Safety and feasibility of immuno-cryotherapy

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Background: To investigate the safety and feasibility of image guided immuno-cryotherapy in patients with immune checkpoint inhibitor failure. Methods: Consecutive patients with primary or acquired failure to immune checkpoint inhibitor therapy were studied following treatment with concomitant image-guided cryotherapy and immune checkpoint inhibition. In addition to demographic features, type of malignancy, size of targeted metastatic lesion, number of cycles of cryotherapy, systemic immunotherapy, and adverse events in a 90 day post procedural window were extracted. The primary end point was safety and adverse events stratified by the common terminology for adverse events (CTCAE) criteria. As a secondary endpoint, efficacy of the cryotherapy was assessed by iRECIST. Results: Ten patients underwent combined image-guided cryotherapy and checkpoint immunotherapy between 2015 and 2017. Five patients received CTLA 4 blockade with cryotherapy, and 8 patients received PD1 axis blockade and cryotherapy. Six patients had metastatic non-small cell lung cancer and 4 had metastatic melanoma. Immunoprofiling demonstrated one patient each with a mutation in NRAS (G12C), NRAS (Q61R), KRAS (G12C), and ALK; and 2 with aBRAF V600E mutation. Cryotherapy was performed in immunotherapy failure sites, including liver (5) and adrenal glands (3), lymph node and muscle. The median size of targeted lesions was 4.5 cm (standard deviation 3.7cm). There were no grade 3 or higher adverse event, though 6 patients had grade 1 and 2 adverse effects in the periprocedural period which included fatigue, local pain, and poor appetite, isolated cases of diarrhea, colitis, pneumothorax, and procedural site hematoma. Regarding therapeutic response: 5 patients demonstrated partial response, 1 stable response, and 1 progression of disease. Two patients died in the followup period from non-treatment induced causes and 1 is awaiting follow-up. Disease control rate was 85.7%. Conclusions: Immuno-cryotherapy with immune checkpoint therapy in patients with immune checkpoint inhibitor resistance is safe and feasible in metastatic NSCLC and melanoma. There were no grade 3 or above adverse events.

Tumor Microvessel Density as a Prognostic Marker in High-Risk Renal Cell Carcinoma Patients Treated on ECOG-ACRIN E2805

Purpose: Increased vascularity is a hallmark of renal cell carcinoma (RCC). Microvessel density (MVD) is one measurement of tumor angiogenesis; however, its utility as a biomarker of outcome is unknown. ECOG-ACRIN 2805 (E2805) enrolled 1,943 resected high-risk RCC patients randomized to adjuvant sunitinib, sorafenib, or placebo. We aimed to determine the prognostic and predictive role of MVD in RCC.Experimental Design: We obtained pretreatment primary RCC nephrectomy tissues from 822 patients on E2805 and constructed tissue microarrays. Using quantitative immunofluorescence, we measured tumor MVD as the area of CD34-expressing cells. We determined the association with disease-free survival (DFS), overall survival (OS), treatment arm, and clinicopathologic variables.Results: High MVD (above the median) was associated with prolonged OS for the entire cohort (P = 0.021) and for patients treated with placebo (P = 0.028). The association between high MVD and OS was weaker in patients treated with sunitinib or sorafenib (P = 0.060). MVD was not associated with DFS (P = 1.00). On multivariable analysis, MVD remained independently associated with improved OS (P = 0.013). High MVD correlated with Fuhrman grade 1-2 (P < 0.001), clear cell histology (P < 0.001), and absence of necrosis (P < 0.001) but not with gender, age, sarcomatoid features, lymphovascular invasion, or tumor size.Conclusions: High MVD in resected high-risk RCC patients is an independent prognostic, rather than predictive, biomarker of improved OS. Further studies should assess whether incorporating MVD into clinical models will enhance our ability to predict outcome and if low MVD can be used for selection of high-risk patients for adjuvant therapy trials. Clin Cancer Res; 24(1); 217-23. ©2017 AACR.

Evolving Immunotherapy Approaches for Renal Cell Carcinoma

Metastatic renal cell carcinoma (mRCC) continues to be associated with high rates of morbidity and mortality. Renal cell carcinoma (RCC) is typically resistant to cytotoxic chemotherapy, and while targeted therapies have activity and prolong progression-free and overall survival, responses are usually not durable. Modulating the immune system with cytokine therapy, vaccine therapy, cell therapy, and checkpoint inhibitors offers hope of prolonged survival. Standard and emerging immune therapy approaches and combinations of immune therapies and other modalities are reviewed.

