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Siew-leng Melinda Teng

Bio: Siew-leng Melinda Teng is an academic researcher from Genentech. The author has contributed to research in topics: Bladder cancer & Myeloid. The author has an hindex of 5, co-authored 6 publications receiving 2051 citations.
Topics: Bladder cancer, Myeloid, Antigen, Antibody, Monoclonal

Papers
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Journal ArticleDOI
27 Nov 2014-Nature
TL;DR: It is demonstrated that tumours expressing PD-L1-positive tumour-infiltrating immune cells had particularly high response rates, and patients with UBC, who are often older and have a higher incidence of renal impairment, may be better able to tolerate MPDL3280A versus chemotherapy.
Abstract: There have been no major advances for the treatment of metastatic urothelial bladder cancer (UBC) in the last 30 years. Chemotherapy is still the standard of care. Patient outcomes, especially for those in whom chemotherapy is not effective or is poorly tolerated, remain poor. One hallmark of UBC is the presence of high rates of somatic mutations. These alterations may enhance the ability of the host immune system to recognize tumour cells as foreign owing to an increased number of antigens. However, these cancers may also elude immune surveillance and eradication through the expression of programmed death-ligand 1 (PD-L1; also called CD274 or B7-H1) in the tumour microenvironment. Therefore, we examined the anti-PD-L1 antibody MPDL3280A, a systemic cancer immunotherapy, for the treatment of metastatic UBC. MPDL3280A is a high-affinity engineered human anti-PD-L1 monoclonal immunoglobulin-G1 antibody that inhibits the interaction of PD-L1 with PD-1 (PDCD1) and B7.1 (CD80). Because PD-L1 is expressed on activated T cells, MPDL3280A was engineered with a modification in the Fc domain that eliminates antibody-dependent cellular cytotoxicity at clinically relevant doses to prevent the depletion of T cells expressing PD-L1. Here we show that MPDL3280A has noteworthy activity in metastatic UBC. Responses were often rapid, with many occurring at the time of the first response assessment (6 weeks) and nearly all were ongoing at the data cutoff. This phase I expansion study, with an adaptive design that allowed for biomarker-positive enriched cohorts, demonstrated that tumours expressing PD-L1-positive tumour-infiltrating immune cells had particularly high response rates. Moreover, owing to the favourable toxicity profile, including a lack of renal toxicity, patients with UBC, who are often older and have a higher incidence of renal impairment, may be better able to tolerate MPDL3280A versus chemotherapy. These results suggest that MPDL3280A may have an important role in treating UBC-the drug received breakthrough designation status by the US Food and Drug Administration (FDA) in June 2014.

2,101 citations

Journal ArticleDOI
TL;DR: PD-L1 expression is prevalent in this disease and may protect cancer cells from immune-mediated degranulation, leading to a poor prognosis and limited treatment options.
Abstract: 5011 Background: Metastatic UBC is associated with a poor prognosis and limited treatment options. PD-L1 expression is prevalent in this disease and may protect cancer cells from immune-mediated de...

109 citations

Journal ArticleDOI
TL;DR: PD-L1 may contribute to immune escape in UBC, a disease of high mutational complexity and immunogenicity and MPDL3280A was designed to restore T cell–mediated antitumor activity by restoring PD-L 1 activity.
Abstract: 4501 Background: PD-L1 may contribute to immune escape in UBC, a disease of high mutational complexity and immunogenicity. MPDL3280A was designed to restore T cell–mediated antitumor activity by bl...

67 citations

Journal ArticleDOI
TL;DR: MPDL3280A is a PD-L1-targeting antibody with an engineered Fc domain that disrupts PD- l1/PD-1 and PD- L1/B7.1 signaling that may inhibit immune-mediated antitumor responses in metastatic urothelial bladder cancer.
Abstract: 297 Background: Metastatic urothelial bladder cancer (UBC) is a mutationally-complex disease in which PD-L1 expression in the tumor microenvironment may inhibit immune-mediated antitumor responses. MPDL3280A is a PD-L1-targeting antibody with an engineered Fc domain that disrupts PD-L1/PD-1 and PD-L1/B7.1 signaling. Methods: MPDL3280A was studied in a phase Ia metastatic UBC expansion cohort. UBC pts received MPDL3280A 15 mg/kg IV q3w for ≤16 cycles. Efficacy-evaluable pts were dosed by January 27, 2014 (≥12 week follow-up) with a data cutoff of April 21, 2014. RECIST v1.1 was used to assess ORR. PD-L1 expression (by immune cell IHC) was centrally evaluated from archival biopsies. In-tumor gene expression and peripheral biomarker analyses were done on pts dosed by Nov 20, 2013, with a cutoff of January 1, 2014. Results: In the UBC cohort, 33 IHC 2/3 pts, 36 IHC 0/1 pts, and 1 PD-L1 pt with unknown IHC were efficacy-evaluable. Median pt age was 65 y (36-89), and 73% were male. Visceral and liver metastases...

