First-in-human Phase I Trial of TPST-1120, an Inhibitor of PPARα, as Monotherapy or in Combination with Nivolumab, in Patients with Advanced Solid Tumors.

PURPOSE: TPST-1120 is a first-in-class oral inhibitor of peroxisome proliferator-activated receptor α (PPARα), a fatty acid ligand-activated transcription factor that regulates genes involved in fatty acid oxidation, angiogenesis, and inflammation, and is a novel target for cancer therapy. TPST-1120 displayed antitumor activity in xenograft models and synergistic tumor reduction in syngeneic tumor models when combined with anti-PD-1 agents. EXPERIMENTAL DESIGN: This phase I, open-label, dose-escalation study (NCT03829436) evaluated TPST-1120 as monotherapy in patients with advanced solid tumors and in combination with nivolumab in patients with renal cell carcinoma (RCC), cholangiocarcinoma (CCA), or hepatocellular carcinoma. Objectives included evaluation of safety, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity (RECIST v1.1). RESULTS: A total of 39 patients enrolled with 38 treated (20 monotherapy, 18 combination; median 3 prior lines of therapy). The most common treatment-related adverse events (TRAE) were grade 1-2 nausea, fatigue, and diarrhea. No grade 4-5 TRAEs or dose-limiting toxicities were reported. In the monotherapy group, 53% (10/19) of evaluable patients had a best objective response of stable disease. In the combination group, 3 patients had partial responses, for an objective response rate of 20% (3/15) across all doses and 30% (3/10) at TPST-1120 ≥400 mg twice daily. Responses occurred in 2 patients with RCC, both of whom had previously progressed on anti-PD-1 therapy, and 1 patient with late-line CCA. CONCLUSIONS: TPST-1120 was well tolerated as monotherapy and in combination with nivolumab and the combination showed preliminary evidence of clinical activity in PD-1 inhibitor refractory and immune compromised cancers. SIGNIFICANCE: TPST-1120 is a first-in-class oral inhibitor of PPARα, whose roles in metabolic and immune regulation are implicated in tumor proliferation/survival and inhibition of anticancer immunity. This first-in-human study of TPST-1120 alone and in combination with nivolumab supports proof-of-concept of PPARα inhibition as a target of therapeutic intervention in solid tumors.

The application of autologous cancer immunotherapies in the age of memory-NK cells.

Cellular immunotherapy has revolutionized the oncology field, yielding improved results against hematological and solid malignancies. NK cells have become an attractive alternative due to their capacity to activate upon recognition of "stress" or "danger" signals independently of Major Histocompatibility Complex (MHC) engagement, thus making tumor cells a perfect target for NK cell-mediated cancer immunotherapy even as an allogeneic solution. While this allogeneic use is currently favored, the existence of a characterized memory function for NK cells ("memory-like" NK cells) advocates for an autologous approach, that would benefit from the allogeneic setting discoveries, but with added persistence and specificity. Still, both approaches struggle to exert a sustained and high anticancer effect in-vivo due to the immunosuppressive tumor micro-environment and the logistical challenges of cGMP production or clinical deployment. Novel approaches focused on the quality enhancement and the consistent large-scale production of highly activated therapeutic memory-like NK cells have yielded encouraging but still unconclusive results. This review provides an overview of NK biology as it relates to cancer immunotherapy and the challenge presented by solid tumors for therapeutic NKs. After contrasting the autologous and allogeneic NK approaches for solid cancer immunotherapy, this work will present the current scientific focus for the production of highly persistent and cytotoxic memory-like NK cells as well as the current issues with production methods as they apply to stress-sensitive immune cells. In conclusion, autologous NK cells for cancer immunotherapy appears to be a prime alternative for front line therapeutics but to be successful, it will be critical to establish comprehensives infrastructures allowing the production of extremely potent NK cells while constraining costs of production.

