Combined Nivolumab and Ipilimumab or Monotherapy in Untreated Melanoma

Are there, or shall we discover, biomarkers to guide PD-1 inhibition?

Paolo A Ascierto and Ramon A de Mello speak to Ellen Clarke, Commissioning Editor Despite the recent success of PD-1/PD-L1-directed immunotherapy in a number of different malignancies, there are currently no effective biomarkers available to predict patient response to treatment. This question is particularly important because these immunotherapy agents are expensive and have significant toxicity profiles. Early data are emerging on biomarkers such as PD-L1 expression; however, it is clear that further studies are needed to identify alternative biomarkers and to improve understanding of the host immune system and tumor microenvironment. In a panel interview Paolo Ascierto and Ramon de Mello discuss this important clinical question.

Characterisation and management of dermatologic adverse events to agents targeting the PD-1 receptor

BACKGROUND

Dermatologic adverse events (AEs) are some of the most frequently observed toxicities of immune-checkpoint inhibitor therapy, but they have received little attention. The drugs, pembrolizumab and nivolumab are recently approved inhibitors of the programmed death (PD)-1 receptor that have overlapping AE profiles however, the incidence, relative risk (RR), and clinico-morphological pattern of the associated dermatologic AEs are not known.

METHODS

We conducted a systematic review of the literature, and performed a meta-analysis of dermatologic AEs observed with the use of pembrolizumab and nivolumab in cancer patients. An electronic search was conducted using the PubMed, and Web of Science, and on the American Society of Clinical Oncology and European Society for Medical Oncology meeting abstracts' libraries for potentially relevant oncology trials, that employed the drugs at Food and Drug Administration-approved doses and reported dermatologic AEs. The incidence, RR and 95% confidence intervals were calculated using either random- or fixed-effects models based on the heterogeneity of included studies. The clinical presentation, histology of affected skin areas, and management strategies (based on institutional experience), are also presented.

RESULTS

Rash, pruritus and vitiligo were found to be the most frequently reported dermatologic AEs. The calculated incidence of all-grade rash with pembrolizumab and nivolumab was 16.7% (RR = 2.6) and 14.3% (RR = 2.5), respectively. Other significant all-grade AEs included pruritus (pembrolizumab: incidence, 20.2% [RR = 49.9]; nivolumab: incidence, 13.2% [RR = 34.5]) and vitiligo (pembrolizumab: incidence, 8.3% [RR = 17.5]; nivolumab: 7.5% [RR = 14.6]). Interestingly, all the vitiligo events were reported in trials investigating melanoma. The RR for developing dermatologic AEs in general, was 2.95 with pembrolizumab, and 2.3 with nivolumab.

CONCLUSION

We found that pembrolizumab and nivolumab are both associated with dermatologic AEs, primarily low-grade rash, pruritus, and vitiligo, which are reminiscent of those seen with ipilimumab. Knowledge of these findings is critical for optimal care, maintaining dose intensity, and health-related quality of life in cancer patients receiving PD-1 inhibitors.

Adjuvant treatment for stage III melanoma in the era of targeted medicine and immunotherapy

The accelerated development in the treatment of metastatic melanoma, both in molecular targeted therapy and immunotherapy, is already starting to impact on adjuvant therapy in stage III melanoma. Following the approval of ipilimumab for adjuvant therapy in melanoma, clinical trials assessing other checkpoint modulators and MAPK pathway inhibitors as adjuvant treatments for melanoma are currently ongoing. As results from these trials mature in the next few years, a change in the landscape of adjuvant treatment for melanoma is expected, resulting in new challenges in treatment decisions such as optimizing patients selection through predictive and prognostic biomarkers, and management of treatment related adverse events, in particular immune related toxicities.

Immune checkpoint inhibitors side effects and management

The next decade in cancer therapy will be marked by the expansion of immunotherapies, namely immune checkpoint inhibitors. The increasing number and combination of checkpoint inhibitors and the variety of their mechanisms of action and indications will most likely multiply the side effects associated with these therapies and make their management more complicated and diversified. Given the growing rate of approval of different checkpoint inhibitors in different cancers in multiple settings, a review summarizing the major side effects of the new agents in use today and their management seems to be appropriate. Highlighting these adverse events and their management in a single review might help the daily practice of the physicians and consequently contribute the patient's safety and quality of life.

Cancer tolerance, resistance, pathogenicity and virulence: deconstructing the disease state

Immunologists have recently taken note of the fact that a host not only resists infection, but also exhibits a capacity to manage the pathology associated with such infection – a concept referred to as tolerance. Here we explore how the tolerance/resistance (T/R) framework can be implemented within an oncological context and explore a number of implications. In particular, the T/R framework distinguishes between pathology manifesting from extensive tumor burden, versus cancers intrinsically expressing a more pathogenic phenotype. Consequently, the T/R framework provides novel methodology in studying the nature of cancer pathology and for marker identification. Additionally, this framework may aid in redefining the therapeutic end point under suitable circumstances: establishing cancer as a chronic, manageable disease.

[Immunotherapy of head and neck tumors: Highlights of the ASCO Meeting 2015]

BACKGROUND

In recent years, new immunotherapeutic drugs have become available: the so-called immune checkpoint modulators. With these drugs, unprecedented treatment results have been achieved in different malignant diseases; primarily malignant melanoma, but also in various other malignomas. These achievements have revolutionized the oncologic treatment landscape. This quickly expanding research field, driven by revolutionary treatment results, has put immunotherapy in the focus of attention.

OBJECTIVE

Due to rapid developments in the field of immunotherapy, this article aims at introducing, illustrating, and summarizing the field of modern immunotherapy, based on recently presented clinical data from the Annual Meeting of the American Society of Clinical Oncology (ASCO) 2015.

MATERIALS AND METHODS

The most important ASCO Meeting 2015 immunotherapy trials for head and neck squamous cell carcinoma (HNSCC) were identified, summarized, and discussed with respect to the current state of research.

RESULTS

The oncologic landscape of clinical trials is currently dominated by the new immune checkpoint modulating drugs. Also for HNSCC, a variety of clinical trials and substances are under way. The current primary focus of these trials is targeting and inhibiting the programmed death 1 (PD-1) axis. Cancer immunotherapy with immune checkpoint modulating drugs seems to be independent of human papilloma virus (HPV) status. Robust predictive markers for patient selection are not yet available.