11 citations

Journal ArticleDOI
TL;DR: In this article, gene expression analyses of metastatic urothelial bladder cancer (UBC) patients were conducted to interrogate the tumor immune microenvironment in PD-L1-positive tumors and to identify potential mechanisms associated with response or resistance to MPDL3280A.
Abstract: Treatment options for metastatic urothelial bladder cancer (UBC) are limited. Mutational complexity is known to be high in UBC and may correlate with increased immunogenicity. MPDL3280A, a human PD-L1 monoclonal antibody containing an engineered Fc-domain designed to promote a Th1-driven response, has demonstrated a RECIST response rate of 43% in diagnostically selected, pretreated patients with UBC. A total of 68 patients (67 with efficacy evaluable) were enrolled in the UBC cohort of the Phase I study; 45% were PD-L1 IHC diagnostic positive as defined by expression of PD-L1 on ≥ 5% of tumor-infiltrating immune cells. In the prescreened UBC population, the prevalence of PD-L1-positive patients was 27%. Comprehensive gene expression analyses of UBC tumors were conducted to interrogate the tumor immune microenvironment in PD-L1-positive tumors and to identify potential mechanisms associated with response or resistance to MPDL3280A. In this study, PD-L1-positive tumors exhibited a high prevalence of gene expression markers associated with T-effector cells (Teff), including perforin, IFNγ, CD8A, granzyme B, granzyme A and EOMES. Additionally, a low baseline signature of genes associated with myeloid cell markers, including IL1B and IL8, appeared to be statistically significantly associated (P<0.01) with MPDL3280A response, suggesting a potential role for myeloid biology in resistance to MPDL3280A treatment in UBC. Tumor burden markers, including CA-125, CA19-9 and human chorionic gonadotropin (HCG), have been associated with chemotherapy response markers in UBC. A marked decrease in these markers, including CEA, CA19-9, CA-125 and HCG, was observed with MPDL3280A response after 1 treatment cycle, potentially enabling an on-treatment monitoring alternative for response to therapy. Similarly, evaluation of cytokines on treatment identified markers, including IL-6 and IL-10, elevated as early as Cycle 2 only in patients without response to MPDL3280A. These circulating cytokines and tumor-associated gene signatures suggest potential mechanisms associated with resistance and response to MPDL3280A in UBC and provide a rationale for informed combination strategies to further improve treatment benefit in this indication.

6 citations


Cited by
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Journal ArticleDOI
TL;DR: This study showed that mismatch-repair status predicted clinical benefit of immune checkpoint blockade with pembrolizumab, and high somatic mutation loads were associated with prolonged progression-free survival.
Abstract: BackgroundSomatic mutations have the potential to encode “non-self” immunogenic antigens. We hypothesized that tumors with a large number of somatic mutations due to mismatch-repair defects may be susceptible to immune checkpoint blockade. MethodsWe conducted a phase 2 study to evaluate the clinical activity of pembrolizumab, an anti–programmed death 1 immune checkpoint inhibitor, in 41 patients with progressive metastatic carcinoma with or without mismatch-repair deficiency. Pembrolizumab was administered intravenously at a dose of 10 mg per kilogram of body weight every 14 days in patients with mismatch repair–deficient colorectal cancers, patients with mismatch repair–proficient colorectal cancers, and patients with mismatch repair–deficient cancers that were not colorectal. The coprimary end points were the immune-related objective response rate and the 20-week immune-related progression-free survival rate. ResultsThe immune-related objective response rate and immune-related progression-free survival ...

6,835 citations

Journal ArticleDOI
03 Apr 2015-Science
TL;DR: Treatment efficacy was associated with a higher number of mutations in the tumors, and a tumor-specific T cell response paralleled tumor regression in one patient, suggesting that the genomic landscape of lung cancers shapes response to anti–PD-1 therapy.
Abstract: Immune checkpoint inhibitors, which unleash a patient’s own T cells to kill tumors, are revolutionizing cancer treatment. To unravel the genomic determinants of response to this therapy, we used whole-exome sequencing of non–small cell lung cancers treated with pembrolizumab, an antibody targeting programmed cell death-1 (PD-1). In two independent cohorts, higher nonsynonymous mutation burden in tumors was associated with improved objective response, durable clinical benefit, and progression-free survival. Efficacy also correlated with the molecular smoking signature, higher neoantigen burden, and DNA repair pathway mutations; each factor was also associated with mutation burden. In one responder, neoantigen-specific CD8+ T cell responses paralleled tumor regression, suggesting that anti–PD-1 therapy enhances neoantigen-specific T cell reactivity. Our results suggest that the genomic landscape of lung cancers shapes response to anti–PD-1 therapy.

