Cancer immunotherapies that target the programmed cell death 1 (PD-1):programmed death-ligand 1 (PD-L1) immune checkpoint pathway have ushered in the modern oncology era. Drugs that block PD-1 or ...PD-L1 facilitate endogenous antitumor immunity and, because of their broad activity spectrum, have been regarded as a common denominator for cancer therapy. Nevertheless, many advanced tumors demonstrate de novo or acquired treatment resistance, and ongoing research efforts are focused on improving patient outcomes. Using anti-PD-1 or anti-PD-L1 treatment against earlier stages of cancer is hypothesized to be one such solution. This Review focuses on the development of neoadjuvant (presurgical) immunotherapy in the era of PD-1 pathway blockade, highlighting particular considerations for biological mechanisms, clinical trial design, and pathologic response assessments. Findings from neoadjuvant immunotherapy studies may reveal pathways, mechanisms, and molecules that can be cotargeted in new treatment combinations to increase anti-PD-1 and anti-PD-L1 efficacy.
Drug development in oncology has traditionally focused on therapies that directly target cancer cells-surgery, radiation therapy, chemotherapy, and kinase inhibitors. However, for more than a century ...it has also been recognized that the immune system interacts with cancer. The immune surveillance hypothesis, proposed in the 1950s, posited that the immune system could recognize and reject cancer cells as being foreign. in the same way that it reacts against microbial agents and transplanted organs. Here, Topalian talks about the interactions between cancer and the immune system that a quantum leap in immuno-oncology occurred.
The immune system recognizes and is poised to eliminate cancer but is held in check by inhibitory receptors and ligands. These immune checkpoint pathways, which normally maintain self-tolerance and ...limit collateral tissue damage during anti-microbial immune responses, can be co-opted by cancer to evade immune destruction. Drugs interrupting immune checkpoints, such as anti-CTLA-4, anti-PD-1, anti-PD-L1, and others in early development, can unleash anti-tumor immunity and mediate durable cancer regressions. The complex biology of immune checkpoint pathways still contains many mysteries, and the full activity spectrum of checkpoint-blocking drugs, used alone or in combination, is currently the subject of intense study.
Highlights ► PD-1/B7-H1 are pivotal in maintaining an immunosuppressive tumor microenvironment. ► PD-1 and CTLA-4 play distinct roles in regulating immunity. ► B7-H1 upregulation on tumor cells ...likely reflects ‘adaptive resistance’. ► PD-1 blockade is active against NSCLC, thought to be a ‘non-immunogenic’ tumor. ► Monotherapies blocking PD-1 may be more effective in combinatorial regimens.
Cancer Immunotherapy Comes of Age TOPALIAN, Suzanne L; WEINER, George J; PARDOLL, Drew M
Journal of clinical oncology,
12/2011, Letnik:
29, Številka:
36
Journal Article
Recenzirano
Odprti dostop
Cancer immunotherapy comprises a variety of treatment approaches, incorporating the tremendous specificity of the adaptive immune system (T cells and antibodies) as well as the diverse and potent ...cytotoxic weaponry of both adaptive and innate immunity. Immunotherapy strategies include antitumor monoclonal antibodies, cancer vaccines, adoptive transfer of ex vivo activated T and natural killer cells, and administration of antibodies or recombinant proteins that either costimulate immune cells or block immune inhibitory pathways (so-called immune checkpoints). Although clear clinical efficacy has been demonstrated with antitumor antibodies since the late 1990s, other immunotherapies had not been shown to be effective until recently, when a spate of successes established the broad potential of this therapeutic modality. These successes are based on fundamental scientific advances demonstrating the toleragenic nature of cancer and the pivotal role of the tumor immune microenvironment in suppressing antitumor immunity. New therapies based on a sophisticated knowledge of immune-suppressive cells, soluble factors, and signaling pathways are designed to break tolerance and reactivate antitumor immunity to induce potent, long-lasting responses. Preclinical models indicate the importance of a complex integrated immune response in eliminating established tumors and validate the exploration of combinatorial treatment regimens, which are anticipated to be far more effective than monotherapies. Unlike conventional cancer therapies, most immunotherapies are active and dynamic, capable of inducing immune memory to propagate a successful rebalancing of the equilibrium between tumor and host.
T cell differentiation into distinct functional effector and inhibitory subsets is regulated, in part, by the cytokine environment present at the time of antigen recognition. Here, we show that ...hypoxia-inducible factor 1 (HIF-1), a key metabolic sensor, regulates the balance between regulatory T cell (Tᵣₑg) and TH17 differentiation. HIF-1 enhances TH17 development through direct transcriptional activation of RORγt and via tertiary complex formation with RORγt and p300 recruitment to the IL-17 promoter, thereby regulating TH17 signature genes. Concurrently, HIF-1 attenuates Tᵣₑg development by binding Foxp3 and targeting it for proteasomal degradation. Importantly, this regulation occurs under both normoxic and hypoxic conditions. Mice with HIF-1α-deficient T cells are resistant to induction of TH17-dependent experimental autoimmune encephalitis associated with diminished TH17 and increased Tᵣₑg cells. These findings highlight the importance of metabolic cues in T cell fate determination and suggest that metabolic modulation could ameliorate certain T cell-based immune pathologies.
