Jose Luis Perez-Gracia

Pembrolizumab versus docetaxel for previously treated, PD-L1-positive, advanced non-small-cell lung cancer (KEYNOTE-010): A randomised controlled trial

BACKGROUND Despite recent advances in the treatment of advanced non-small-cell lung cancer, there remains a need for effective treatments for progressive disease. We assessed the efficacy of pembrolizumab for patients with previously treated, PD-L1-positive, advanced non-small-cell lung cancer. METHODS We did this randomised, open-label, phase 2/3 study at 202 academic medical centres in 24 countries. Patients with previously treated non-small-cell lung cancer with PD-L1 expression on at least 1% of tumour cells were randomly assigned (1:1:1) in blocks of six per stratum with an interactive voice-response system to receive pembrolizumab 2 mg/kg, pembrolizumab 10 mg/kg, or docetaxel 75 mg/m(2) every 3 weeks. The primary endpoints were overall survival and progression-free survival both in the total population and in patients with PD-L1 expression on at least 50% of tumour cells. We used a threshold for significance of p<0.00825 (one-sided) for the analysis of overall survival and a threshold of p<0.001 for progression-free survival. This trial is registered at ClinicalTrials.gov, number NCT01905657. FINDINGS Between Aug 28, 2013, and Feb 27, 2015, we enrolled 1034 patients: 345 allocated to pembrolizumab 2 mg/kg, 346 allocated to pembrolizumab 10 mg/kg, and 343 allocated to docetaxel. By Sept 30, 2015, 521 patients had died. In the total population, median overall survival was 10.4 months with pembrolizumab 2 mg/kg, 12.7 months with pembrolizumab 10 mg/kg, and 8.5 months with docetaxel. Overall survival was significantly longer for pembrolizumab 2 mg/kg versus docetaxel (hazard ratio [HR] 0.71, 95% CI 0.58-0.88; p=0.0008) and for pembrolizumab 10 mg/kg versus docetaxel (0.61, 0.49-0.75; p<0.0001). Median progression-free survival was 3.9 months with pembrolizumab 2 mg/kg, 4.0 months with pembrolizumab 10 mg/kg, and 4.0 months with docetaxel, with no significant difference for pembrolizumab 2 mg/kg versus docetaxel (0.88, 0.74-1.05; p=0.07) or for pembrolizumab 10 mg/kg versus docetaxel (HR 0.79, 95% CI 0.66-0.94; p=0.004). Among patients with at least 50% of tumour cells expressing PD-L1, overall survival was significantly longer with pembrolizumab 2 mg/kg than with docetaxel (median 14.9 months vs 8.2 months; HR 0.54, 95% CI 0.38-0.77; p=0.0002) and with pembrolizumab 10 mg/kg than with docetaxel (17.3 months vs 8.2 months; 0.50, 0.36-0.70; p<0.0001). Likewise, for this patient population, progression-free survival was significantly longer with pembrolizumab 2 mg/kg than with docetaxel (median 5.0 months vs 4.1 months; HR 0.59, 95% CI 0.44-0.78; p=0.0001) and with pembrolizumab 10 mg/kg than with docetaxel (5.2 months vs 4.1 months; 0.59, 0.45-0.78; p<0.0001). Grade 3-5 treatment-related adverse events were less common with pembrolizumab than with docetaxel (43 [13%] of 339 patients given 2 mg/kg, 55 [16%] of 343 given 10 mg/kg, and 109 [35%] of 309 given docetaxel). INTERPRETATION Pembrolizumab prolongs overall survival and has a favourable benefit-to-risk profile in patients with previously treated, PD-L1-positive, advanced non-small-cell lung cancer. These data establish pembrolizumab as a new treatment option for this population and validate the use of PD-L1 selection. FUNDING Merck & Co.