CONCLUSION

Current data from clinical trials with immune checkpoint modulators are promising. In the coming years, integration of these drugs into clinical routine can be expected. With regard to the public health economic burden and potential adverse events, the identification of predictive markers for patient selection is a major task for future trials.

Intralesional treatment for advanced melanoma: what's on the horizon?

Advances in treatment of melanoma with systemic immunotherapies continue, with promising findings for anti-PD-1 agents combined with ipilimumab. Still, an unmet need persists because of populations ineligible for systemic immunotherapies, incomplete cure/response rates, toxicities and extreme costs. Also, potential for effective use of intralesional therapies remains, especially for local regional disease, but also for benefits of local ablation and adjuvant systemic host tumor-specific responses. Clinical trials of T-VEC, PV-10, CAVATAK and electroporation with plasmid IL-12 have demonstrated favorable, durable responses. Initial experience combining T-VEC, the agent furthest along in testing, with ipilimumab revealed higher complete and overall response rates than with either agent alone. Intralesional therapies may offer a treatment tool in the growing therapeutic armamentarium against this lethal disease.

Economic Burden of Toxicities Associated with Treating Metastatic Melanoma in the United States

BACKGROUND

Little has been reported on the costs of managing the adverse events (AEs) associated with current therapies for patients with regional or distant metastatic melanoma.

OBJECTIVES

To identify treatment-related AEs in patients with metastatic melanoma and to estimate the associated costs of treating these AEs in the United States.

METHODS

A cost-estimation study for AEs associated with treatment of metastatic melanoma was conducted from 2012 to 2013 by identifying grades 3 and 4 AEs through the use of a comprehensive search of drug labels and English-language, published phase 2/3 studies in PubMed, conference abstracts, and the National Comprehensive Cancer Network guidelines. Resource utilization for the management of each type of AE in the outpatient setting was obtained via interviews with 5 melanoma specialists in the United States. Unit costs for an AE associated with melanoma treatment in the outpatient setting were assigned using Medicare reimbursement rates to obtain these costs. Hospitalization and length-of-stay costs were estimated for each associated AE using the large national claims database Optum Clinformatics Data Mart for the period of July 1, 2004, to November 30, 2012.

RESULTS

The most common AEs associated with chemotherapies used for melanoma were neutropenia, vomiting, and anemia. The most common AEs associated with vemurafenib were cutaneous squamous-cell carcinoma or keratoacanthoma, rash, and elevated liver enzymes; the most common AEs associated with dabrafenib were cutaneous squamous-cell carcinoma and pyrexia. Trametinib was most often associated with hypertension and rash. The most common AEs with ipilimumab were immune-related diarrhea or colitis, dyspnea, anemia, vomiting, and, less frequently, hypophysitis. The most common grade 3/4 AE with talimogene laherparepvec was cellulitis. The highest treatment costs for an AE in the outpatient setting were for neutropenia ($2092), headache ($609), and peripheral neuropathy ($539). The highest mean inpatient costs for an AE were for acute myocardial infarction, sepsis, and coma, which ranged from $31,682 to $47,069. Colitis or diarrhea, cutaneous squamous-cell carcinoma, thrombocytopenia, hyponatremia, oliguria or anuria, hypertension, anemia, and elevated liver enzymes were associated with mean costs for hospitalization ranging from $19,122 to $26,861.

CONCLUSION

The costs of managing treatment-related AEs in patients with metastatic melanoma are substantial. Effective treatments with improved safety profiles may help to reduce these costs. Until real-world evidence for the costs associated with treatment toxicity is available in the outpatient and inpatient settings, the costs estimated in this study can help inform decision makers about the cost-effectiveness of managing patients with metastatic melanoma.

Immuno-oncology combinations: raising the tail of the survival curve

There have been exponential gains in immuno-oncology in recent times through the development of immune checkpoint inhibitors. Already approved by the U.S. Food and Drug Administration for advanced melanoma and non-small cell lung cancer, immune checkpoint inhibitors also appear to have significant antitumor activity in multiple other tumor types. An exciting component of immunotherapy is the durability of antitumor responses observed, with some patients achieving disease control for many years. Nevertheless, not all patients benefit, and efforts should thus now focus on improving the efficacy of immunotherapy through the use of combination approaches and predictive biomarkers of response and resistance. There are multiple potential rational combinations using an immunotherapy backbone, including existing treatments such as radiotherapy, chemotherapy or molecularly targeted agents, as well as other immunotherapeutics. The aim of such antitumor strategies will be to raise the tail on the survival curve by increasing the number of long term survivors, while managing any additive or synergistic toxicities that may arise with immunotherapy combinations. Rational trial designs based on a clear understanding of tumor biology and drug pharmacology remain paramount. This article reviews the biology underpinning immuno-oncology, discusses existing and novel immunotherapeutic combinations currently in development, the challenges of predictive biomarkers of response and resistance and the impact of immuno-oncology on early phase clinical trial design.

The role of CTLA-4 and PD-1 in anti-tumor immune response and their potential efficacy against osteosarcoma

Immunotherapy is proved to be a promising therapeutic strategy against human malignancies. Evasion of immune surveillance is considered to be a major factor of malignant progression. Inhibitory receptors, especially CTLA-4 and PD-1, are found to play critical roles in the mediation of anti-tumor immune efficacy. Thus, antibodies targeting these immune checkpoints have emerged as the attractive treatment approaches to those patients with cancer. Osteosarcoma is highly malignant and current treatment remains a challenge, especially for those patients with metastasis. Despite some achievements, the effect of immunotherapy against osteosarcoma is still unsatisfactory. The present review attempts to show the role and mechanism of CTLA-4 and PD-1 in immune response and summarize the recent findings related to the effect of inhibitory receptor antibodies on the immune response against tumors, especially osteosarcoma, and the correlation between PD-1 or/and CTLA-4 expression and outcome of osteosarcoma patients. We further discuss the utilization of the combination therapy against osteosarcoma.

