Analyses of PD-L1 and Inflammatory Gene Expression Association with Efficacy of Nivolumab ± Ipilimumab in Gastric Cancer/Gastroesophageal Junction Cancer

PURPOSE

In advanced gastric cancer/gastroesophageal junction cancer (GC/GEJC), there is a need to identify biomarkers of response to therapies, such as immune checkpoint inhibitors.

PATIENTS AND METHODS

In post hoc exploratory analyses from CheckMate 032 (GC/GEJC cohort), we evaluated associations between nivolumab ± ipilimumab (NIVO ± IPI) efficacy and programmed death ligand 1 (PD-L1) expression, defined by tumor cells (% TC) or combined positive score (CPS; sum of PD-L1-staining TCs + immune cells, divided by total viable TCs, × 100) using the Dako PD-L1 IHC 28-8 pharmDx assay, or inflammatory gene expression.

RESULTS

There was a trend toward increased efficacy (objective response and overall survival) when PD-L1 expression was determined by CPS compared with % TC at higher cutoffs of ≥5 and ≥10 in the pooled analysis of all treatment regimens. In this analysis, 19% and 26% of patients with PD-L1-positive tumors at a CPS cutoff of ≥5 and ≥10, respectively, had an objective response compared with 8% and 9% of patients at the equivalent % TC cutoffs. Longer survival was demonstrated in patients with PD-L1-positive (defined by CPS cutoffs of ≥5 and ≥10) versus PD-L1-negative status. Similar results were observed in the NIVO 1 mg/kg + IPI 3 mg/kg subgroup. Multiple inflammatory gene signatures/transcripts, including a signature consisting of four genes (CD274, CD8A, LAG3, and STAT1), showed associations with response to NIVO ± IPI.

CONCLUSIONS

This study suggests a greater association of PD-L1 expression by CPS with NIVO ± IPI efficacy compared with % TC PD-L1 expression in patients with GC/GEJC. Inflammatory signatures were also associated with NIVO ± IPI response, warranting further investigation.See related commentary by Moutafi and Rimm, p. 3812.

Association of inflammatory biomarkers with clinical outcomes in nivolumab-treated patients with advanced hepatocellular carcinoma

BACKGROUND & AIMS

Nivolumab, a programmed death (PD)-1 (PD-1) inhibitor, led to durable responses, manageable safety, and increased survival in patients with advanced hepatocellular carcinoma (HCC). In our retrospective analysis, we studied the immunobiology and potential associations between biomarkers and outcomes with nivolumab in HCC.

METHODS

Fresh and archival tumour samples from dose-escalation and dose-expansion phases of the CheckMate 040 trial were analysed by immunohistochemistry and RNA sequencing to assess several inflammatory gene expression signatures, including CD274 (PD-ligand 1 [PD-L1]), CD8A, LAG3, and STAT1. Biomarkers were assessed for association with clinical outcomes (best overall response by blinded independent central review per RECIST v1.1 and overall survival [OS]).

RESULTS

Complete or partial tumour responses were observed in PD-L1-positive and PD-L1-negative patients treated with nivolumab monotherapy. Median OS was 28.1 (95% CI 18.2-n.a.) vs. 16.6 months (95% CI 14.2-20.2) for patients with tumour PD-L1 ≥1% vs. <1% (p = 0.03). Increased CD3 and CD8 showed a non-significant trend towards improved OS (both p = 0.08), and macrophage markers were not associated with OS. Tumour PD-1 and PD-L1 expression were associated with improved OS (p = 0.05 and p = 0.03, respectively). An inflammatory gene signature consisting of 4 genes was associated with improved objective response rate (p = 0.05) and OS (p = 0.01).

CONCLUSIONS

PD-1 and PD-L1 expression, biomarkers of inflammation, and inflammatory gene signatures trended with improved survival and response. While further confirmation within a larger phase III trial is needed to evaluate predictive value of these biomarkers, these exploratory analyses suggest that anti-tumour immune response may play a role in the treatment benefit of nivolumab in HCC.

LAY SUMMARY

Certain tests may be used to provide a picture of how a tumour is escaping the immune system, allowing it to continue to grow and create more tumours. Therapies such as nivolumab are designed to help the immune system fight the tumour. These tests may be used to determine how effective such therapies will be in the treatment of advanced liver cancer.

NCT NUMBER

NCT01658878.