Brief Report: Safety and Antitumor Activity of Durvalumab Plus Tremelimumab in Programmed Cell Death-(Ligand)1-Monotherapy Pretreated, Advanced NSCLC: Results From a Phase 1b Clinical Trial.

INTRODUCTION: Although first-line immunotherapy approaches are standard, in patients with non-small cell lung cancer (NSCLC) previously treated with programmed cell death protein-1 or programmed death-(ligand)1 (PD-[L]1) inhibitors, the activity of combined CTLA-4 plus PD-(L)1 inhibition is unknown. This phase 1b study evaluated the safety and efficacy of durvalumab plus tremelimumab in adults with advanced NSCLC who received anti-PD-(L)1 monotherapy as their most recent line of therapy. METHODS: Patients with PD-(L)1-relapsed or refractory NSCLC were enrolled between October 25, 2013, and September 17, 2019. Durvalumab 20 mg/kg plus tremelimumab 1 mg/kg was administered intravenously every 4 weeks for four doses, followed by up to nine doses of durvalumab monotherapy every 4 weeks for up to 12 months of treatment or disease progression. Primary end points included safety and objective response rate (ORR) on the basis of Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1) per blinded independent central review; secondary end points were ORR on the basis of RECIST v1.1 per investigator; duration of response, disease control, and progression-free survival on the basis of RECIST v1.1 per blinded independent central review and investigator; and overall survival. CLINICALTRIALS: gov identifier: NCT02000947. RESULTS: PD-(L)1-refractory (n = 38) and PD-(L)1-relapsed (n = 40) patients were treated. The most common treatment-related adverse events were fatigue (26.3%, PD-(L)1-refractory patients) and diarrhea (27.5%, PD-(L)1-relapsed patients). Grade 3 to 4 treatment-related adverse events occurred in 22 patients. Median follow-up duration was 43.6 months for PD-(L)1-refractory patients and 41.2 months for PD-(L)1-relapsed patients. The ORR was 5.3% for PD-(L)1-refractory patients (one complete response, one partial response) and 0% for PD-(L)1-relapsed patients. CONCLUSIONS: Durvalumab plus tremelimumab had a manageable safety profile, but the combination did not have efficacy after PD-(L)1 treatment failure.

Survival, Durable Tumor Remission, and Long-Term Safety in Patients With Advanced Melanoma Receiving Nivolumab.

PURPOSE: Programmed cell death 1 (PD-1) is an inhibitory receptor expressed by activated T cells that downmodulates effector functions and limits the generation of immune memory. PD-1 blockade can mediate tumor regression in a substantial proportion of patients with melanoma, but it is not known whether this is associated with extended survival or maintenance of response after treatment is discontinued. PATIENTS AND METHODS: Patients with advanced melanoma (N = 107) enrolled between 2008 and 2012 received intravenous nivolumab in an outpatient setting every 2 weeks for up to 96 weeks and were observed for overall survival, long-term safety, and response duration after treatment discontinuation. RESULTS: Median overall survival in nivolumab-treated patients (62% with two to five prior systemic therapies) was 16.8 months, and 1- and 2-year survival rates were 62% and 43%, respectively. Among 33 patients with objective tumor regressions (31%), the Kaplan-Meier estimated median response duration was 2 years. Seventeen patients discontinued therapy for reasons other than disease progression, and 12 (71%) of 17 maintained responses off-therapy for at least 16 weeks (range, 16 to 56+ weeks). Objective response and toxicity rates were similar to those reported previously; in an extended analysis of all 306 patients treated on this trial (including those with other cancer types), exposure-adjusted toxicity rates were not cumulative. CONCLUSION: Overall survival following nivolumab treatment in patients with advanced treatment-refractory melanoma compares favorably with that in literature studies of similar patient populations. Responses were durable and persisted after drug discontinuation. Long-term safety was acceptable. Ongoing randomized clinical trials will further assess the impact of nivolumab therapy on overall survival in patients with metastatic melanoma.