Atezolizumab in patients with locally advanced and metastatic urothelial carcinoma who have progressed following treatment with platinum-based chemotherapy: a single-arm, multicentre, phase 2 trial

BACKGROUND Patients with metastatic urothelial carcinoma have few treatment options after failure of platinum-based chemotherapy. In this trial, we assessed treatment with atezolizumab, an engineered humanised immunoglobulin G1 monoclonal antibody that binds selectively to programmed death ligand 1 (PD-L1), in this patient population. METHODS For this multicentre, single-arm, two-cohort, phase 2 trial, patients (aged ≥18 years) with inoperable locally advanced or metastatic urothelial carcinoma whose disease had progressed after previous platinum-based chemotherapy were enrolled from 70 major academic medical centres and community oncology practices in Europe and North America. Key inclusion criteria for enrolment were Eastern Cooperative Oncology Group performance status of 0 or 1, measurable disease defined by Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1), adequate haematological and end-organ function, and no autoimmune disease or active infections. Formalin-fixed paraffin-embedded tumour specimens with sufficient viable tumour content were needed from all patients before enrolment. Patients received treatment with intravenous atezolizumab (1200 mg, given every 3 weeks). PD-L1 expression on tumour-infiltrating immune cells (ICs) was assessed prospectively by immunohistochemistry. The co-primary endpoints were the independent review facility-assessed objective response rate according to RECIST v1.1 and the investigator-assessed objective response rate according to immune-modified RECIST, analysed by intention to treat. A hierarchical testing procedure was used to assess whether the objective response rate was significantly higher than the historical control rate of 10% at an α level of 0·05. This study is registered with ClinicalTrials.gov, number NCT02108652. FINDINGS Between May 13, 2014, and Nov 19, 2014, 486 patients were screened and 315 patients were enrolled into the study. Of these patients, 310 received atezolizumab treatment (five enrolled patients later did not meet eligibility criteria and were not dosed with study drug). The PD-L1 expression status on infiltrating immune cells (ICs) in the tumour microenvironment was defined by the percentage of PD-L1-positive immune cells: IC0 (<1%), IC1 (≥1% but <5%), and IC2/3 (≥5%). The primary analysis (data cutoff May 5, 2015) showed that compared with a historical control overall response rate of 10%, treatment with atezolizumab resulted in a significantly improved RECIST v1.1 objective response rate for each prespecified immune cell group (IC2/3: 27% [95% CI 19-37], p<0·0001; IC1/2/3: 18% [13-24], p=0·0004) and in all patients (15% [11-20], p=0·0058). With longer follow-up (data cutoff Sept 14, 2015), by independent review, objective response rates were 26% (95% CI 18-36) in the IC2/3 group, 18% (13-24) in the IC1/2/3 group, and 15% (11-19) overall in all 310 patients. With a median follow-up of 11·7 months (95% CI 11·4-12·2), ongoing responses were recorded in 38 (84%) of 45 responders. Exploratory analyses showed The Cancer Genome Atlas (TCGA) subtypes and mutation load to be independently predictive for response to atezolizumab. Grade 3-4 treatment-related adverse events, of which fatigue was the most common (five patients [2%]), occurred in 50 (16%) of 310 treated patients. Grade 3-4 immune-mediated adverse events occurred in 15 (5%) of 310 treated patients, with pneumonitis, increased aspartate aminotransferase, increased alanine aminotransferase, rash, and dyspnoea being the most common. No treatment-related deaths occurred during the study. INTERPRETATION Atezolizumab showed durable activity and good tolerability in this patient population. Increased levels of PD-L1 expression on immune cells were associated with increased response. This report is the first to show the association of TCGA subtypes with response to immune checkpoint inhibition and to show the importance of mutation load as a biomarker of response to this class of agents in advanced urothelial carcinoma. FUNDING F Hoffmann-La Roche Ltd.