Genomic determinants of cancer immunotherapy

Cancer immunotherapies - including therapeutic vaccines, adoptive cell transfer, oncolytic viruses, and immune checkpoint blockade - yield durable responses in many cancer types, but understanding of predictors of response is incomplete. Genomic characterization of human cancers has already contributed to the success of targeted therapies; in cancer immunotherapy, identification of tumor-specific antigens through whole-exome sequencing may be key to designing individualized, highly immunogenic therapeutic vaccines. Additionally, pre-treatment tumor mutational and gene expression signatures can predict which patients are most likely to benefit from cancer immunotherapy. Continued work in harnessing genomic, transcriptomic, and immunological data from clinical cohorts of immunotherapy-treated patients will bring the promises of precision medicine to immuno-oncology.

Cell division cycle-associated protein 1 as a new melanoma-associated antigen

Immune checkpoint inhibitors have increased the median survival of melanoma patients. To improve their effects, antigen-specific therapies utilizing melanoma-associated antigens should be developed. Cell division cycle-associated protein 1 (CDCA1), which has a specific function at the kinetochores for stabilizing microtubule attachment, is overexpressed in various cancers. CDCA1, which is a member of cancer-testis antigens, does not show detectable expression levels in normal tissues. Quantitative reverse transcription polymerase chain reaction and immunoblotting analyses revealed that CDCA1 was expressed in all of the tested melanoma cell lines, 74% of primary melanomas, 64% of metastatic melanomas and 25% of nevi. An immunohistochemical analysis and a Cox proportional hazards model showed that CDCA1 could be a prognostic marker in malignant melanoma (MM) patients. CDCA1-specific siRNA inhibited the cell proliferation of SKMEL2 and WM115 cells, but did not reduce the migration or invasion activity. These results suggest that CDCA1 may be a new therapeutic target of melanoma.

Current status and perspectives in translational biomarker research for PD-1/PD-L1 immune checkpoint blockade therapy

Modulating immune inhibitory pathways has been a major recent breakthrough in cancer treatment. Checkpoint blockade antibodies targeting cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programed cell-death protein 1 (PD-1) have demonstrated acceptable toxicity, promising clinical responses, durable disease control, and improved survival in some patients with advanced melanoma, non-small cell lung cancer (NSCLC), and other tumor types. About 20 % of advanced NSCLC patients and 30 % of advanced melanoma patients experience tumor responses from checkpoint blockade monotherapy, with better clinical responses seen with the combination of anti-PD-1 and anti-CTLA-4 antibodies. Given the power of these new therapies, it is important to understand the complex and dynamic nature of host immune responses and the regulation of additional molecules in the tumor microenvironment and normal organs in response to the checkpoint blockade therapies. In this era of precision oncology, there remains a largely unmet need to identify the patients who are most likely to benefit from immunotherapy, to optimize the monitoring assays for tumor-specific immune responses, to develop strategies to improve clinical efficacy, and to identify biomarkers so that immune-related adverse events can be avoided. At this time, PD-L1 immunohistochemistry (IHC) staining using 22C3 antibody is the only FDA-approved companion diagnostic for patients with NSCLC-treated pembrolizumab, but more are expected to come to market. We here summarize the current knowledge, clinical efficacy, potential immune biomarkers, and associated assays for immune checkpoint blockade therapies in advanced solid tumors.

Quantitative CD3 PET Imaging Predicts Tumor Growth Response to Anti-CTLA-4 Therapy

Immune checkpoint inhibitors have made rapid advances, resulting in multiple Food and Drug Administration-approved therapeutics that have markedly improved survival. However, these benefits are limited to a minority subpopulation that achieves a response. Predicting which patients are most likely to benefit would be valuable for individual therapy optimization. T-cell markers such as CD3-by examining active recruitment of the T cells responsible for cancer-cell death-represent a more direct approach to monitoring tumor immune response than pretreatment biopsy or genetic screening. This approach could be especially effective as numerous different therapeutic strategies emerge, decreasing the need for drug-specific biomarkers and instead focusing on T-cell infiltration, which has been previously correlated with treatment response.

METHODS

A CD3 PET imaging agent targeting T cells was synthesized to test the role of such imaging as a predictive marker. The ⁸⁹Zr-p-isothiocyanatobenzyl-deferoxamine-CD3 PET probe was assessed in a murine tumor xenograft model of anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) immunotherapy of colon cancer.

RESULTS

Imaging on day 14 revealed 2 distinct groups of mice stratified by PET signal intensity. Although there was no significant difference in tumor volume on the day of imaging, in the high-uptake group subsequent measurements revealed significantly smaller tumors than in either the low-uptake group or the untreated controls. In contrast, there was no significant difference in the size of tumors between the low-uptake and untreated control mice.

CONCLUSION

These findings indicate that high CD3 PET uptake in the anti-CTLA-4-treated mice correlated with subsequent reduced tumor volume and was a predictive biomarker of response.

Checkpoint Blockade - a New Treatment Paradigm in Renal Cell Carcinoma

Nivolumab is the first checkpoint inhibitor for the treatment of renal cell carcinoma (RCC), which is in line for approval in Europe. Despite its novelty in the treatment algorithm of RCC, it offers a whole new strategy of therapy management with safe applicability. The aim of this work was to review current data on checkpoint inhibitors in RCC and discuss future perspectives for this novel approach in RCC. A selective literature search was performed in the Pubmed database: Nivolumab is a first-in-class agent for the treatment of RCC, and its European label is anticipated for 2016. Contrary to many other agents, nivolumab was able to show a benefit in overall survival and health-related quality of life when compared to everolimus. Current trials focus on optimizing and expanding its use to metastatic RCC. In conclusion, nivolumab has already acquired a role in the treatment algorithm of RCC. However, which patient population derives the most benefit as well its optimal use in the treatment algorithm remain to be determined. A number of ongoing trials will provide novel insights and might help to untangle this novel network of therapy management for immunotherapies.