Phase I Study of Single-Agent Anti-Programmed Death-1 (MDX-1106) in Refractory Solid Tumors: Safety, Clinical Activity, Pharmacodynamics, and Immunologic Correlates.

PURPOSE: Programmed death-1 (PD-1), an inhibitory receptor expressed on activated T cells, may suppress antitumor immunity. This phase I study sought to determine the safety and tolerability of anti-PD-1 blockade in patients with treatment-refractory solid tumors and to preliminarily assess antitumor activity, pharmacodynamics, and immunologic correlates. PATIENTS AND METHODS: Thirty-nine patients with advanced metastatic melanoma, colorectal cancer (CRC), castrate-resistant prostate cancer, non-small-cell lung cancer (NSCLC), or renal cell carcinoma (RCC) received a single intravenous infusion of anti-PD-1 (MDX-1106) in dose-escalating six-patient cohorts at 0.3, 1, 3, or 10 mg/kg, followed by a 15-patient expansion cohort at 10 mg/kg. Patients with evidence of clinical benefit at 3 months were eligible for repeated therapy. RESULTS: Anti-PD-1 was well tolerated: one serious adverse event, inflammatory colitis, was observed in a patient with melanoma who received five doses at 1 mg/kg. One durable complete response (CRC) and two partial responses (PRs; melanoma, RCC) were seen. Two additional patients (melanoma, NSCLC) had significant lesional tumor regressions not meeting PR criteria. The serum half-life of anti-PD-1 was 12 to 20 days. However, pharmacodynamics indicated a sustained mean occupancy of > 70% of PD-1 molecules on circulating T cells ≥ 2 months following infusion, regardless of dose. In nine patients examined, tumor cell surface B7-H1 expression appeared to correlate with the likelihood of response to treatment. CONCLUSION: Blocking the PD-1 immune checkpoint with intermittent antibody dosing is well tolerated and associated with evidence of antitumor activity. Exploration of alternative dosing regimens and combinatorial therapies with vaccines, targeted therapies, and/or other checkpoint inhibitors is warranted.

Phase 1/2 study of epacadostat in combination with durvalumab in patients with metastatic solid tumors.

BACKGROUND: Targeting programmed cell death protein 1 (PD-1) and indoleamine 2,3-dioxygenase (IDO1) pathways is an appealing option for cancer treatment. METHODS: The open-label, phase 1/2 ECHO-203 study evaluated the safety, tolerability, and efficacy of the IDO1 inhibitor epacadostat in combination with durvalumab, a human anti-PD-L1 monoclonal antibody in adult patients with advanced solid tumors. RESULTS: The most common treatment-related adverse events were fatigue (30.7%), nausea (21.0%), decreased appetite (13.1%), pruritus (12.5%), maculopapular rash (10.8%), and diarrhea (10.2%). Objective response rate (ORR) in the overall phase 2 population was 12.0%. Higher ORR was observed in immune checkpoint inhibitor (CPI)-naïve patients (16.1%) compared with patients who had received previous CPI (4.1%). Epacadostat pharmacodynamics were evaluated by comparing baseline kynurenine levels with those on therapy at various time points. Only the 300-mg epacadostat dose showed evidence of kynurenine modulation, albeit unsustained. CONCLUSIONS: Epacadostat plus durvalumab was generally well tolerated in patients with advanced solid tumors. ORR was low, and evaluation of kynurenine concentration from baseline to cycle 2, day 1, and cycle 5, day 1, suggested >300 mg epacadostat twice daily is needed to ensure sufficient drug effect. CLINICAL TRIAL INFORMATION: A study of epacadostat (INCB024360) in combination with durvalumab (MEDI4736) in subjects with selected advanced solid tumors (ECHO-203) (NCT02318277).

Epacadostat Plus Pembrolizumab and Chemotherapy for Advanced Solid Tumors: Results from the Phase I/II ECHO-207/KEYNOTE-723 Study.