A phase 1/2 study of a novel IL-2 cytokine, NKTR-214, and nivolumab in patients with select locally advanced or metastatic solid tumors

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Background: NKTR-214 is a CD-122-biased agonist that targets the IL-2 pathway and is designed to provide sustained signaling through the heterodimeric IL-2 receptor pathway (IL-2Rβɣ) to preferentially activate and expand NK and effector CD8+ T cells over T regulatory cells within the tumor microenvironment. In a phase 1 monotherapy trial, pts treated with NKTR-214 demonstrated a substantial increase in CD8+ T and NK cells within the tumor microenvironment even when pretreated with multiple prior immunotherapeutic agents (abstract submitted). Based on this biomarker data and a favorable safety profile, a trial combining NKTR-214 and nivolumab was initiated. Methods: This is an on-going phase 1/2 study of NKTR-214 plus nivolumab in Pts with either melanoma (Mel), NSCLC, renal, bladder, or TNBC. Pts who are immunotherapy naïve or checkpoint therapy relapse/refractory are being studied separately. NKTR-214 and nivolumab are administered IV on a q2w or q3w schedule. Cohort 1 received NKTR-214 0.006 mg/kg q3w with nivolumab 240 mg q2w. Blood and tumor tissue were collected to measure immune activation using flow cytometry, immunohistochemistry, T cell clonality and gene expression analyses. Results: As of February 7, 2017, 5 Pts have been treated with the combination and all Pts were naïve to checkpoint inhibitors. There have been no dose limiting toxicities, no drug-related or immune related grade 3-5 adverse events (TRAEs) and no Pts have discontinued treatment. The most common TRAEs were pruritis and rash. Radiographic scans were available for 2 Pts. On treatment, Pt 1 with Mel had a mixed radiographic response at 1st scan, a ~40% decrease in LDH and a robust tumor immune cell infiltrate at week 3 the majority being newly proliferating CD8+ T cells expressing PD-1. Pt 2 with Mel had an unconfirmed complete response per RECIST 1.1 after 6 weeks of treatment; follow up tumor response data will be presented. Conclusions: Preliminary data demonstrate that NKTR-214 and nivolumab combination therapy is well tolerated with early evidence of clinical activity. Updated safety, pharmacokinetics, tumor response and biomarker data will be presented. Clinical trial information: NCT02983045.

Clinical results with combination of anti-CD27 agonist antibody, varlilumab, with anti-PD1 antibody nivolumab in advanced cancer patients

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Background: A phase 1 trial to assess the safety and immunological activity of the combination of varlilumab (V) and nivolumab (N), and recommend a dose of V for the phase 2 study was conducted. Methods: The study was performed using the approved dose of N (3 mg/kg Q2W) and escalating doses of V (0.1, 1, or 10 mg/kg Q2W) in anti-PD-(L)1 naïve patients with advanced cancer. Results: A total of 36 patients (21 CRC, 8 ovarian [OVA], 4 melanoma and 3 SCCHN) were enrolled. Toxicity was consistent with the safety profile of each agent individually; no unexpected toxicities were seen with the combination. No MTD was identified. An OVA cancer patient in the 10 mg/kg cohort had a DLT: hepatitis (G4) and acute kidney injury (G3). A CRC patient in the 10 mg/kg cohort had a drug-related SAE of mixed motor sensory neuropathy (G2) and a CRC patient in the 1 mg/kg cohort had rash (G3). No additional drug related SAEs or DLTs were reported. The majority of tumors were PD-L1 negative (24/27) by IHC at baseline. For patients with post treatment biopsies, PD-L1 expression was observed in 43.5% (10/23) and correlated with increases in CD8 T cell infiltration, consistent with the generation of anti-tumor immunity. Other treatment related biomarker changes included transient increases in serum chemokine levels, and a prominent decrease in circulating Tregs. Biomarker analysis did not clearly differentiate between dose levels, or delineate an optimal V dose. Three patients had objective PR by RECIST [CRC MSI-low (1 mg/kg V), SCCHN (10 mg/kg V) and OVA (10 mg/kg V, uPR)]. The response in the CRC patient is ongoing with a 94% decrease in target lesion diameter and a PFS of 19+ months. There were also 11 patients with SD. Phase 2 cohorts are ongoing in RCC, SCCHN, OVA, CRC and GBM. The Phase 2 portion includes exploration of different dose/regimens of V, including high and low exposure, to better characterize the optimal dosing strategy for V, in combination with a fixed dose of N (240 mg Q2W). Conclusions: The combination of V and N was well tolerated, associated with strong biological signals, and has evidence of clinical activity in subsets of patients with tumor types that are typically resistant to PD-1 inhibitor monotherapy. Clinical trial information: NCT02335918.