With recent approvals for multiple therapeutic antibodies that block cytotoxic T lymphocyte associated antigen 4 (CTLA4) and programmed cell death protein 1 (PD1) in melanoma, non-small-cell lung ...cancer and kidney cancer, and additional immune checkpoints being targeted clinically, many questions still remain regarding the optimal use of drugs that block these checkpoint pathways. Defining biomarkers that predict therapeutic effects and adverse events is a crucial mandate, highlighted by recent approvals for two PDL1 diagnostic tests. Here, we discuss biomarkers for anti-PD1 therapy based on immunological, genetic and virological criteria. The unique biology of the CTLA4 immune checkpoint, compared with PD1, requires a different approach to biomarker development. Mechanism-based insights from such studies may guide the design of synergistic treatment combinations based on immune checkpoint blockade.
BackgroundThe PD-1/PD-L1 checkpoint is a central mediator of immunosuppression in the tumor immune microenvironment (TME) and is primarily associated with IFN-g signaling. To characterize other ...factors regulating PD-L1 expression on tumor and/or immune cells, we investigated TME-resident cytokines and the role of transcription factors in constitutive and cytokine-induced PD-L1 expression.MethodsThirty-four cultured human tumor lines 18 melanomas (MEL), 12 renal cell carcinomas (RCC), 3 squamous cell carcinomas of the head and neck (SCCHN), and 1 non-small-cell lung carcinoma (NSCLC) and peripheral blood monocytes (Monos) were treated with cytokines that we detected in the PD-L1+ TME by gene expression profiling, including IFN-g, IL-1a, IL-10, IL-27 and IL-32g. PD-L1 cell surface protein expression was detected by flow cytometry, and mRNA by quantitative real-time PCR. Total and phosphorylated STAT1, STAT3, and p65 proteins were detected by Western blotting, and the genes encoding these proteins were knocked down with siRNAs. Additionally, the proximal promoter region of PDL1 (CD274) was sequenced in 33 cultured tumors.ResultsPD-L1 was constitutively expressed on 1/17 cultured MELs, 8/11 RCCs, 3/3 SCCHNs, and on Monos. Brief IFN-g exposure rapidly induced PD-L1 on all tumor cell lines and Monos regardless of constitutive PD-L1 expression. PD-L1 mRNA levels were associated with protein expression, which was diminished by exposure to transcriptional inhibitors. siRNA knockdown of STAT1 but not STAT3 reduced IFN-g- and IL-27-induced PD-L1 protein expression on tumor cells. In contrast, STAT3 knockdown in Monos reduced IL-10-induced PD-L1 protein expression, and p65 knockdown in tumor cells reduced IL-1a-induced PD-L1 expression. Notably, constitutive PD-L1 expression was not affected by knocking down STAT1, STAT3, or p65. Differential effects of IFN-g, IL-1a, and IL-27 on individual tumor cell lines were not due to PDL1 promoter polymorphisms.ConclusionsMultiple cytokines found in an immune-reactive TME may induce PD-L1 expression on tumor and/or immune cells through distinct signaling mechanisms. Factors driving constitutive PD-L1 expression were not identified in this study. Understanding complex mechanisms underlying PD-L1 display in the TME may allow treatment approaches mitigating expression of this immunosuppressive ligand, to enhance the impact of PD-1 blockade.
Nivolumab was assessed in patients with virus-associated tumors in the phase I/II CheckMate 358 trial (ClinicalTrials.gov identifier: NCT02488759). We report on patients with recurrent/metastatic ...cervical, vaginal, or vulvar cancers.
Patients received nivolumab 240 mg every 2 weeks. Although patients with unknown human papillomavirus status were enrolled, patients known to have human papillomavirus-negative tumors were ineligible. The primary end point was objective response rate. Duration of response (DOR), progression-free survival, and overall survival were secondary end points. Safety and patient-reported outcomes were exploratory end points.
Twenty-four patients (cervical, n = 19; vaginal/vulvar, n = 5) were enrolled. Most patients had received prior systemic therapy for metastatic disease (cervical, 78.9%; vaginal/vulvar, 80.0%). Objective response rates were 26.3% (95% CI, 9.1 to 51.2) for cervical cancer and 20.0% (95% CI, 0.5 to 71.6) for vaginal/vulvar cancers. At a median follow-up of 19.2 months, median DOR was not reached (range, 23.3 to 29.5+ months; + indicates a censored observation) in the five responding patients in the cervical cohort; the DOR was 5.0 months in the single responding patient in the vaginal/vulvar cohort. Median overall survival was 21.9 months (95% CI, 15.1 months to not reached) among patients with cervical cancer. Any-grade treatment-related adverse events were reported in 12 of 19 patients (63.2%) in the cervical cohort and all five patients in the vaginal/vulvar cohort; there were no treatment-related deaths. In the cervical cohort, nivolumab treatment generally resulted in stabilization of patient-reported outcomes associated with health status and health-related quality of life.
The efficacy of nivolumab in patients with recurrent/metastatic cervical and vaginal or vulvar cancers is promising and warrants additional investigation. No new safety signals were identified with nivolumab treatment in this population.
The PD-1 pathway, comprising the immune cell co-receptor Programmed Death 1 (PD-1) and its ligands, PD-L1 (B7-H1) and PD-L2 (B7-DC), mediates local immunosuppression in the tumor microenvironment. ...Drugs designed to block PD-1 or PD-L1 "release the brakes" on anti-tumor immunity and have demonstrated clinical activity in several types of advanced cancers, validating this pathway as a target for cancer therapy. Two such drugs have recently been approved to treat melanoma and lung cancers, and regulatory approvals in first- and second-line settings for additional cancer types are anticipated. The manageable safety profile of PD-1/PD-L1 blocking drugs identifies them as suitable for outpatient administration and the development of combinatorial therapies. Ongoing studies aim to identify biomarkers to guide patient selection, which would further improve the risk:benefit ratio for these drugs.
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