[ESMO ECCO 2015: The highlights of immunotherapy and targeted therapies]

The ESMO/ECC congress (European Society for Medical Oncology/European Cancer Congress) took place in Vienna, Austria, September 25-29. The main topic of the conference was immunotherapies especially in advanced kidney cancer with nivolumab in phase III and in metastatic lung cancer with atezolizumab in phase II. Targeted therapies were also highlighted with cabozantinib proposed in advanced renal cancer or everolimus in differenciated neuroendocrine tumors grade 1 or 2. Furthermore the current challenges remain unchanged: improving patients' care through better selection and finding biomarkers using simple samples (blood or urine). Also early phases and personalized medicine found their place in the different presentations and were highlighted largely bringing new approaches in the treatment of metastatic patients.

Randomized, Prospective Evaluation Comparing Intensity of Lymphodepletion Before Adoptive Transfer of Tumor-Infiltrating Lymphocytes for Patients With Metastatic Melanoma

PURPOSE

Adoptive cell transfer, the infusion of large numbers of activated autologous lymphocytes, can mediate objective tumor regression in a majority of patients with metastatic melanoma (52 of 93; 56%). Addition and intensification of total body irradiation (TBI) to the preparative lymphodepleting chemotherapy regimen in sequential trials improved objective partial and complete response (CR) rates. Here, we evaluated the importance of adding TBI to the adoptive transfer of tumor-infiltrating lymphocytes (TIL) in a randomized fashion.

PATIENTS AND METHODS

A total of 101 patients with metastatic melanoma, including 76 patients with M1c disease, were randomly assigned to receive nonmyeloablative chemotherapy with or without 1,200 cGy TBI before transfer of tumor-infiltrating lymphcytes. Primary end points were CR rate (as defined by Response Evaluation Criteria in Solid Tumors v1.0) and overall survival (OS). Clinical and laboratory data were analyzed for correlates of response.

RESULTS

CR rates were 24% in both groups (12 of 50 v 12 of 51), and OS was also similar (median OS, 38.2 v 36.6 months; hazard ratio, 1.11; 95% CI, 0.65 to 1.91; P = .71). Thrombotic microangiopathy was an adverse event unique to the TBI arm and occurred in 13 of 48 treated patients. With a median potential follow-up of 40.9 months, only one of 24 patients who achieved a CR recurred.

CONCLUSION

Adoptive cell transfer can mediate durable complete regressions in 24% of patients with metastatic melanoma, with median survival > 3 years. Results were similar using chemotherapy preparative regimens with or without addition of TBI.

Sarcomatoid lung carcinomas show high levels of programmed death ligand-1 (PD-L1) and strong immune-cell infiltration by TCD3 cells and macrophages

OBJECTIVES

Pulmonary sarcomatoid carcinomas (SC) are rare tumors, associated with worse prognosis and resistant to platinum-based regimens. Therapies targeting the PD-1/PD-L1 pathway are an emerging treatment for lung cancer. By characterizing intra-tumoral immune infiltration and evaluating PD-L1 expression, it could be possible to predict the efficacy of these new treatments.

MATERIALS AND METHODS

From 1997 to 2013, data from all patients with SC who underwent lung resection was collected. Tumor-immune infiltration and PD-L1 expression were studied by immunochemistry tests, analyzing CD3 (clone SP7), CD4 (clone 1F6), CD8 (clone C8/144b), CD20 (clone L26), CD163 (clone 10D6), MPO (clone 59A5), and PD-L1 (clone 5H1). Results were compared to those of 54 NSCLC.

RESULTS

In total, 75 SC were included. Forty (53%) SC expressed PD-L1 vs 11 NSCLC (20%) (p<0.0001). CD3+ tumor-infiltrating lymphocytes and CD163+ tumor-associated macrophages were more important in SC than in NSCLC (median 23% [17-30] of tumoral surface vs 17% [7-27], p=0.011 and 23% [17-30] vs 20% [13-23], p=0.002, respectively). In SC, the presence of Kirsten Ras (KRAS) mutations, blood vessel invasion, and TTF1+ positivity were associated with PDL1 expression. On multivariate analysis, only CD163+ macrophages and blood-vessel invasion were associated with tumoral PD-L1 expression. High levels of tumor-infiltrating lymphocytes (CD3+ or CD4+ and not CD8+) constituted a factor of good prognosis on survival. Interestingly, PD-L1 expression distinguishes subpopulations within tumor-infiltrating lymphocytes (CD3+ or CD4+) with different prognosis

CONCLUSIONS

PD-L1 expression was higher in SC than in NSCLC as well as immune-cell infiltration by TCD3 cells and macrophages. This suggests that targeting the PD-1/PD-L1 pathway could represent a new potential therapy.

Targeted Therapy and Checkpoint Immunotherapy Combinations for the Treatment of Cancer

Many advances in the treatment of cancer have been driven by the development of targeted therapies that inhibit oncogenic signaling pathways and tumor-associated angiogenesis, as well as by the recent development of therapies that activate a patient's immune system to unleash antitumor immunity. Some targeted therapies can have effects on host immune responses, in addition to their effects on tumor biology. These immune-modulating effects, such as increasing tumor antigenicity or promoting intratumoral T cell infiltration, provide a rationale for combining these targeted therapies with immunotherapies. Here, we discuss the immune-modulating effects of targeted therapies against the MAPK and VEGF signaling pathways, and how they may synergize with immunomodulatory antibodies that target PD1/PDL1 and CTLA4. We critically examine the rationale in support of these combinations in light of the current understanding of the underlying mechanisms of action of these therapies. We also discuss the available preclinical and clinical data for these combination approaches and their implications regarding mechanisms of action. Insights from these studies provide a framework for considering additional combinations of targeted therapies and immunotherapies for the treatment of cancer.