BACKGROUND: Epacadostat, an oral, selective inhibitor of IDO1, has shown activity when administered with pembrolizumab. We evaluated the addition of chemotherapy to epacadostat and pembrolizumab in patients with advanced or metastatic solid tumors. One proposed mechanism of resistance to PD-1 checkpoint inhibition is through immunosuppression mediated by L-kynurenine. IDO1, indoleamine-2,3-dioxygenase 1 is the rate-limiting enzyme catalyzing the conversion of L-tryptophan to L-kynurenine. If IDO1 is a mechanism of tumor escape from checkpoint inhibition, then addition of an IDO1 inhibitor with a PD-1 checkpoint inhibitor could enable tumor response to immunotherapy. METHODS: Patients received one of 7 tumor-appropriate chemotherapy regimens. Pembrolizumab 200 mg was infused intravenously every 3 weeks. Epacadostat 100 mg was administered orally twice daily. The primary objectives of phase I were determining safety/tolerability and defining the maximum tolerated or pharmacologically active dose of epacadostat. Phase II of the study was designed to enroll efficacy-expansion cohorts and to assess changes in the tumor and tumor microenvironment via mandatory-biopsy cohorts. RESULTS: A total of 70 patients were enrolled. Twelve patients were enrolled in the phase II mandatory-biopsy cohorts. Due to early study closure, efficacy expansion did not enroll. Grades 3 and 4 treatment-emergent adverse events (TEAEs) occurred in 78.6% of patients. Neutropenia and disease progression were the only grades 3 and 4 TEAEs reported in ≥10.0% of patients. One treatment-related death was reported. The ORR was 31.4% across all treatment groups. CONCLUSION: The combination of epacadostat 100 mg bid with pembrolizumab and chemotherapy had an acceptable safety profile. This regimen showed antitumor activity across multiple types of advanced or metastatic solid tumors (ClinicalTrials.gov Identifier: NCT03085914).

Safety and Tolerability of MEDI0562, an OX40 Agonist mAb, in Combination with Durvalumab or Tremelimumab in Adult Patients with Advanced Solid Tumors.

PURPOSE: Combination therapies targeting immunologic checkpoints have shown promise in treating multiple tumor types. We report safety and tolerability of MEDI0562, a humanized IgG1K OX40 mAb, in combination with durvalumab (anti-PD-L1), or tremelimumab (anti-CTLA-4), in adult patients with previously treated advanced solid tumors. PATIENTS AND METHODS: In this phase I, multicenter, open-label study, patients received escalating doses of MEDI0562 (2.25, 7.5, or 22.5 mg) every 2 weeks in combination with durvalumab (1,500 mg) or tremelimumab (75 or 225 mg) every 4 weeks, intravenously, until unacceptable toxicity or progressive disease. Tumor assessments were performed every 8 weeks. The primary objective was to evaluate safety and tolerability. RESULTS: Among the 27 and 31 patients who received MEDI0562 + durvalumab or MEDI0562 + tremelimumab, 74.1% and 67.7% reported a treatment-related adverse event (AE), and 22.2% and 19.4% experienced a treatment-emergent AE that led to discontinuation, respectively. The MTD of MEDI0562 + durvalumab was 7.5 mg MEDI0562 + 1,500 mg durvalumab; the maximum administered dose of MEDI0562 + tremelimumab was 22.5 mg MEDI0562 + 225 mg tremelimumab. Three patients in the MEDI0562 + durvalumab arm had a partial response. The mean percentage of Ki67+CD4+ and Ki67+CD8+ memory T cells increased by >100% following the first dose of MEDI0562 + durvalumab or tremelimumab in all dose cohorts. A decrease in OX40+FOXP3 regulatory T cells was observed in a subset of patients with available paired biopsies. CONCLUSIONS: Following dose escalation, moderate toxicity was observed in both treatment arms, with no clear efficacy signals demonstrated.