Abstract 2673: Association of PD-L1 combined positive score and immune gene signatures with efficacy of nivolumab (NIVO) ± ipilimumab (IPI) in patients with metastatic gastroesophageal cancer (mGEC)

Background: In the CheckMate 032 phase 1/2 study, NIVO ± IPI demonstrated clinically meaningful antitumor activity in patients with chemotherapy-refractory mGEC. Archival or fresh tumor biopsies were analyzed to determine whether expression of PD-L1 and selected immune gene signatures were predictive of response to NIVO ± IPI. Methods: Pooled analyses included all treatment regimens (NIVO 3 mg/kg, NIVO 1 mg/kg + IPI 3 mg/kg, NIVO 3 mg/kg + IPI 1 mg/kg, and patients treated with NIVO 1 mg/kg + IPI 1 mg/kg in the dose-escalation phase). PD-L1 immunohistochemistry (IHC; Dako PD-L1 IHC 28-8 pharmDx assay) was used to evaluate tumor PD-L1 expression, referred to as tumor proportion score (TPS). Combined positive score (CPS) was determined by evaluating PD-L1 expression on previously stained IHC slides using the CPS algorithm. Gene expression profiling (GEP) by RNA sequencing was used to evaluate immune cell activation and infiltration signatures, a Bristol-Myers Squibb (BMS) inflammatory signature, and PD-L1 gene expression. Results: The pooled CPS (N = 104), TPS (N = 130), and GEP (N = 40) cohorts were mostly representative of the overall CheckMate 032 mGEC cohort (N =163). At a median (range) follow-up of 23.4 (17.0-35.4) months, CPS at higher cutoffs correlated better with efficacy and had higher prevalence than TPS in all analyses (Table). For all immune gene signatures examined, responders had higher signature scores in aggregate. For the BMS inflammatory signature, the association between signature score and response was significant (P = 0.004; false discovery rate = 0.037). Conclusions: CPS demonstrated stronger association with efficacy of NIVO ± IPI than TPS in mGEC. Prevalence of CPS was higher than that of TPS. Among immune gene signatures examined, the BMS inflammatory signature achieved the best association with efficacy and warrants further investigation.

All treatments combinedMethodNCutoffResponse rate, %Prevalence, %All patients163NA9.8100CPS1041026.533519.250114.168TPS130109.1857.710117.531NIVO 1 mg/kg + IPI 3 mg/kgMethodNCutoffResponse rate, %Prevalence, %All patients49NA20.4100CPS331054.533541.252128.076TPS421002502140.024CPS = combined positive score (number of PD-L1-staining tumor cells, lymphocytes, and macrophages relative to all viable tumor cells x 100); IPI = ipilimumab; NA, not applicable; NIVO = nivolumab; TPS = tumor proportion score

Citation Format: Ming Lei, Nathan Siemers, Dimple Pandya, Han Chang, Teresa Sanchez, Cecile Dorange, Christopher Harbison, Peter M. Szabo, Yelena Janjigian, Patrick A. Ott, Padmanee Sharma, Johanna Bendell, Jeffry Evans, Filippo de Braud, Ian Chau, Zachary Boyd. Association of PD-L1 combined positive score and immune gene signatures with efficacy of nivolumab (NIVO) ± ipilimumab (IPI) in patients with metastatic gastroesophageal cancer (mGEC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2673.

Current Status of Companion and Complementary Diagnostics: Strategic Considerations for Development and Launch

US Food and Drug Administration (FDA)‐approved diagnostic assays play an increasingly common role in managing patients to prolong lifespan while also enhancing quality of life. Diagnostic assays can be essential for the safe and effective use of therapeutics (companion diagnostic), or may inform on improving the benefit/risk ratio without restricting drug access (complementary diagnostic). This tutorial reviews strategic considerations for drug and assay development resulting in FDA‐approved companion or complementary diagnostic status.

Atezolizumab as first-line treatment in cisplatin-ineligible patients with locally advanced and metastatic urothelial carcinoma: a single-arm, multicentre, phase 2 trial

BACKGROUND

First-line chemotherapy for patients with cisplatin-ineligible locally advanced or metastatic urothelial carcinoma is associated with short response duration, poor survival, and high toxicity. This study assessed atezolizumab (anti-programmed death-ligand 1 [PD-L1]) as treatment for metastatic urothelial cancer in cisplatin-ineligible patients.