Phase I study to evaluate toxicity and feasibility of intratumoral injection of α-gal glycolipids in patients with advanced melanoma

Effective uptake of tumor cell-derived antigens by antigen-presenting cells is achieved pre-clinically by in situ labeling of tumor with α-gal glycolipids that bind the naturally occurring anti-Gal antibody. We evaluated toxicity and feasibility of intratumoral injections of α-gal glycolipids as an autologous tumor antigen-targeted immunotherapy in melanoma patients (pts). Pts with unresectable metastatic melanoma, at least one cutaneous, subcutaneous, or palpable lymph node metastasis, and serum anti-Gal titer ≥1:50 were eligible for two intratumoral α-gal glycolipid injections given 4 weeks apart (cohort I: 0.1 mg/injection; cohort II: 1.0 mg/injection; cohort III: 10 mg/injection). Monitoring included blood for clinical, autoimmune, and immunological analyses and core tumor biopsies. Treatment outcome was determined 8 weeks after the first α-gal glycolipid injection. Nine pts received two intratumoral injections of α-gal glycolipids (3 pts/cohort). Injection-site toxicity was mild, and no systemic toxicity or autoimmunity could be attributed to the therapy. Two pts had stable disease by RECIST lasting 8 and 7 months. Tumor nodule biopsies revealed minimal to no change in inflammatory infiltrate between pre- and post-treatment biopsies except for 1 pt (cohort III) with a post-treatment inflammatory infiltrate. Two and four weeks post-injection, treated nodules in 5 of 9 pts exhibited tumor cell necrosis without neutrophilic or lymphocytic inflammatory response. Non-treated tumor nodules in 2 of 4 evaluable pts also showed necrosis. Repeated intratumoral injections of α-gal glycolipids are well tolerated, and tumor necrosis was seen in some tumor nodule biopsies after tumor injection with α-gal glycolipids.

Immune escape to PD-L1/PD-1 blockade: seven steps to success (or failure)

The emergence of programmed death-ligand 1 (PD-L1)/programmed death-1 (PD-1)-targeted therapy has demonstrated the importance of the PD-L1 : PD-1 interaction in inhibiting anticancer T-cell immunity in multiple human cancers, generating durable responses and extended overall survival. However, not all patients treated with PD-L1/PD-1-targeted therapy experience tumor shrinkage, durable responses, or prolonged survival. To extend such benefits to more cancer patients, it is necessary to understand why some patients experience primary or secondary immune escape, in which the immune response is incapable of eradicating all cancer cells. Understanding immune escape from PD-L1/PD-1-targeted therapy will be important to the development of rational immune-combination therapy and predictive diagnostics and to the identification of novel immune targets. Factors that likely relate to immune escape include the lack of strong cancer antigens or epitopes recognized by T cells, minimal activation of cancer-specific T cells, poor infiltration of T cells into tumors, downregulation of the major histocompatibility complex on cancer cells, and immunosuppressive factors and cells in the tumor microenvironment. Precisely identifying and understanding these mechanisms of immune escape in individual cancer patients will allow for personalized cancer immunotherapy, in which monotherapy and combination immunotherapy are chosen based on the presence of specific immune biology. This approach may enable treatment with immunotherapy without inducing immune escape, resulting in a larger proportion of patients obtaining clinical benefit.

Molecular Pathways: Targeting B7-H3 (CD276) for Human Cancer Immunotherapy

B7-H3 (CD276) is an important immune checkpoint member of the B7 and CD28 families. Induced on antigen-presenting cells, B7-H3 plays an important role in the inhibition of T-cell function. Importantly, B7-H3 is highly overexpressed on a wide range of human solid cancers and often correlates with both negative prognosis and poor clinical outcome in patients. Challenges remain to identify the receptor(s) of B7-H3 and thus better elucidate the role of the B7-H3 pathway in immune responses and tumor evasion. With a preferential expression on tumor cells, B7-H3 is an attractive target for cancer immunotherapy. Based on the clinical success of inhibitory immune checkpoint blockade (CTLA-4, PD-1, and PD-L1), mAbs against B7-H3 appear to be a promising therapeutic strategy worthy of development. An unconventional mAb against B7-H3 with antibody-dependent cell-mediated cytotoxicity is currently being evaluated in a phase I clinical trial and has shown encouraging preliminary results. Additional therapeutic approaches in targeting B7-H3, such as blocking mAbs, bispecific mAbs, chimeric antigen receptor T cells, small-molecule inhibitors, and combination therapies, should be evaluated, as these technologies have already shown positive results in various cancer settings. A better understanding of the B7-H3 pathway in humans will surely help to further optimize associated cancer immunotherapies. Clin Cancer Res; 22(14); 3425-31. ©2016 AACR.

Immunosuppressive activities of adenosine in cancer

Multiple immunosuppressive mechanisms impede anti-tumor immunity. Among them, the accumulation of extracellular adenosine is a potent and widespread strategy exploited by tumors to escape immunosurveillance through the activation of purinergic receptors. In the immune system, engagement of A2a and A2b adenosine receptors is a critical regulatory mechanism that protects tissues against excessive immune reactions. In tumors, this pathway is hijacked and hinders anti-tumor immunity, promoting cancer progression. Different groups have highlighted the therapeutic potential of blocking CD73-dependent adenosine-mediated immunosuppression to reinstate anti-tumor immunity. Phase clinical trials evaluating anti-CD73 antibodies and A2a receptor antagonists in cancer patients are currently ongoing. We here review the recent literature on the immunosuppressive effects of extracellular adenosine and discuss the development of adenosine inhibitors.

Nivolumab: A Review in Advanced Melanoma

An improved understanding of cancer genetics and immune regulatory pathways, including those associated with evasion of immune surveillance by tumours, has culminated in the development of several targeted therapies. One such strategy that acts to negate evasion of immune surveillance by tumours is inhibition of the programmed cell death receptor-1 (PD-1) checkpoint pathway. Intravenous nivolumab (Opdivo(®)), a PD-1 checkpoint inhibitor, is approved or in pre-registration in various countries for use in adult patients with advanced melanoma, with the recommended monotherapy dosage being a 60-min infusion of 3 mg/kg once every 2 weeks. In well-designed multinational trials, as monotherapy or in combination with ipilimumab (a cytotoxic T-lymphocyte antigen 4 checkpoint inhibitor), nivolumab significantly improved clinical outcomes and had a manageable tolerability profile in adult patients with advanced melanoma with or without BRAF mutations. Nivolumab monotherapy was associated with a higher objective response rate (ORR) than chemotherapy in treatment-experienced patients and a higher ORR and prolonged progression-free survival (PFS) and overall survival than dacarbazine in treatment-naive patients. In combination with ipilimumab, nivolumab was associated with an improved ORR and prolonged PFS compared with ipilimumab monotherapy in treatment-naive patients. In addition, nivolumab monotherapy significantly prolonged PFS and improved ORRs compared with ipilimumab monotherapy. The optimal combination regimen for immune checkpoint inhibitors remains to be fully elucidated, with various combination regimens and different sequences of individual immunotherapies currently being investigated in ongoing clinical trials. Given the significant improvements in outcomes associated with nivolumab in clinical trials, nivolumab monotherapy or combination therapy is a valuable first-line or subsequent treatment option for adult patients with unresectable or metastatic melanoma, irrespective of BRAF mutation status.