Microvessel density as a prognostic marker in high-risk renal cell carcinoma

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Background: Increased vascularity is a hallmark of renal cell carcinomas (RCC), particularly clear cell RCC. The vascular endothelial growth factor (VEGF) pathway, implicated in tumor angiogenesis, is dysregulated in RCC. The phase 3 trial ECOG-ACRIN E2805 enrolled 1,943 patients (pts) with resected high-risk RCC (pT1b high grade to pT4 any grade or N any). Pts were randomized to adjuvant sunitinib, sorafenib, or placebo. Our aim was to determine the prognostic and predictive role of microvessel density (MVD), VEGF receptors, and ligands in nephrectomy specimens. Methods: We obtainedpre-treatment primary RCC tissue from 822 pts and built tissue microarrays using 3 cores from each sample. Using quantitative immunofluorescence we measured tumor MVD (area of CD34-expressing cells) and intensity of the VEGF/VEGF-R family (VEGF-R1, R2, R3 and VEGF-A, B, C, D) in tumor cells. We tested for association with disease-free survival (DFS) and overall survival (OS) by the stratified log-rank test. Associations with treatment arm and clinicopathologic variables were determined. Results: High MVD (above the median) was associated with prolonged OS for the entire cohort (p = 0.021, HR 0.63) and for pts treated in the placebo group (p = 0.014). The association between high MVD and OS was weaker in patients treated with sunitinib or sorafenib (p = 0.060). High VEGFD expression overall was associated with shorter OS (p = 0.027) but not for placebo (p = 0.16). Yet high MVD was not associated with improved DFS (p = 1.00). High MVD correlated with above-median age ( > 56) (p = 0.032), Fuhrman grade I/II (p < 0.001), clear cell histology (p < 0.001), and absence of necrosis (p < 0.001) but not with gender, sarcomatoid features, lymphovascular invasion, or tumor size. In multivariable analysis, MVD remained independently associated with improved OS for the entire cohort (p = 0.013). Conclusions: High MVD in nephrectomy specimens of high-risk RCC pts is associated with improved OS, regardless of treatment arm. MVD is thus an independent prognostic, rather than predictive, biomarker. Further studies should assess whether incorporating MVD into clinical models will predict outcome in resected high-risk RCC pts and if MVD can be used for pt selection for adjuvant therapy.

A phase III randomized study of adjuvant ipilimumab (3 or 10 mg/kg) versus high-dose interferon alfa-2b for resected high-risk melanoma (U.S. Intergroup E1609): Preliminary safety and efficacy of the ipilimumab arms

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Background: In the U.S., 3 regimens have regulatory approval as adjuvant therapy for high-risk melanoma, including high-dose interferon-alfa (HDI) and ipilimumab 10 mg/kg (ipi10). Ipilimumab 3 mg/kg (ipi3) has regulatory approval for metastatic inoperable melanoma. The toxicity of ipi is dose- dependent, and following the recent approval of adjuvant ipi10, it has become urgent to evaluate the relative safety and efficacy of adjuvant ipi at the 2 dose levels that have been tested in E1609. Methods: E1609 randomized patients (pts) with resected high-risk melanoma (stratified by stages IIIB, IIIC, M1a, M1b) to ipi10 or ipi3 versus HDI. Co-primary endpoints were RFS and OS. The current analysis investigates the relative safety and preliminary, non-comparative RFS of the ipi arms as of 3/2/17. Results: E1609 was activated on 5/25/11 and completed adult pt accrual on 8/15/14. Accrual to ipi10 was suspended due to toxicity between 9/23-11/16/2013. Final adult pt accrual was 1670 including 511 ipi10, 636 HDI and 523 ipi3 pts. Treatment related adverse events (AEs) were reported among 503 ipi10 and 516 ipi3 pts. Worst degree (Gr 3+) AEs were experienced by 57% ipi10 and 36.4% ipi3 pts and were mostly immune related (Table 1). AEs led to discontinuation of treatment in 271 (53.8 %) of 503 ipi10 and in 180 (35.2 %) of 512 ipi3 pts during the initial 4 dose induction phase. Gr5 AEs considered at least possibly related were 8 with ipi10 and 2 with ipi3. At a median follow-up of 3.1 years, an unplanned RFS analysis of ipi3 and ipi10 on concurrently randomized pts showed no difference between the 2 arms. Three-year RFS rate was 54% (95% CI: 49, 60) with ipi10 and 56% (50, 61) with ipi3. Conclusions: Adjuvant therapy of pts with high-risk melanoma is associated with significantly more toxicity at ipi10 compared to ipi3. An unplanned RFS analysis of concurrently randomized pts on the 2 ipi arms showed no difference in RFS. Clinical trial information: NCT01274338. [Table: see text]

Effect of a novel IL-2 cytokine immune agonist (NKTR-214) on proliferating CD8+T cells and PD-1 expression on immune cells in the tumor microenvironment in patients with prior checkpoint therapy