METHODS

For this single-arm, multicentre, phase 2 study, in 47 academic medical centres and community oncology practices in seven countries in North America and Europe, we recruited previously untreated patients with locally advanced or metastatic urothelial cancer who were cisplatin ineligible. Patients were given 1200 mg intravenous atezolizumab every 21 days until progression. The primary endpoint was independently confirmed objective response rate per Response Evaluation Criteria in Solid Tumors version 1.1 (central review), assessed in prespecified subgroups based on PD-L1 expression and in all patients. All participants who received one or more doses of atezolizumab were included in the primary and safety analyses. This study was registered with ClinicalTrials.gov, number NCT02108652.

FINDINGS

Between June 9, 2014, and March 30, 2015, we enrolled 123 patients, of whom 119 received one or more doses of atezolizumab. At 17·2 months' median follow-up, the objective response rate was 23% (95% CI 16 to 31), the complete response rate was 9% (n=11), and 19 of 27 responses were ongoing. Median response duration was not reached. Responses occurred across all PD-L1 and poor prognostic factor subgroups. Median progression-free survival was 2·7 months (2·1 to 4·2). Median overall survival was 15·9 months (10·4 to not estimable). Tumour mutation load was associated with response. Treatment-related adverse events that occurred in 10% or more of patients were fatigue (36 [30%] patients), diarrhoea (14 [12%] patients), and pruritus (13 [11%] patients). One treatment-related death (sepsis) occurred. Nine (8%) patients had an adverse event leading to treatment discontinuation. Immune-mediated events occurred in 14 (12%) patients.

INTERPRETATION

Atezolizumab showed encouraging durable response rates, survival, and tolerability, supporting its therapeutic use in untreated metastatic urothelial cancer.

FUNDING

F Hoffmann-La Roche, Genentech.

Clinical activity, safety, and biomarkers of MPDL3280A in metastatic urothelial bladder cancer: Additional analysis from phase IA study

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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 were present in 74% and 33% of pts, respectively. 73% had ≥2 prior therapies, and 91% had prior platinum. The unconfirmed ORR was 52% (95% CI, 34-69; 3 CRs, 14 PRs) in IHC 2/3 pts and 14% (95% CI, 6-28; 5 PRs) in IHC 0/1 pts. The median DOR was not yet reached (0.1+ to 42+ w in IHC 2/3 pts, n=17; 6+ to 19+ w in IHC 0/1 pts, n=5). 19/22 responding pts had ongoing responses. Median PFS was 24 w in IHC 2/3 pts (5 to 50+ w, n=33) and 8 w in IHC 0/1 pts (0.1+ to 30+ w, n=36). Of 74 pts evaluable for safety, all grade treatment-related AEs occurred in 65%, most often fatigue, decreased appetite and nausea. 5% had treatment-related G3-4 AEs. No treatment-related deaths were seen. The median follow-up was 5.4 mos (1+ to 12 mos, n=70). IHC 2/3 tumors had low expression of a baseline myeloid marker gene signature, including IL8 and IL1B, which was associated with MPLD3280A response. Additionally, circulating inflammatory markers (e.g., CRP) and tumor burden markers (e.g., HCG) decreased in responders by cycle 2. Updated data will be presented. Conclusions: MPDL3280A was well tolerated in UBC pts. Rapid and durable responses were seen and correlated with PD-L1 IHC status on immune cells. Biomarkers suggest a potential role for myeloid biology in primary resistance to MPDL3280A. Clinical trial information: NCT01375842.

MPDL3280A (anti-PD-L1) treatment leads to clinical activity in metastatic bladder cancer

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.

miR-221/222 targeting of trichorhinophalangeal 1 (TRPS1) promotes epithelial-to-mesenchymal transition in breast cancer

Compared with the luminal subtype, the basal-like subtype of breast cancer has an aggressive clinical behavior, but the reasons for this difference between the two subtypes are poorly understood. We identified microRNAs (miRNAs) miR-221 and miR-222 (miR-221/222) as basal-like subtype-specific miRNAs that decrease expression of epithelial-specific genes and increase expression of mesenchymal-specific genes. In addition, expression of these miRNAs increased cell migration and invasion, which collectively are characteristics of the epithelial-to-mesenchymal transition (EMT). The basal-like transcription factor FOSL1 (also known as Fra-1) directly stimulated the transcription of miR-221/222, and the abundance of these miRNAs decreased with inhibition of MEK (mitogen-activated or extracellular signal-regulated protein kinase kinase), placing miR-221/222 downstream of the RAS pathway. The miR-221/222-mediated reduction in E-cadherin abundance depended on their targeting of the 3' untranslated region (3'UTR) of TRPS1 (trichorhinophalangeal syndrome type 1), which is a member of the GATA family of transcriptional repressors. TRPS1 inhibited EMT by directly repressing expression of ZEB2 (Zinc finger E-box-binding homeobox 2). Therefore, miR-221/222 may contribute to the aggressive clinical behavior of basal-like breast cancers.