Burden of Nonsynonymous Mutations among TCGA Cancers and Candidate Immune Checkpoint Inhibitor Responses

Immune checkpoint inhibitor treatment represents a promising approach toward treating cancer and has been shown to be effective in a subset of melanoma, non-small cell lung cancer (NSCLC), and kidney cancers. Recent studies have suggested that the number of nonsynonymous mutations (NsM) can be used to select melanoma and NSCLC patients most likely to benefit from checkpoint inhibitor treatment. It is hypothesized that a higher burden of NsM generates novel epitopes and gene products, detected by the immune system as foreign. We conducted an assessment of NsM across 7,757 tumor samples drawn from 26 cancers sequenced in the Cancer Genome Atlas (TCGA) Project to estimate the subset of cancers (both types and fractions thereof) that fit the profile suggested for melanoma and NSCLC. An additional independent set of 613 tumors drawn from 5 cancers were analyzed for replication. An analysis of the receiver operating characteristic curves of published data on checkpoint inhibitor response in melanoma and NSCLC data estimates a cutoff of 192 NsM with 74% sensitivity and 59.3% specificity to discriminate potential clinical benefit. Across the 7,757 samples of TCGA, 16.2% displayed an NsM count that exceeded the threshold of 192. It is notable that more than 30% of bladder, colon, gastric, and endometrial cancers have NsM counts above 192, which was also confirmed in melanoma and NSCLC. Our data could inform the prioritization of tumor types (and subtypes) for possible clinical trials to investigate further indications for effective use of immune checkpoint inhibitors, particularly in adult cancers. Cancer Res; 76(13); 3767-72. ©2016 AACR.

PSGL-1 Is an Immune Checkpoint Regulator that Promotes T Cell Exhaustion

Chronic viruses and cancers thwart immune responses in humans by inducing T cell dysfunction. Using a murine chronic virus that models human infections, we investigated the function of the adhesion molecule, P-selectin glycoprotein ligand-1 (PSGL-1), that is upregulated on responding T cells. PSGL-1-deficient mice cleared the virus due to increased intrinsic survival of multifunctional effector T cells that had downregulated PD-1 as well as other inhibitory receptors. Notably, this response resulted in CD4(+)-T-cell-dependent immunopathology. Mechanistically, PSGL-1 ligation on exhausted CD8(+) T cells inhibited T cell receptor (TCR) and interleukin-2 (IL-2) signaling and upregulated PD-1, leading to diminished survival with TCR stimulation. In models of melanoma cancer in which T cell dysfunction occurs, PSGL-1 deficiency led to PD-1 downregulation, improved T cell responses, and tumor control. Thus, PSGL-1 plays a fundamental role in balancing viral control and immunopathology and also functions to regulate T cell responses in the tumor microenvironment.

Triple-negative breast cancer: challenges and opportunities of a heterogeneous disease

Chemotherapy is the primary established systemic treatment for patients with triple-negative breast cancer (TNBC) in both the early and advanced-stages of the disease. The lack of targeted therapies and the poor prognosis of patients with TNBC have fostered a major effort to discover actionable molecular targets to treat patients with these tumours. Massively parallel sequencing and other 'omics' technologies have revealed an unexpected level of heterogeneity of TNBCs and have led to the identification of potentially actionable molecular features in some TNBCs, such as germline BRCA1/2 mutations or 'BRCAness', the presence of the androgen receptor, and several rare genomic alterations. Whether these alterations are molecular 'drivers', however, has not been clearly established. A subgroup of TNBCs shows a high degree of tumour-infiltrating lymphocytes that also correlates with a lower risk of disease relapse and a higher likelihood of benefit from chemotherapy. Proof-of-principle studies with immune-checkpoint inhibitors in advanced-stage TNBC have yielded promising results, indicating the potential benefit of immunotherapy for patients with TNBC. In this Review, we discuss the most relevant molecular findings in TNBC from the past decade and the most promising therapeutic opportunities derived from these data.

PD-1/CTLA-4 Blockade Inhibits Epstein-Barr Virus-Induced Lymphoma Growth in a Cord Blood Humanized-Mouse Model

Epstein-Barr virus (EBV) infection causes B cell lymphomas in humanized mouse models and contributes to a variety of different types of human lymphomas. T cells directed against viral antigens play a critical role in controlling EBV infection, and EBV-positive lymphomas are particularly common in immunocompromised hosts. We previously showed that EBV induces B cell lymphomas with high frequency in a cord blood-humanized mouse model in which EBV-infected human cord blood is injected intraperitoneally into NOD/LtSz-scid/IL2Rγ^null (NSG) mice. Since our former studies showed that it is possible for T cells to control the tumors in another NSG mouse model engrafted with both human fetal CD34+ cells and human thymus and liver, here we investigated whether monoclonal antibodies that block the T cell inhibitory receptors, PD-1 and CTLA-4, enhance the ability of cord blood T cells to control the outgrowth of EBV-induced lymphomas in the cord-blood humanized mouse model. We demonstrate that EBV-infected lymphoma cells in this model express both the PD-L1 and PD-L2 inhibitory ligands for the PD-1 receptor, and that T cells express the PD-1 and CTLA-4 receptors. Furthermore, we show that the combination of CTLA-4 and PD-1 blockade strikingly reduces the size of lymphomas induced by a lytic EBV strain (M81) in this model, and that this anti-tumor effect requires T cells. PD-1/CTLA-4 blockade markedly increases EBV-specific T cell responses, and is associated with enhanced tumor infiltration by CD4+ and CD8+ T cells. In addition, PD-1/CTLA-4 blockade decreases the number of both latently, and lytically, EBV-infected B cells. These results indicate that PD-1/CTLA-4 blockade enhances the ability of cord blood T cells to control outgrowth of EBV-induced lymphomas, and suggest that PD-1/CTLA-4 blockade might be useful for treating certain EBV-induced diseases in humans.