Exploring the safety, effect on the tumor microenvironment, and efficacy of itacitinib in combination with epacadostat or parsaclisib in advanced solid tumors: a phase I study.

BACKGROUND: This phase I multicenter study was designed to evaluate the safety, tolerability, efficacy, and translational effects on the tumor microenvironment of itacitinib (Janus-associated kinase 1 (JAK1) inhibitor) in combination with epacadostat (indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor) or parsaclisib (phosphatidylinositol 3-kinase δ (PI3Kδ) inhibitor). METHODS: Patients with advanced or metastatic solid tumors were enrolled and received itacitinib (100-400 mg once a day) plus epacadostat (50-300 mg two times per day; group A), or itacitinib (100-400 mg once a day) plus parsaclisib or parsaclisib monotherapy (0.3-10 mg once a day; group B). RESULTS: A total of 142 patients were enrolled in the study. The maximum tolerated dose was not reached for either the combination of itacitinib plus epacadostat (n=47) or itacitinib plus parsaclisib (n=90). One dose-limiting toxicity of serious, grade 3 aseptic meningitis was reported in a patient receiving itacitinib 300 mg once a day plus parsaclisib 10 mg once a day, which resolved when the study drugs were withdrawn. The most common treatment-related adverse events among patients treated with itacitinib plus epacadostat included fatigue, nausea, pyrexia, and vomiting, and for patients treated with itacitinib plus parsaclisib were fatigue, pyrexia, and diarrhea. In the itacitinib plus epacadostat group, no patient had an objective response. Among patients receiving itacitinib 100 mg once a day plus parsaclisib 0.3 mg once a day, three achieved partial response for an objective response rate (95% CI) of 7.1% (1.50 to 19.48). Treatment with itacitinib plus epacadostat demonstrated some increase in tumor CD8+ T cell infiltration and minor changes in six plasma proteins, whereas treatment with itacitinib plus high-dose parsaclisib resulted in downregulation of 20 plasma proteins mostly involved in immune cell function, with no observed change in intratumoral CD8+ T cell infiltration. CONCLUSION: Adverse events with JAK1 inhibition combined with either IDO1 or PI3Kδ inhibition were manageable, but the combinations demonstrated limited clinical activity or enhancement of immune activation in the tumor microenvironment. TRIAL REGISTRATION NUMBER: NCT02559492.

First-in-Human Phase I Study of ABBV-085, an Antibody-Drug Conjugate Targeting LRRC15, in Sarcomas and Other Advanced Solid Tumors.

PURPOSE: Leucine-rich repeat containing 15 (LRRC15) is expressed on stromal fibroblasts in the tumor microenvironment of multiple solid tumor types and may represent an interesting target for therapy, particularly in patients with sarcomas where LRRC15 is also expressed by malignant cells. ABBV-085 is a monomethyl auristatin-E antibody-drug conjugate that targets LRRC15 and showed antineoplastic efficacy in preclinical experiments. Herein, we report findings of ABBV-085 monotherapy or combination therapy in adult patients with sarcomas and other advanced solid tumors. PATIENTS AND METHODS: This first-in-human phase I study (NCT02565758) assessed ABBV-085 safety, pharmacokinetics/pharmacodynamics, and preliminary antitumor activity. The study consisted of two parts: dose escalation and dose expansion. ABBV-085 was administered by intravenous infusion at 0.3 to 6.0 mg/kg every 14 days. RESULTS: In total, 85 patients were enrolled; 45 patients received the recommended expansion dose of 3.6 mg/kg ABBV-085 monotherapy, including 10 with osteosarcoma and 10 with undifferentiated pleomorphic sarcoma (UPS). Most common treatment-related adverse events were fatigue, nausea, and decreased appetite. The overall response rate for patients with osteosarcoma/UPS treated at 3.6 mg/kg was 20%, including four confirmed partial responses. No monotherapy responses were observed for other advanced cancers treated at 3.6 mg/kg. One patient treated with ABBV-085 plus gemcitabine achieved partial response. CONCLUSIONS: ABBV-085 appeared safe and tolerable at a dose of 3.6 mg/kg every 14 days, with preliminary antitumor activity noted in patients with osteosarcoma and UPS. Given the high unmet need in these orphan malignancies, further investigation into targeting LRRC15 in these sarcomas may be warranted.