A clinical trial of CTLA-4 blockade with tremelimumab in patients with hepatocellular carcinoma and chronic hepatitis C

BACKGROUND & AIMS Tremelimumab is a monoclonal antibody that blocks cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), an inhibitory co-receptor that interferes with T cell activation and proliferation. The purpose of this pilot clinical trial was to test the antitumor and antiviral effect of tremelimumab in patients with hepatocellular carcinoma (HCC) and chronic hepatitis C virus (HCV) infection; and to study the safety of its administration to cirrhotic patients. METHODS Tremelimumab at a dose of 15 mg/kg IV every 90 days was administered until tumor progression or severe toxicity. Twenty patients were assessable for toxicity and viral response and 17 were assessable for tumor response. Most patients were in the advanced stage and 43% had an altered liver function (Child-Pugh class B). RESULTS A good safety profile was recorded and no patient needed steroids because of severe immune-mediated adverse events. Some patients had a transient albeit intense elevation of transaminases after the first dose, but not following subsequent cycles. Partial response rate was 17.6% and disease control rate was 76.4%. Time to progression was 6.48 months (95% CI 3.95-9.14). A significant drop in viral load was observed while new emerging variants of the hypervariable region 1 of HCV replaced the predominant variants present before therapy, particularly in those patients with a more prominent drop in viral load. This antiviral effect was associated with an enhanced specific anti-HCV immune response. CONCLUSIONS Tremelimumab safety profile and antitumor and antiviral activity, in patients with advanced HCC developed on HCV-induced liver cirrhosis, support further investigation.

Direct Effects of Type I Interferons on Cells of the Immune System

Type I interferons (IFN-I) are well-known inducers of tumor cell apoptosis and antiangiogenesis via signaling through a common receptor interferon alpha receptor (IFNAR). IFNAR induces the Janus activated kinase–signal transducer and activation of transcription (JAK-STAT) pathway in most cells, along with other biochemical pathways that may differentially operate, depending on the responding cell subset, and jointly control a large collection of genes. IFNs-I were found to systemically activate natural killer (NK) cell activity. Recently, mouse experiments have shown that IFNs-I directly activate other cells of the immune system, such as antigen-presenting dendritic cells (DC) and CD4 and CD8 T cells. Signaling through the IFNAR in T cells is critical for the acquisition of effector functions. Cross-talk between IFNAR and the pathways turned on by other surface lymphocyte receptors has been described. Importantly, IFNs-I also increase antigen presentation of the tumor cells to be recognized by T lymphocytes. These IFN-driven immunostimulatory pathways offer opportunities to devise combinatorial immunotherapy strategies. Clin Cancer Res; 17(9); 2619–27. ©2011 AACR.

Clinical Development of Immunostimulatory Monoclonal Antibodies and Opportunities for Combination

Immune system responses are under the control of extracellular biomolecules, which express functions in receptors present on the surface of cells of the immune system, and thus are amenable to be functionally modulated by monoclonal antibodies. Some of these mechanisms are activating and dictate whether the response ensues, while others play the role of powerful repressors. Antagonist antibodies acting on such repressors result in enhanced immune responses, a goal that is also achieved with agonist antibodies acting on the activating receptors. With these simple logics, a series of therapeutic agents are under clinical development and one of them directed at the CTL-associated antigen 4 (CTLA-4) inhibitory receptor (ipilimumab) has been approved for the treatment of metastatic melanoma. The list of antagonist agents acting on repressors under development includes anti–CTLA-4, anti–PD-1, anti–PD-L1 (B7-H1), anti-KIR, and anti–TGF-β. Agonist antibodies currently being investigated in clinical trials target CD40, CD137 (4-1BB), CD134 (OX40), and glucocorticoid-induced TNF receptor (GITR). A blossoming preclinical pipeline suggests that other active targets will also be tested in patients in the near future. All of these antibodies are being developed as conventional monoclonal immunoglobulins, but other engineered antibody formats or RNA aptamers are under preclinical scrutiny. The “dark side” of these immune interventions is that they elicit autoimmune/inflammatory reactions that can be severe in some patients. A critical and, largely, pending subject is to identify reliable predictive biomarkers both for efficacy and immune toxicity. Preclinical and early clinical studies indicate a tremendous potential to further improve efficacy, using combinations from among these new agents that frequently act in a synergistic fashion. Combinations with other more conventional means of treatment such as radiotherapy, chemotherapy, or cancer vaccines also hold much promise. Clin Cancer Res; 19(5); 997–1008. ©2013 AACR.