TRPS1 targeting by miR-221/222 promotes the epithelial-to-mesenchymal transition in breast cancer

The basal-like subtype of breast cancer has an aggressive clinical behavior compared to that of the luminal subtype. We identified the microRNAs (miRNAs) miR-221 and miR-222 (miR-221/222) as basal-like subtype-specific miRNAs and showed that expression of miR-221/222 decreased expression of epithelial-specific genes and increased expression of mesenchymal-specific genes, and increased cell migration and invasion in a manner characteristic of the epithelial-to-mesenchymal transition (EMT). The transcription factor FOSL1 (also known as Fra-1), which is found in basal-like breast cancers but not in the luminal subtype, stimulated the transcription of miR-221/222, and the abundance of these miRNAs decreased with inhibition of the epidermal growth factor receptor (EGFR) or MEK (mitogen-activated or extracellular signal-regulated protein kinase kinase), placing miR-221/222 downstream of the RAS pathway. Furthermore, miR-221/222-mediated reduction in E-cadherin abundance depended on their targeting the 3' untranslated region of the GATA family transcriptional repressor TRPS1 (tricho-rhino-phalangeal syndrome type 1), which inhibited EMT by decreasing ZEB2 (zinc finger E-box-binding homeobox2) expression. We conclude that by promoting EMT, miR-221/222 may contribute to the more aggressive clinical behavior of basal-like breast cancers.

Raccoon roundworm encephalitis

Raccoon roundworm encephalitis is a rare but devastating infection characterized by progressive neurological decline despite attempted therapy. Patients present with deteriorating neurological function, eosinophilia, and history of pica or geophagia resulting in ingestion of the parasite. Neuroimaging studies demonstrate nonspecific findings of progressive white matter inflammation and cortical atrophy.

In vivo antitumor activity of MEK and phosphatidylinositol 3-kinase inhibitors in basal-like breast cancer models

PURPOSE

The pathways underlying basal-like breast cancer are poorly understood, and as yet, there is no approved targeted therapy for this disease. We investigated the role of mitogen-activated protein kinase kinase (MEK) and phosphatidylinositol 3-kinase (PI3K) inhibitors as targeted therapies for basal-like breast cancer.

EXPERIMENTAL DESIGN

We used pharmacogenomic analysis of a large panel of breast cancer cell lines with detailed accompanying molecular information to identify molecular predictors of response to a potent and selective inhibitor of MEK and also to define molecular mechanisms underlying combined MEK and PI3K targeting in basal-like breast cancer. Hypotheses were confirmed by testing in multiple tumor xenograft models.

RESULTS

We found that basal-like breast cancer models have an activated RAS-like transcriptional program and show greater sensitivity to a selective inhibitor of MEK compared with models representative of other breast cancer subtypes. We also showed that loss of PTEN is a negative predictor of response to MEK inhibition, that treatment with a selective MEK inhibitor caused up-regulation of PI3K pathway signaling, and that dual blockade of both PI3K and MEK/extracellular signal-regulated kinase signaling synergized to potently impair the growth of basal-like breast cancer models in vitro and in vivo.

CONCLUSIONS

Our studies suggest that single-agent MEK inhibition is a promising therapeutic modality for basal-like breast cancers with intact PTEN, and also provide a basis for rational combination of MEK and PI3K inhibitors in basal-like cancers with both intact and deleted PTEN.

Transcriptional control of human T-BET expression: the role of Sp1

Murine T-bet (T-box expressed in T cells) is a master regulator of IFN-gamma gene expression in NK and T cells. T-bet also plays a critical role in autoimmunity, asthma and other diseases. However, cis elements or trans factors responsible for regulating T-bet expression remain largely unknown. Here, we report on our discovery of six Sp1-binding sites within the proximal human T-BET promoter that are highly conserved among mammalian species. Electrophoretic mobility shift assays demonstrate a physical association between Sp1 and the proximal T-BET promoter with a direct dose response between Sp1 expression and T-BET promoter activity. Ectopic overexpression of Sp1 also enhanced T-BET expression and cytokine-induced IFN-gamma secretion in NK cells and T cells. Mithramycin A, which blocks the binding of Sp1 to the T-BET promoter, diminished both T-BET expression and IFN-gamma protein production in monokine-stimulated primary human NK cells. Collectively, our results suggest that Sp1 is a positive transcriptional regulator of T-BET. As T-BET and IFN-gamma are critically important in inflammation, infection, and cancer, targeting Sp1, possibly with mithramycin A, may be useful for preventing and/or treating diseases associated with aberrant T-BET or IFN-gamma expression.