2545

Background: NKTR-214 is a CD122-biased agonist designed to provide sustained signaling through the heterodimeric IL-2 receptor pathway (IL-2Rβɣ) to preferentially activate and expand effector CD8+ T and NK cells over T regulatory cells in the tumor microenvironment. Immune changes in the tumor microenvironment after NKTR-214 treatment was assessed in patients with locally advanced or metastatic solid tumors. Methods: NKTR-214 was administered IV in an outpatient setting q2w or q3w. Serial blood and tumor tissue samples were collected to measure immune activation using immunophenotyping including flow cytometry, immunohistochemistry (IHC), T cell clonality and gene expression analyses. Results: 26 patients (pts) have been treated with NKTR-214 at q3w, 4@0.003, 9@0.006, 6@0.009 and 1@0.012 mg/kg. Six pts received 0.006 mg/kg q2w. 58% of pts had prior immunotherapy. The most common Gr1-2 TRAEs were fatigue (73%) and pruritus (65%), and decreased appetite (46%). One pt experienced Gr3 syncope and hypotension at the highest dose tested and continued treatment at a lower dose. No drug-related AEs led to study discontinuation. No immune-related AEs or capillary leak syndrome were observed. 6 pts (23%) experienced tumor shrinkage from 10-30%. Three immunotherapy naïve pts receiving sequential anti-PD1 therapy, after ending treatment with NKTR-214, experienced significant tumor regression at first scan. In all pts evaluated, blood samples showed increases in newly proliferating (Ki67+) T and NK cells 8 days post dose. Flow cytometry and/or IHC revealed an up to 10-fold increase from baseline in tumor CD8+T and NK cells in the tumor microenvironment, with minimal changes to Tregs. PD-1 expression increased 2-fold in TILs. Gene expression analysis of tumor tissue showed increases in several immune checkpoint genes, cytotoxic markers (IFNg, PRF1, and GZMB), as well as a dynamic change in T cell clonality. Conclusions: Based on a favorable safety profile and strong correlative biomarker data, a phase 1/2 trial combining NKTR-214 and nivolumab is currently enrolling. Clinical trial information: NCT02869295.

Efficacy of single administration of tumor-infiltrating lymphocytes (TIL) in heavily pretreated patients with metastatic melanoma following checkpoint therapy

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Background: Adoptive cell therapy with TIL involves collection of autologous lymphocytes from the tumor via surgical resection, ex vivo expansion of TIL, lymphodepletion of the patient prior to infusion of TIL using Fludarabine and Cyclophosphamide, followed by infusion of TIL. Up to 6 doses of IL-2 (600,000 IU/kg) is administered to support multiplication of TIL and engraftment. Here, we present the preliminary results from an ongoing, multi-site Phase 2 study of TIL for advanced metastatic melanoma. Methods: Patients with advanced metastatic melanoma who have failed at least one prior systemic therapy were enrolled. Primary objective of the study was to characterize safety profile of LN-144. At baseline, patients had a median age of 56 (41-72) years; 44% were ≥ 60 years old. Median sum of tumor diameters for the target lesions was 10.4 cm, and median of 3 prior therapies. All enlisted patients had prior anti-PD1 as well as anti-CTLA4 and 67% had received ≥ 3 prior therapies. Responses were assessed by RECIST 1.1. TIL products were centrally manufactured. No complications arose from shipment of tumors or TIL. Results: Results are presented through 31 Jan 2017 for the first 9 infused patients evaluable by two assessments. Eight of 9 patients received all 6 doses of IL-2 per protocol. The most common (≥3 patients) non-hematologic grade 3-4 TEAE was hypophosphatemia. No neurotoxicity of grade ≥ 3 was reported. There were no deaths or discontinuations due to SAEs related to study treatment. ORR was 33% (CR = 11%, PR = 22%, SD = 22%, PD = 33%, NE = 11%). Mean time to best response was 3.0 months and median duration of follow up was 3.6 months (1.1+, 12.1). Responses were observed in patients with tumors carrying wild type or BRAF mutations. All patients demonstrated persistence of TIL on day 14 post-infusion. Conclusions: Cell therapy with TIL is an effective treatment with acceptable safety profile for advanced metastatic melanoma patients who are refractory to anti-PD1. TIL products can be centrally manufactured for broad clinical application. This study will be expanded to enroll patients with a shorter manufacturing process as well as offering retreatment for study patients. Clinical trial information: NCT02360579.

Nuclear IRF-1 expression as a mechanism to assess "Capability" to express PD-L1 and response to PD-1 therapy in metastatic melanoma

Background

Predictive biomarkers for antibodies against programmed death 1 (PD-1) remain a major unmet need in metastatic melanoma. Specifically, response is seen in tumors that do not express programmed death ligand 1 (PD-L1), highlighting the need for a more sensitive biomarker. We hypothesize that capacity to express PD-L1, as assessed by an assay for a PD-L1 transcription factor, interferon regulatory factor 1 (IRF-1), may better distinguish patients likely to benefit from anti-PD-1 immunotherapy.

Methods

Samples from 47 melanoma patients that received nivolumab, pembrolizumab, or combination ipilimumab/nivolumab at Yale New Haven Hospital from May 2013 to March 2016 were collected. Expression of IRF-1 and PD-L1 in archival pre-treatment formalin-fixed, paraffin-embedded tumor samples were assessed by the AQUA method of quantitative immunofluorescence. Objective radiographic response (ORR) and progression-free survival (PFS) were assessed using modified RECIST v1.1 criteria.

Results

Nuclear IRF-1 expression was higher in patients with partial or complete response (PR/CR) than in patients with stable or progressive disease (SD/PD) (p = 0.044). There was an insignificant trend toward higher PD-L1 expression in patients with PR/CR (p = 0.085). PFS was higher in the IRF-1-high group than the IRF-1-low group (p = 0.017), while PD-L1 expression had no effect on PFS (p = 0.83). In a subset analysis, a strong association with PFS is seen in patients treated with combination ipilimumab and nivolumab (p = 0.0051).