EBV is a human herpesvirus that remains in the host for life, but is normally well controlled by the host immune response. Nevertheless, EBV causes lymphomas in certain individuals, particularly when T cell function is impaired. Antibodies against two different inhibitory receptors on T cells, PD-1 and CTLA-4, have been recently shown to improve T cell cytotoxic function against a subset of non-virally associated tumors. Here we have used an EBV-infected cord blood-humanized mouse model to show that EBV-infected lymphomas express both the PD-L1 and PD-L2 inhibitory ligands for PD-1. Importantly, we find that the combination of PD-1 and CTLA-4 blockade decreases the growth of EBV-induced lymphomas in this model, and demonstrate that this anti-tumor effect requires T cells and enhances their responses to EBV. Our results suggest that PD-1/CTLA-4 blockade might be useful for treating certain EBV-associated diseases in humans.

Adoptive immunotherapy against ovarian cancer

The standard front-line therapy for epithelial ovarian cancer (EOC) is combination of debulking surgery and platinum-based chemotherapy. Nevertheless, the majority of patients experience disease recurrence. Although extensive efforts to find new therapeutic options, cancer cells invariably develop drug resistance and disease progression. New therapeutic strategies are needed to improve prognosis of patients with advanced EOC.

Recently, several preclinical and clinical studies investigated feasibility and activity of adoptive immunotherapy in EOC. Our aim is to highlight prospective of adoptive immunotherapy in EOC, focusing on HLA-restricted Tumor Infiltrating Lymphocytes (TILs), and MHC-independent immune effectors such as natural killer (NK), and cytokine-induced killer (CIK). Adoptive cell therapy (ACT) has shown activity in several pre-clinical models. Available preclinical and clinical data suggest that adoptive cell therapy may provide the best benefit in settings of low tumor burden, minimal residual disease, or maintenance therapy. Further studies are needed to better define the optimal clinical setting.

Baseline Biomarkers for Outcome of Melanoma Patients Treated with Pembrolizumab

PURPOSE

Biomarkers for outcome after immune-checkpoint blockade are strongly needed as these may influence individual treatment selection or sequence. We aimed to identify baseline factors associated with overall survival (OS) after pembrolizumab treatment in melanoma patients.

EXPERIMENTAL DESIGN

Serum lactate dehydrogenase (LDH), routine blood count parameters, and clinical characteristics were investigated in 616 patients. Endpoints were OS and best overall response following pembrolizumab treatment. Kaplan-Meier analysis and Cox regression were applied for survival analysis.

RESULTS

Relative eosinophil count (REC) ≥1.5%, relative lymphocyte count (RLC) ≥17.5%, ≤2.5-fold elevation of LDH, and the absence of metastasis other than soft-tissue/lung were associated with favorable OS in the discovery (n = 177) and the confirmation (n = 182) cohort and had independent positive impact (all P < 0.001). Their independent role was subsequently confirmed in the validation cohort (n = 257; all P < 0.01). The number of favorable factors was strongly associated with prognosis. One-year OS probabilities of 83.9% versus 14.7% and response rates of 58.3% versus 3.3% were observed in patients with four of four compared to those with none of four favorable baseline factors present, respectively.

CONCLUSIONS

High REC and RLC, low LDH, and absence of metastasis other than soft-tissue/lung are independent baseline characteristics associated with favorable OS of patients with melanoma treated with pembrolizumab. Presence of four favorable factors in combination identifies a subgroup with excellent prognosis. In contrast, patients with no favorable factors present have a poor prognosis, despite pembrolizumab, and additional treatment advances are still needed. A potential predictive impact needs to be further investigated. Clin Cancer Res; 22(22); 5487-96. ©2016 AACR.

[Systemic treatment of inoperable metastasized malignant melanoma]

BACKGROUND

The medical therapy of inoperable malignant melanoma has changed dramatically over the last few years.

OBJECTIVES

The purpose of this article is to summarize the current state of systemic medical treatment of malignant melanoma.

MATERIALS AND METHODS

Clinical studies and guidelines in the therapy of malignant melanoma are reviewed.

RESULTS

Medical therapy of inoperable melanoma changed due to developments in immunotherapies (checkpoint inhibitors) and molecular-targeted therapies (BRAF and MEK inhibitors). Checkpoint inhibitors are antibodies administered as infusions every 2-3 weeks, blocking the checkpoints PD-1 or CTLA-4, thus, preventing downregulation of the immune system. BRAF and MEK inhibitors are small molecules, they are given orally and block a certain signaling pathway in tumor cells. The activation of this pathway has to be demonstrated by molecular analysis of tumor tissue first. This strategy is currently registered for 40-50 % of melanomas harboring a BRAF V600 mutation, while the combination of a BRAF plus MEK inhibitor has been proven more efficient than a BRAF inhibitor alone.

DISCUSSION

A fascinating development has started in the melanoma field due to immunotherapeutic and molecular-targeted treatment strategies. The continuation of this development needs further clinical and translational studies. This includes particular clinical studies with the new substances in the adjuvant situation, and sequences and combinations in the metastatic setting. Translational studies are needed to develop biomarkers for response and side effects.

Increases in Absolute Lymphocytes and Circulating CD4+ and CD8+ T Cells Are Associated with Positive Clinical Outcome of Melanoma Patients Treated with Ipilimumab

PURPOSE

To investigate changes of peripheral blood biomarkers and their impact on clinical outcome following treatment with ipilimumab in advanced melanoma patients.

EXPERIMENTAL DESIGN

Changes in blood counts and the frequency of circulating immune cell populations analyzed by flow cytometry were investigated in 82 patients to compare baseline values with different time-points after starting ipilimumab. Endpoints were overall survival (OS) and best clinical response. Statistical calculations were done by Wilcoxon-matched pairs tests, Fisher exact test, Kaplan-Meier analysis, and Cox regression analysis.