MRI tumor characterization using Gd-GlyMe-DOTA-perfluorooctyl-mannose-conjugate (Gadofluorine M), a protein-avid contrast agent

The rationale and objectives were to define the MRI tumor-characterizing potential of a new protein-avid contrast agent, Gd-GlyMe-DOTA-perfluorooctyl-mannose-conjugate (Gadofluorine M; Schering AG, Berlin, Germany) in a chemically induced tumor model of varying malignancy. Because of the tendency for this agent to form large micelles in water and to bind strongly to hydrophobic sites on proteins, it was hypothesized that patterns of dynamic tumor enhancement could be used to differentiate benign from malignant lesions, to grade the severity of malignancies and to define areas of tumor necrosis. Gadofluorine M, 0.05 mmol Gd kg(-1), was administered intravenously to 28 anesthetized rats that had developed over 10 months mammary tumors of varying degrees of malignancy as a consequence of intraperitoneal administration of N-ethyl-N-nitrosourea (ENU), 45-250 mg kg(-1). These tumors ranged histologically from benign fibroadenomas to highly undifferentiated adenocarcinomas. Dynamic enhancement data were analyzed kinetically using a two-compartment tumor model to generate estimates of fractional plasma volume (fPV), apparent fractional extracellular volume (fEV*) and an endothelial transfer coefficient (K(PS)) for this contrast agent. Tumors were examined microscopically for tumor type, degree of malignancy (Scarff-Bloom-Richardson score) and location of necrosis. Eighteen tumor-bearing rats were successfully imaged. MRI data showed an immediate strong and gradually increasing tumor enhancement. K(PS) and fEV*, but not fPV obtained from tumors correlated significantly (p < 0.05) with the SBR tumor grade, r = 0.65 and 0.56, respectively. Estimates for K(PS) and fEV* but not fPV were significantly lower in a group consisting of benign and low-grade malignant tumors compared with the group of less-differentiated high-grade tumors (1.61 +/- 0.64 vs 3.37 +/- 1.49, p < 0.01; 0.45 +/- 0.17 vs 0.78 +/- 0.24, p < 0.01; and 0.076 +/- 0.048 vs 0.121 +/- 0.088, p = 0.24, respectively). It is concluded that the protein-avid MRI contrast agent Gadofluorine M enhances tumors of varying malignancy depending on the tumor grade, higher contrast agent accumulation for more malignant lesions. The results show potential utility for differentiating benign and low-grade malignant lesions from high-grade cancers.

Pro- and antiinflammatory cytokine signaling: reciprocal antagonism regulates interferon-gamma production by human natural killer cells

Activated monocytes produce proinflammatory cytokines (monokines) such as interleukin (IL)-12, IL-15, and IL-18 for induction of interferon-gamma (IFN-gamma) by natural killer (NK) cells. NK cells provide the antiinflammatory cytokine transforming growth factor (TGF)-beta, an autocrine/negative regulator of IFN-gamma. The ability of one signaling pathway to prevail over the other is likely important in controlling IFN-gamma for the purposes of infection and autoimmunity, but the molecular mechanism(s) of how this counterregulation occurs is unknown. Here we show that in isolated human NK cells, proinflammatory monokines antagonize antiinflammatory TGF-beta signaling by downregulating the expression of the TGF-beta type II receptor, and its signaling intermediates SMAD2 and SMAD3. In contrast, TGF-beta utilizes SMAD2, SMAD3, and SMAD4 to suppress IFN-gamma and T-BET, a positive regulator of IFN-gamma. Indeed, activated NK cells from Smad3(-/-) mice produce more IFN-gamma in vivo than NK cells from wild-type mice. Collectively, our data suggest that pro- and antiinflammatory cytokine signaling reciprocally antagonize each other in an effort to prevail in the regulation of NK cell IFN-gamma production.