Conclusions

As a measure of PD-L1 expression capability, IRF-1 expression may be a more valuable predictive biomarker for anti-PD-1 therapy than PD-L1 itself.

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-017-0229-2) contains supplementary material, which is available to authorized users.

Comparing available criteria for measuring brain metastasis response to immunotherapy

The response assessment in neuro-oncology (RANO) working group recently proposed standardized response criteria for brain metastases (RANO-BM). We sought to compare RANO-BM to other criteria in an ongoing brain metastasis trial. The first 36 patients enrolled on NCT02085070, an ongoing trial of pembrolizumab for patients with untreated brain metastases, were included in this analysis. As RANO-BM had not been proposed when the protocol was written, response on trial was assessed using an institutional modification of RECIST 1.1 (mRECIST), wherein minimum target brain lesion size was 5 mm in longest diameter and up to five target brain lesions were followed. We here additionally assessed response using standard RECIST 1.1, RANO high-grade glioma (RANO-HGG), and RANO-BM. Comparison between the four criteria sets using cases eligible across the board revealed excellent concordance (kappa statistic > 0.8), with only one discordant case. However, compared to RECIST 1.1 or RANO-BM, using a 5 mm threshold for target brain lesions in mRECIST allowed enrollment of 13 additional patients, five of whom had durable responses. Compared to RANO-HGG, 19 additional patients were enrolled using mRECIST, eight of whom had durable responses. Consequently, this resulted in response rates ranging from 12% with RANO-HGG to 28% with mRECIST. This study supports using a 5 mm threshold for target brain lesions when using high resolution MRI with ≤2 mm slices to facilitate accrual to similar clinical trials and provide earlier access to novel therapies for brain metastasis patients. Concordance among the four criteria studied was otherwise very high.

Distinct dominant T-cell receptors with a tissue resident memory phenotype in individual melanoma metastases

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Background: Expression of inhibitory immune checkpoints (ICPs) within tumors has emerged as an important barrier for effective anti-tumor immunity. Antibody-mediated blockade of ICPs can lead to durable responses in patients. Interestingly, only a small subset of tumor infiltrating lymphocytes (TILs) express these checkpoints and there is a need to better understand the characteristics of this subset. We undertook this study to understand characteristics of TILs within melanoma. Methods: We used single cell mass cytometry, gene expression profiling of purified T cell subsets, T cell receptor (TCR) sequencing as well as functional studies to understand the characteristics of TILs in melanoma patients (n=50). We also performed exome sequencing of tumor cells in some patients. Results: We find that TILs are functionally and phenotypically distinct from circulating T cells. They express higher levels of inhibitory ICPs (PD-1, TIM-3) and secrete less IL2, IFNg and TNFa than T cells in circulation. Expression of vascular endothelial growth factor within tumors correlated with reduced T cell infiltration. Expression of ICPs (PD-1, TIM-3, PD-L1) were enriched in T cells with a phenotype and expression profile of tissue resident memory T (TRM) cells with most cells expressing multiple checkpoints. Within the myeloid compartment, ICPs were predominantly expressed on CD14+CD16+ subset. TCR sequencing revealed that individual melanoma metastases revealed that the top clones within each of the lesions have distinct TCRs. Concurrent TCR and tumor exome sequencing of individual metastases in the same patient revealed that inter-lesional diversity of TCRs exceeded differences in mutation/neoantigen load in tumor cells. Conclusions: Our findings suggest that TRM cells and CD16+ myeloid cells may be the major target of ICP blockade within tumors. The ability to activate, and retain TRM cells may be an important determinant of the T cell content of the tumor microenvironment and should be a goal for future vaccines. Importantly, our study illustrates inter-lesional diversity of TCRs within individual metastases which may differentially impact the outcome of immune therapy at each site.

PD-L1 Studies Across Tumor Types, Its Differential Expression and Predictive Value in Patients Treated with Immune Checkpoint Inhibitors

Purpose: With recent approval of inhibitors of PD-1 in melanoma, non-small cell lung cancer (NSCLC) and renal cell carcinoma, extensive efforts are under way to develop biomarkers predictive of response. PD-L1 expression has been most widely studied, and is more predictive in NSCLC than renal cell carcinoma or melanoma. We therefore studied differences in expression patterns across tumor types.Experimental Design: We used tissue microarrays with tumors from NSCLC, renal cell carcinoma, or melanoma and a panel of cell lines to study differences between tumor types. Predictive studies were conducted on samples from 65 melanoma patients treated with PD-1 inhibitors alone or with CTLA-4 inhibitors, characterized for outcome. PD-L1 expression was studied by quantitative immunofluorescence using two well-validated antibodies.Results: PD-L1 expression was higher in NSCLC specimens than renal cell carcinoma, and lowest in melanoma (P = 0.001), and this finding was confirmed in a panel of cell lines. In melanoma tumors, PD-L1 was expressed either on tumor cells or immune-infiltrating cells. The association between PD-L1 expression in immune-infiltrating cells and progression-free or overall-survival in melanoma patients treated with ipilimumab and nivolumab was stronger than PD-L1 expression in tumor cells, and remained significant on multivariable analysis.Conclusions: PD-L1 expression in melanoma tumor cells is lower than NSCLC or renal cell carcinoma cells. The higher response rate in melanoma patients treated with PD-1 inhibitors is likely related to PD-L1 in tumor-associated inflammatory cells. Further studies are warranted to validate the predictive role of inflammatory cell PD-L1 expression in melanoma and determine its biological significance. Clin Cancer Res; 23(15); 4270-9. ©2017 AACR.