RESULTS

Increases in absolute lymphocyte counts (ALC) 2 to 8 weeks (P = 0.003) and in percentages of CD4⁺ and CD8⁺ T cells 8 to 14 weeks (P = 0.001 and P = 0.02) after the first dose of ipilimumab were correlated with improved survival. These associations did not meet significance criteria, when conservatively adjusted for multiple testing, but were additionally correlated with clinical responses (all P < 0.05). However, validation is required. Increases in all three factors were observed in 36% of patients, who had a favorable outcome and survival probabilities of 93.3% and 63.8% at 12 and 24 months, respectively. A partial or complete response was observed in 71% of these patients compared with only 8% in patients with decreases in ≥1 of the 3 factors, respectively. Changes of regulatory T cells or myeloid-derived suppressor cells were not associated with OS.

CONCLUSIONS

Increases of ALC observed 2 to 8 weeks after initiation of ipilimumab and delayed increases in CD4⁺ and CD8⁺ T cells reflect changes associated with positive outcome. These changes represent surrogate marker candidates and warrant further validation. Clin Cancer Res; 22(19); 4848-58. ©2016 AACR.

Concomitant targeting of programmed death-1 (PD-1) and CD137 improves the efficacy of radiotherapy in a mouse model of human BRAFV600-mutant melanoma

T cell checkpoint blockade with antibodies targeting programmed cell death (ligand)-1 (PD-1/PD-L1) and/or cytotoxic T lymphocyte-antigen 4 (CTLA-4) has improved therapy outcome in melanoma patients. However, a considerable proportion of patients does not benefit even from combined α-CTLA-4 and α-PD-1 therapy. We therefore examined to which extent T cell (co)stimulation and/or stereotactic body radiation therapy (SBRT) could further enhance the therapeutic efficacy of T cell checkpoint blockade in a genetically engineered mouse melanoma model that is driven by PTEN-deficiency, and BRAFV600 mutation, as in human, but lacks the sporadic UV-induced mutations. Tumor-bearing mice were treated with different combinations of immunomodulatory antibodies (α-CTLA-4, α-PD-1, α-CD137) or interleukin-2 (IL-2) alone or in combination with SBRT. None of our immunotherapeutic approaches (alone or in combination) had any anti-tumor efficacy, while SBRT alone delayed melanoma outgrowth. However, α-CD137 combined with α-PD-1 antibodies significantly enhanced the anti-tumor effect of SBRT, while the anti-tumor effect of SBRT was not enhanced by interleukin-2, or the combination of α-CTLA-4 and α-PD-1. We conclude that α-CD137 and α-PD-1 antibodies were most effective in enhancing SBRT-induced tumor growth delay in this mouse melanoma model, outperforming the ability of IL-2, or the combination of α-CTLA-4 and α-PD-1 to synergize with SBRT. Given the high mutational load and increased immunogenicity of human melanoma with the same genotype, our findings encourage testing α-CD137 and α-PD-1 alone or in combination with SBRT clinically, particularly in patients refractory to α-CTLA-4 and/or α-PD-1 therapy.

Roles of regulatory T cells in cancer immunity

CD4(+) regulatory T cells (Tregs) expressing the transcription factor FoxP3 are highly immune suppressive and play central roles in the maintenance of self-tolerance and immune homeostasis, yet in malignant tumors they promote tumor progression by suppressing effective antitumor immunity. Indeed, higher infiltration by Tregs is observed in tumor tissues, and their depletion augments antitumor immune responses in animal models. Additionally, increased numbers of Tregs and, in particular, decreased ratios of CD8(+) T cells to Tregs among tumor-infiltrating lymphocytes are correlated with poor prognosis in various types of human cancers. The recent success of cancer immunotherapy represented by immune checkpoint blockade has provided a new insight in cancer treatment, yet more than half of the treated patients did not experience clinical benefits. Identifying biomarkers that predict clinical responses and developing novel immunotherapies are therefore urgently required. Cancer patients whose tumors contain a large number of neoantigens stemming from gene mutations, which have not been previously recognized by the immune system, provoke strong antitumor T-cell responses associated with clinical responses following immune checkpoint blockade, depending on the resistance to Treg-mediated suppression. Thus, integration of a strategy restricting Treg-mediated immune suppression may expand the therapeutic spectrum of cancer immunotherapy towards patients with a lower number of neoantigens. In this review, we address the current understanding of Treg-mediated immune suppressive mechanisms in cancer, the involvement of Tregs in cancer immunotherapy, and strategies for effective and tolerable Treg-targeted therapy.

Immune activation and response to pembrolizumab in POLE-mutant endometrial cancer

Antibodies that target the immune checkpoint receptor programmed cell death protein 1 (PD-1) have resulted in prolonged and beneficial responses toward a variety of human cancers. However, anti-PD-1 therapy in some patients provides no benefit and/or results in adverse side effects. The factors that determine whether patients will be drug sensitive or resistant are not fully understood; therefore, genomic assessment of exceptional responders can provide important insight into patient response. Here, we identified a patient with endometrial cancer who had an exceptional response to the anti-PD-1 antibody pembrolizumab. Clinical grade targeted genomic profiling of a pretreatment tumor sample from this individual identified a mutation in DNA polymerase epsilon (POLE) that associated with an ultramutator phenotype. Analysis of The Cancer Genome Atlas (TCGA) revealed that the presence of POLE mutation associates with high mutational burden and elevated expression of several immune checkpoint genes. Together, these data suggest that cancers harboring POLE mutations are good candidates for immune checkpoint inhibitor therapy.

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.

Cancer immunotherapy: the beginning of the end of cancer?

These are exciting times for cancer immunotherapy. After many years of disappointing results, the tide has finally changed and immunotherapy has become a clinically validated treatment for many cancers. Immunotherapeutic strategies include cancer vaccines, oncolytic viruses, adoptive transfer of ex vivo activated T and natural killer cells, and administration of antibodies or recombinant proteins that either costimulate cells or block the so-called immune checkpoint pathways. The recent success of several immunotherapeutic regimes, such as monoclonal antibody blocking of cytotoxic T lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD1), has boosted the development of this treatment modality, with the consequence that new therapeutic targets and schemes which combine various immunological agents are now being described at a breathtaking pace. In this review, we outline some of the main strategies in cancer immunotherapy (cancer vaccines, adoptive cellular immunotherapy, immune checkpoint blockade, and oncolytic viruses) and discuss the progress in the synergistic design of immune-targeting combination therapies.