM enhancement on magnetic resonance imaging with gadolinium contrast. Retrospective, landmark analyses were performed to estimate survival. Statistical analyses were performed using SAS Enterprise Guide, version 4.3. RESULTS LM was identified in 30 patients. All cases were adenocarcinoma; 60% of patients had a known or suspected driver mutation. The mean age was 58 years. Of the 30 patients, 67% were women; 70% were nonsmokers; 27% initially presented with LM; 84% received systemic treatment at or after development of LM; and 53% of these patients received modern systemic therapy for their LM, defined as a regimen containing pemetrexed, bevacizumab, or a tyrosine kinase inhibitor. Mean overall survival after LM diagnosis was 6 months (95% CI, 3-12). Patients who received modern systemic therapy for LM had decreased hazard of death (hazard ratio [HR], 0.24; P = .007). CONCLUSION In this retrospective, single-institution analysis, median survival with LM was higher compared with historical experience. Patients who received modern systemic therapy for their LM had particularly good outcomes. These data provide evidence for improving survival outcomes in the modern treatment era for this difficult-to-treat complication.

Liver Metastasis and Treatment Outcome with Anti-PD-1 Monoclonal Antibody in Patients with Melanoma and NSCLC

The association between metastatic site and responses to anti-PD-1 immunotherapy was explored In both melanoma and lung cancer. Liver metastasis was associated with worse outcome and CD8+ T cell-poor tumors, suggesting a potential mechanism for the outcomes. We explored the association between liver metastases, tumor CD8+ T-cell count, and response in patients with melanoma or lung cancer treated with the anti-PD-1 antibody, pembrolizumab. The melanoma discovery cohort was drawn from the phase I Keynote 001 trial, whereas the melanoma validation cohort was drawn from Keynote 002, 006, and EAP trials and the non–small cell lung cancer (NSCLC) cohort from Keynote 001. Liver metastasis was associated with reduced response and shortened progression-free survival [PFS; objective response rate (ORR), 30.6%; median PFS, 5.1 months] compared with patients without liver metastasis (ORR, 56.3%; median PFS, 20.1 months) P ≤ 0.0001, and confirmed in the validation cohort (P = 0.0006). The presence of liver metastasis significantly increased the likelihood of progression (OR, 1.852; P < 0.0001). In a subset of biopsied patients (n = 62), liver metastasis was associated with reduced CD8+ T-cell density at the invasive tumor margin (liver metastasis+ group, n = 547 ± 164.8; liver metastasis− group, n = 1,441 ± 250.7; P < 0.016). A reduced response rate and shortened PFS was also observed in NSCLC patients with liver metastasis [median PFS, 1.8 months; 95% confidence interval (CI), 1.4–2.0], compared with those without liver metastasis (n = 119, median PFS, 4.0 months; 95% CI, 2.1–5.1), P = 0.0094. Thus, liver metastatic patients with melanoma or NSCLC that had been treated with pembrolizumab were associated with reduced responses and PFS, and liver metastases were associated with reduced marginal CD8+ T-cell infiltration, providing a potential mechanism for this outcome. Cancer Immunol Res; 5(5); 417–24. ©2017 AACR.

Evolution and clinical impact of co-occurring genetic alterations in advanced-stage EGFR-mutant lung cancers

A widespread approach to modern cancer therapy is to identify a single oncogenic driver gene and target its mutant-protein product (for example, EGFR-inhibitor treatment in EGFR-mutant lung cancers). However, genetically driven resistance to targeted therapy limits patient survival. Through genomic analysis of 1,122 EGFR-mutant lung cancer cell-free DNA samples and whole-exome analysis of seven longitudinally collected tumor samples from a patient with EGFR-mutant lung cancer, we identified critical co-occurring oncogenic events present in most advanced-stage EGFR-mutant lung cancers. We defined new pathways limiting EGFR-inhibitor response, including WNT/β-catenin alterations and cell-cycle-gene (CDK4 and CDK6) mutations. Tumor genomic complexity increases with EGFR-inhibitor treatment, and co-occurring alterations in CTNNB1 and PIK3CA exhibit nonredundant functions that cooperatively promote tumor metastasis or limit EGFR-inhibitor response. This study calls for revisiting the prevailing single-gene driver-oncogene view and links clinical outcomes to co-occurring genetic alterations in patients with advanced-stage EGFR-mutant lung cancer.