Effect of NKTR-214 on the number and activity of CD8+ tumor infiltrating lymphocytes in patients with advanced renal cell carcinoma

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Background: Patients with low baseline CD8+ T-cells within the tumor microenvironment (TILs) have a poor response to immune checkpoint inhibitors. Agents designed to specifically activate and expand CD8+ T cells may improve clinical outcomes in patients with low TILs. NKTR-214 is a CD-122-biased agonist designed to provide sustained signaling through the heterodimeric IL-2 receptor pathway (IL-2Rβɣ) and preferentially activate and expand NK and effector CD8+ T cells over CD4+ T regulatory cells. Methods: A dose escalation, open-label, trial was initiated to assess the safety of NKTR-214 and explore immune changes in the blood and tumor microenvironment in patients with advanced solid tumors. NKTR-214 was administered IV in an outpatient setting with initial dosing at 0.003 mg/kg. Pre and post treatment blood and tumor samples were analyzed for immune phenotyping, gene expression, T cell receptor diversity, and changes in the tumor microenvironment by immunohistochemistry. Results: Among 25 patients dosed, 15 had RCC (10@0.006mg/kg, 4@0.009mg/kg, and 1@0.012mg/kg). Treatment with NKTR-214 was well tolerated and the MTD was not reached. One patient experienced DLTs (Gr3 syncope and hypotension) at 0.012 mg/kg. There were no immune-related AEs. Of 12 patients evaluable for response, 75% had SD at their first on treatment scan. Of 5 patients, who were immune checkpoint naïve with ≥ 1 prior TKI treatments, 3 experienced tumor shrinkage, 1 with PR per RECIST 1.1 (unconfirmed). Interrogation of the tumor microenvironment revealed many significant immunological changes post treatment, including increase in total and proliferating NK, CD8+, and CD4+ T cells. There was good correlation between increase in activated CD4+ and CD8+ T cells in peripheral blood with an increase in T cell infiltrates within the tumor tissue. Conclusions: NKTR-214 increased immune infiltration in the tumor and anti-tumor activity in patients who previously progressed on TKIs, with a favorable safety profile. The ability to alter the immune environment and increase PD-1 expression on effectors T cells may improve the effectiveness of anti-PD-1 blockade. A trial combining NKTR-214 and nivolumab is enrolling. Clinical trial information: 02869295.

Phase II randomised discontinuation trial of the MET/VEGF receptor inhibitor cabozantinib in metastatic melanoma

BACKGROUND

A phase II randomised discontinuation trial assessed cabozantinib (XL184), an orally bioavailable inhibitor of tyrosine kinases including VEGF receptors, MET, and AXL, in a cohort of patients with metastatic melanoma.

METHODS

Patients received cabozantinib 100 mg daily during a 12-week lead-in. Patients with stable disease (SD) per Response Evaluation Criteria in Solid Tumours (RECIST) at week 12 were randomised to cabozantinib or placebo. Primary endpoints were objective response rate (ORR) at week 12 and postrandomisation progression-free survival (PFS).

RESULTS

Seventy-seven patients were enroled (62% cutaneous, 30% uveal, and 8% mucosal). At week 12, the ORR was 5%; 39% of patients had SD. During the lead-in phase, reduction in target lesions from baseline was seen in 55% of evaluable patients overall and in 59% of evaluable patients with uveal melanoma. Median PFS after randomisation was 4.1 months with cabozantinib and 2.8 months with placebo (hazard ratio of 0.59; P=0.284). Median PFS from study day 1 was 3.8 months, 6-month PFS was 33%, and median overall survival was 9.4 months. The most common grade 3/4 adverse events were fatigue (14%), hypertension (10%), and abdominal pain (8%). One treatment-related death was reported from peritonitis due to diverticular perforation.

CONCLUSIONS

Cabozantinib has clinical activity in patients with metastatic melanoma, including uveal melanoma. Further clinical investigation is warranted.

Melanoma central nervous system metastases: current approaches, challenges, and opportunities

Melanoma central nervous system metastases are increasing, and the challenges presented by this patient population remain complex. In December 2015, the Melanoma Research Foundation and the Wistar Institute hosted the First Summit on Melanoma Central Nervous System (CNS) Metastases in Philadelphia, Pennsylvania. Here, we provide a review of the current status of the field of melanoma brain metastasis research; identify key challenges and opportunities for improving the outcomes in patients with melanoma brain metastases; and set a framework to optimize future research in this critical area.