Influence of bevacizumab, sunitinib and sorafenib as single agents or in combination on the inhibitory effects of VEGF on human dendritic cell differentiation from monocytes

Vascular endothelial growth factor (VEGF) inhibits differentiation and maturation of dendritic cells (DC), suggesting a potential immunosuppressive role for this proangiogenic factor. Bevacizumab, sorafenib and sunitinib target VEGF-mediated angiogenesis and are active against several types of cancer, but their effects on the immune system are poorly understood. In this study, VEGF and supernatants of renal carcinoma cell lines cultured under hypoxia were found to alter the differentiation of human monocytes to DC. Resulting DC showed impaired activity, as assessed by the alloreactive mixed T-lymphocyte reaction. Bevacizumab and sorafenib, but not sunitinib, reversed the inhibitory effects of VEGF, but not of those mediated by tumour supernatants. Dendritic cells matured under the influence of VEGF expressed less human leukocyte antigen-DR (HLA-DR) and CD86, and this effect was restored by bevacizumab and sorafenib. Finally, tumour-cell supernatants decreased interleukin-12 (IL-12) production by mature DC, and such inhibition was not restored by any of the tested drugs, delivered either as single agents or in combination. The deleterious effects of tumour-cell supernatants were mainly mediated by thermostable molecules distinct from VEGF. These results indicate that inhibition of the differentiation of monocytes to DC is a multifactorial effect, and that they support the development of combinations of angiogenesis inhibitors with immunological modulators.

Agonist Anti-CD137 mAb Act on Tumor Endothelial Cells to Enhance Recruitment of Activated T Lymphocytes

Agonist monoclonal antibodies (mAb) to the immune costimulatory molecule CD137, also known as 4-1BB, are presently in clinical trials for cancer treatment on the basis of their costimulatory effects on primed T cells and perhaps other cells of the immune system. Here we provide evidence that CD137 is selectively expressed on the surface of tumor endothelial cells. Hypoxia upregulated CD137 on murine endothelial cells. Treatment of tumor-bearing immunocompromised Rag(-/-) mice with agonist CD137 mAb did not elicit any measurable antiangiogenic effects. In contrast, agonist mAb stimulated tumor endothelial cells, increasing cell surface expression of the adhesion molecules intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, and E-selectin. When adoptively transferred into mice, activated T lymphocytes derived from CD137-deficient animals entered more avidly into tumor tissue after treatment with agonist mAb. This effect could be neutralized with anti-ICAM-1 and anti-VCAM-1 blocking antibodies. Thus, stimulation of CD137 not only enhanced T-cell activation but also augmented their trafficking into malignant tissue, through direct actions on the blood vessels that irrigate the tumor. Our findings identify an additional mechanism of action that can explain the immunotherapeutic effects of agonist CD137 antibodies.

Quantitative Cell-Free Circulating BRAFV600E Mutation Analysis by Use of Droplet Digital PCR in the Follow-up of Patients with Melanoma Being Treated with BRAF Inhibitors