6,215 citations

Journal ArticleDOI
TL;DR: Pembrolizumab had an acceptable side-effect profile and showed antitumor activity in patients with advanced non-small-cell lung cancer and PD-L1 expression in at least 50% of tumor cells correlated with improved efficacy of pembrolIZumab.
Abstract: BackgroundWe assessed the efficacy and safety of programmed cell death 1 (PD-1) inhibition with pembrolizumab in patients with advanced non–small-cell lung cancer enrolled in a phase 1 study. We also sought to define and validate an expression level of the PD-1 ligand 1 (PD-L1) that is associated with the likelihood of clinical benefit. MethodsWe assigned 495 patients receiving pembrolizumab (at a dose of either 2 mg or 10 mg per kilogram of body weight every 3 weeks or 10 mg per kilogram every 2 weeks) to either a training group (182 patients) or a validation group (313 patients). We assessed PD-L1 expression in tumor samples using immunohistochemical analysis, with results reported as the percentage of neoplastic cells with staining for membranous PD-L1 (proportion score). Response was assessed every 9 weeks by central review. ResultsCommon side effects that were attributed to pembrolizumab were fatigue, pruritus, and decreased appetite, with no clear difference according to dose or schedule. Among all ...

4,834 citations

Journal ArticleDOI
27 Nov 2014-Nature
TL;DR: Evaluated data suggest that MPDL3280A is most effective in patients in which pre-existing immunity is suppressed by PD-L1, and is re-invigorated on antibody treatment, as well as across multiple cancer types.
Abstract: The development of human cancer is a multistep process characterized by the accumulation of genetic and epigenetic alterations that drive or reflect tumour progression. These changes distinguish cancer cells from their normal counterparts, allowing tumours to be recognized as foreign by the immune system. However, tumours are rarely rejected spontaneously, reflecting their ability to maintain an immunosuppressive microenvironment. Programmed death-ligand 1 (PD-L1; also called B7-H1 or CD274), which is expressed on many cancer and immune cells, plays an important part in blocking the 'cancer immunity cycle' by binding programmed death-1 (PD-1) and B7.1 (CD80), both of which are negative regulators of T-lymphocyte activation. Binding of PD-L1 to its receptors suppresses T-cell migration, proliferation and secretion of cytotoxic mediators, and restricts tumour cell killing. The PD-L1-PD-1 axis protects the host from overactive T-effector cells not only in cancer but also during microbial infections. Blocking PD-L1 should therefore enhance anticancer immunity, but little is known about predictive factors of efficacy. This study was designed to evaluate the safety, activity and biomarkers of PD-L1 inhibition using the engineered humanized antibody MPDL3280A. Here we show that across multiple cancer types, responses (as evaluated by Response Evaluation Criteria in Solid Tumours, version 1.1) were observed in patients with tumours expressing high levels of PD-L1, especially when PD-L1 was expressed by tumour-infiltrating immune cells. Furthermore, responses were associated with T-helper type 1 (TH1) gene expression, CTLA4 expression and the absence of fractalkine (CX3CL1) in baseline tumour specimens. Together, these data suggest that MPDL3280A is most effective in patients in which pre-existing immunity is suppressed by PD-L1, and is re-invigorated on antibody treatment.

4,227 citations

Journal ArticleDOI
03 Apr 2015-Science
TL;DR: The way forward for this class of novel agents lies in the ability to understand human immune responses in the tumor microenvironment, which will provide valuable information regarding the dynamic nature of the immune response and regulation of additional pathways that will need to be targeted through combination therapies to provide survival benefit for greater numbers of patients.
Abstract: Immune checkpoint therapy, which targets regulatory pathways in T cells to enhance antitumor immune responses, has led to important clinical advances and provided a new weapon against cancer. This therapy has elicited durable clinical responses and, in a fraction of patients, long-term remissions where patients exhibit no clinical signs of cancer for many years. The way forward for this class of novel agents lies in our ability to understand human immune responses in the tumor microenvironment. This will provide valuable information regarding the dynamic nature of the immune response and regulation of additional pathways that will need to be targeted through combination therapies to provide survival benefit for greater numbers of patients.

3,499 citations