PD-1 Blockade with Pembrolizumab in Advanced Merkel-Cell Carcinoma

BACKGROUND

Merkel-cell carcinoma is an aggressive skin cancer that is linked to exposure to ultraviolet light and the Merkel-cell polyomavirus (MCPyV). Advanced Merkel-cell carcinoma often responds to chemotherapy, but responses are transient. Blocking the programmed death 1 (PD-1) immune inhibitory pathway is of interest, because these tumors often express PD-L1, and MCPyV-specific T cells express PD-1.

METHODS

In this multicenter, phase 2, noncontrolled study, we assigned adults with advanced Merkel-cell carcinoma who had received no previous systemic therapy to receive pembrolizumab (anti-PD-1) at a dose of 2 mg per kilogram of body weight every 3 weeks. The primary end point was the objective response rate according to Response Evaluation Criteria in Solid Tumors, version 1.1. Efficacy was correlated with tumor viral status, as assessed by serologic and immunohistochemical testing.

RESULTS

A total of 26 patients received at least one dose of pembrolizumab. The objective response rate among the 25 patients with at least one evaluation during treatment was 56% (95% confidence interval [CI], 35 to 76); 4 patients had a complete response, and 10 had a partial response. With a median follow-up of 33 weeks (range, 7 to 53), relapses occurred in 2 of the 14 patients who had had a response (14%). The response duration ranged from at least 2.2 months to at least 9.7 months. The rate of progression-free survival at 6 months was 67% (95% CI, 49 to 86). A total of 17 of the 26 patients (65%) had virus-positive tumors. The response rate was 62% among patients with MCPyV-positive tumors (10 of 16 patients) and 44% among those with virus-negative tumors (4 of 9 patients). Drug-related grade 3 or 4 adverse events occurred in 15% of the patients.

CONCLUSIONS

In this study, first-line therapy with pembrolizumab in patients with advanced Merkel-cell carcinoma was associated with an objective response rate of 56%. Responses were observed in patients with virus-positive tumors and those with virus-negative tumors. (Funded by the National Cancer Institute and Merck; ClinicalTrials.gov number, NCT02267603.).

MET Inhibition in Clear Cell Renal Cell Carcinoma

Background: Clear cell renal cell carcinoma (ccRCC) is the most lethal form of kidney cancer. Small molecule VEGFR inhibitors are widely used but are not curative and various resistance mechanisms such as activation of the MET pathway have been described. Dual MET/VEGFR2 inhibitors have recently shown clinical benefit but limited preclinical data evaluates their effects in ccRCC.

Methods: An interrogation of the Cancer Genome Atlas (TCGA) dataset was performed to evaluate oncogenic alterations in the MET/VEGFR2 pathway. We evaluated the in vitro effects of Cabozantinib, a dual MET/VEGFR2 inhibitor, using a panel of ccRCC cell lines. Drug effects of cell viability and proliferation, migration, cell scatter, anchorage independent growth, and downstream MET/VEGFR2 signaling pathways were assessed.

Results: Twelve percent of TCGA cases had possible MET/HGF oncogenic alterations with co-occurrence noted (p<0.001). MET/HGF altered cases had worse overall survival (p=0.044). Cabozantinib was a potent inhibitor of MET and VEGFR2 in vitro in our cell line panel. PI3K, MAPK and mTOR pathways were also suppressed by cabozantinib, however the effects on cell viability in vitro were modest. At nanomolar concentrations of cabozantinib, HGF-stimulated migration, invasion, cellular scattering and soft agar colony formation were inhibited.

Conclusions: We provide further preclinical rationale for dual MET/VEGFR2 inhibition in ccRCC. While the MET pathway is implicated in VEGFR resistance, dual inhibitors may have direct anti-tumor effects in a patient subset with evidence of MET pathway involvement. Cabozantinib is a potent dual MET/VEGFR2 inhibitor, significantly inhibits cell migration and invasion in vitro and likely has anti-angiogenic effects similar to other VEGFR tyrosine kinase inhibitors. Future work involving in vivo models will be useful to better define mechanisms of potential anti-tumor activity.

Timing and type of immune checkpoint therapy affect the early radiographic response of melanoma brain metastases to stereotactic radiosurgery

BACKGROUND

Growing evidence suggests that immunotherapy and radiation therapy can be synergistic in the treatment of cancer. This study was performed to determine the effect of the relative timing and type of immune checkpoint therapy on the response of melanoma brain metastases (BrMets) to treatment with stereotactic radiosurgery (SRS).

METHODS

Seventy-five melanoma patients with 566 BrMets were treated with both SRS and immune checkpoint therapy between 2007 and 2015 at a single institution. Immunotherapy and radiosurgery treatment of any single lesion were considered concurrent if SRS was administered within 4 weeks of immunotherapy. The impact of the timing and type of immunotherapy on the lesional response was determined with the Wilcoxon rank-sum test, which was used to compare the median percent lesion volume change 1.5, 3, and 6 months after SRS treatment, with significance determined by P = .0167 according to the Bonferroni correction for multiple comparisons.