BACKGROUND Around 50% of cutaneous melanomas harbor the BRAF(V600E) mutation and can be treated with BRAF inhibitors. DNA carrying this mutation can be released into circulation as cell-free BRAF(V600E) (cfBRAF(V600E)). Droplet digital PCR (ddPCR) is an analytically sensitive technique for quantifying small concentrations of DNA. We studied the plasma concentrations of cfBRAF(V600E) by ddPCR in patients with melanoma during therapy with BRAF inhibitors. METHODS Plasma concentrations of cfBRAF(V600E) were measured in 8 controls and 20 patients with advanced melanoma having the BRAF(V600E) mutation during treatment with BRAF inhibitors at baseline, first month, best response, and progression. RESULTS The BRAF(V600E) mutation was detected by ddPCR even at a fractional abundance of 0.005% in the wild-type gene. Agreement between tumor tissue BRAF(V600E) and plasma cfBRAF(V600E) was 84.3%. Baseline cfBRAF(V600E) correlated with tumor burden (r = 0.742, P < 0.001). cfBRAF(V600E) concentrations decreased significantly at the first month of therapy (basal median, 216 copies/mL; Q1-Q3, 27-647 copies/mL; first response median, 0 copies/mL; Q1-Q3, 0-49 copies/mL; P < 0.01) and at the moment of best response (median, 0 copies/mL; Q1-Q3, 0-33 copies/mL; P < 0.01). At progression, there was a significant increase in the concentration of cfBRAF(V600E) compared with best response (median, 115 copies/mL; Q1-Q3, 3-707 copies/mL; P = 0.013). Lower concentrations of basal cfBRAF(V600E) were significantly associated with longer overall survival and progression-free survival (27.7 months and 9 months, respectively) than higher basal concentrations (8.6 months and 3 months, P < 0.001 and P = 0.024, respectively). CONCLUSIONS cfBRAF(V600E) quantification in plasma by ddPCR is useful as a follow-up to treatment response in patients with advanced melanoma.

Phase II study of sunitinib as first-line treatment of urothelial cancer patients ineligible to receive cisplatin-based chemotherapy: baseline interleukin-8 and tumor contrast enhancement as potential predictive factors of activity

BACKGROUND A strong rationale supports the role of antiangiogenic drugs in urothelial cancer. This trial was designed to assess the activity of sunitinib as first-line treatment in patients with metastatic urothelial cancer ineligible for cisplatin and to explore molecular and imaging variables predictive of clinical benefit. PATIENTS AND METHODS This was a multicenter phase II trial with sunitinib 50 mg daily in 4/2-week schedule. Eligibility criteria were as follows: creatinine clearance 30-60 ml/min, Eastern Cooperative Oncology Group Pperformance Sstatus of one or less, and adequate hepatic and hematologic function. Twelve circulating cytokines were evaluated at baseline and sequentially using Luminex xMAP(®) (Austin, TX). Baseline and treatment-related changes in perfusion were evaluated in a patient subgroup using contrast-enhanced computed tomography. RESULTS On intention-to-treat analysis, 38 patients showed 3 (8%) partial responses (PRs) and 19 (50%) presented with stable disease (SD), 17 (45%) of them ≥3 months. Clinical benefit (PR + SD) was 58%. Median time to progression (TTP) was 4.8 months and median overall survival 8.1 months. Toxicity was consistent with previous reports for sunitinib. Low interleukin-8 (IL-8) baseline levels were significantly associated with increased TTP. Baseline tumor contrast enhancement with >40 Hounsfield units was associated with clinical benefit. CONCLUSIONS This study highlights the potential role of the angiogenic pathway as a therapy target in urothelial cancer. Baseline IL-8 serum levels and contrast enhancement of lesions warrant further study.

Multi-layered action mechanisms of CD137 (4-1BB)-targeted immunotherapies

CD137 (also known as 4-1BB) is a surface co-stimulatory glycoprotein originally described as present on activated T lymphocytes. Artificial stimulation of this molecule with monoclonal antibodies or other agonist moieties therapeutically augments the cellular immune response against tumors, regardless of the absence of CD137 on tumor cells. These pharmacological agents, when administered systemically, surpass the immune effects of the membrane-bound natural ligand (CD137 or 4-1BB ligand), the activity of which is confined to cell-to-cell interactions. Greater affinity and broader distribution of the CD137 pharmacological agonists cause much more intense receptor crosslinking and stronger intracellular signals than the natural ligand. Target engagement on a variety of immune cell types such as T, natural killer and dendritic cells and on tumor vessels could switch on multiple mechanisms of action. As an agonist, anti-CD137 monoclonal antibody has entered Phase II clinical trials; elucidation of the mechanisms behind the antitumor efficacy requires further research in mice and patients to understand and rationally combine these new treatments.