RESULTS

Concurrent use of immunotherapy and SRS resulted in a significantly greater median percent reduction in the lesion volume at 1.5 (-63.1% vs -43.2%, P < .0001), 3 (-83.0% vs -52.8%, P < .0001), and 6 months (-94.9% vs -66.2%, P < .0001) in comparison with nonconcurrent therapy. The median percent reduction in the lesion volume was also significantly greater for anti-programmed cell death protein 1 (anti-PD-1) than anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA-4) at 1.5 (-71.1% vs -48.2%, P < .0001), 3 (-89.3% vs -66.2%, P < .0001), and 6 months (-95.1% vs -75.9%, P = .0004).

CONCLUSIONS

The administration of immunotherapy within 4 weeks of SRS results in an improved lesional response of melanoma BrMets in comparison with treatment separated by longer than 4 weeks. Anti-PD-1 therapy also results in a greater lesional response than anti-CTLA-4 after SRS. Cancer 2016;122:3051-3058. © 2016 American Cancer Society.

Pembrolizumab for patients with melanoma or non-small-cell lung cancer and untreated brain metastases: early analysis of a non-randomised, open-label, phase 2 trial

BACKGROUND

Immunotherapy targeting the PD-1 axis has activity in several tumour types. We aimed to establish the activity and safety of the PD-1 inhibitor pembrolizumab in patients with untreated brain metastases from melanoma or non-small-cell lung cancer (NSCLC).

METHODS

In this non-randomised, open-label, phase 2 trial, we enrolled patients aged 18 years or older with melanoma or NSCLC with untreated brain metastases from the Yale Cancer Center. Patients had at least one untreated or progressive brain metastasis between 5 and 20 mm in diameter without associated neurological symptoms or the need for corticosteroids. Patients with NSCLC had tumour tissue positive for PD-L1 expression; this was not required for patients with melanoma. Patients were given 10 mg/kg pembrolizumab every 2 weeks until progression. The primary endpoint was brain metastasis response assessed in all treated patients. The trial is ongoing and here we present an early analysis. The study is registered with ClinicalTrials.gov, number NCT02085070.

FINDINGS

Between March 31, 2014, and May 31, 2015, we screened 52 patients with untreated or progressive brain metastases (18 with melanoma, 34 with NSCLC), and enrolled 36 (18 with melanoma, 18 with NSCLC). A brain metastasis response was achieved in four (22%; 95% CI 7-48) of 18 patients with melanoma and six (33%; 14-59) of 18 patients with NSCLC. Responses were durable, with all but one patient with NSCLC who responded showing an ongoing response at the time of data analysis on June 30, 2015. Treatment-related serious and grade 3-4 adverse events were grade 3 elevated aminotransferases (n=1 [6%]) in the melanoma cohort, and grade 3 colitis (n=1 [6%]), grade 3 pneumonitis (n=1 [6%]), grade 3 fatigue (n=1 [6%]), grade 4 hyperkalemia (n=1 [6%]), and grade 2 acute kidney injury (n=1 [6%]) in the NSCLC cohort. Clinically significant neurological adverse events included transient grade 3 cognitive dysfunction and grade 1-2 seizures (n=3 [17%]) in the melanoma cohort.

INTERPRETATION

Pembrolizumab shows activity in brain metastases in patients with melanoma or NSCLC with an acceptable safety profile, which suggests that there might be a role for systemic immunotherapy in patients with untreated or progressive brain metastases.

FUNDING

Merck and the Yale Cancer Center.

Possible Interaction of Anti-PD-1 Therapy with the Effects of Radiosurgery on Brain Metastases

Delayed radiation-induced vasculitic leukoencephalopathy related to stereotactic radiosurgery (SRS) of brain metastases has been reported to manifest clinically 9 to 18 months after treatment. Immune-modulating therapies have been introduced to treatment regimens for malignancies with metastatic predilection to the brain. The interaction of these systemic therapies with other modalities of treatment for brain metastases, namely, SRS, has not been fully characterized. We report two patients with metastatic malignancies to the brain who received SRS followed by immunotherapy with monoclonal antibodies (mAb) to programmed death 1 (PD-1). Both patients appeared to have early clinical and radiologic progression of their treated lesions, which was highly suspicious for tumor progression. Both patients underwent surgical resection of their lesions and the material was submitted for histopathologic examination. Pathologic examination in both cases showed predominantly radiation-induced changes characterized by reactive astrocytosis and vascular wall infiltration by T lymphocytes. The accelerated response to SRS in these two patients was temporally related to the initiation of immunotherapy. We propose a possible biologic interaction between SRS and the PD-1 mAbs. Additionally, awareness of this potential occurrence is critical for accurate interpretation and proper management of clinical and radiologic findings in these patients. Cancer Immunol Res; 4(6); 481-7. ©2016 AACR.