Safety and Clinical Activity of Atezolizumab in Patients with Metastatic Castration-Resistant Prostate Cancer: A Phase I Study.

PURPOSE: Atezolizumab [anti-programmed death-ligand 1 (anti-PD-L1)] is well tolerated and efficacious in multiple cancers, but has not been previously evaluated in metastatic castration-resistant prostate cancer (mCRPC). This study examined the safety, efficacy, and biomarkers of atezolizumab monotherapy for mCRPC. PATIENTS AND METHODS: This phase Ia, open-label, dose-escalation and dose-expansion study (PCD4989g) enrolled patients with mCRPC who had progressed on sipuleucel-T or enzalutamide. Atezolizumab was given intravenously every 3 weeks until confirmed disease progression or loss of clinical benefit. Prespecified endpoints included safety, efficacy, biomarker analyses, and radiographic assessments. RESULTS: All 35 evaluable patients [median age, 68 years (range, 45-83 years)] received atezolizumab after ≥1 prior line of therapy; 62.9% of patients had received ≥3 prior lines. Treatment-related adverse events occurred in 21 patients (60.0%), with no deaths. One patient had a confirmed partial response (PR) per RECIST 1.1, and 1 patient had a PR per immune-related response criteria. The confirmed 50% PSA response rate was 8.6% (3 patients). Median overall survival (OS) was 14.7 months [95% confidence interval (CI): 5.9-not evaluable], with a 1-year OS rate of 52.3% (95% CI: 34-70); 2-year OS was 35.9% (95% CI: 13-59). Median follow-up was 13.0 months (range, 1.2-28.1 months). Biomarker analyses showed that atezolizumab activated immune responses; however, a composite biomarker failed to reveal consistent correlations with efficacy. CONCLUSIONS: Atezolizumab was generally well tolerated in patients with mCRPC, with a safety profile consistent with other tumor types. In heavily pretreated patients, atezolizumab monotherapy demonstrated evidence of disease control; however, its limited efficacy suggests a combination approach may be needed.

Model Informed Dosing Regimen and Phase I Results of the Anti-PD-1 Antibody Budigalimab (ABBV-181).

Budigalimab is a humanized, recombinant, Fc mutated IgG1 monoclonal antibody targeting programmed cell death 1 (PD-1) receptor, currently in phase I clinical trials. The safety, efficacy, pharmacokinetics (PKs), pharmacodynamics (PDs), and budigalimab dose selection from monotherapy dose escalation and multihistology expansion cohorts were evaluated in patients with previously treated advanced solid tumors who received budigalimab at 1, 3, or 10 mg/kg intravenously every 2 weeks (Q2W) in dose escalation, including Japanese patients that received 3 and 10 mg/kg Q2W. PK modeling and PK/PD assessments informed the dosing regimen in expansion phase using data from body-weight-based dosing in the escalation phase, based on which patients in the multihistology expansion cohort received flat doses of 250 mg Q2W or 500 mg every four weeks (Q4W). Immune-related adverse events (AEs) were reported in 11 of 59 patients (18.6%), of which 1 of 59 (1.7%) was considered grade ≥ 3 and the safety profile of budigalimab was consistent with other PD-1 targeting agents. No treatment-related grade 5 AEs were reported. Four responses per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 were reported in the dose escalation cohort and none in the multihistology expansion cohort. PK of budigalimab was approximately dose proportional and sustained > 99% peripheral PD-1 receptor saturation was observed by 2 hours postdosing, across doses. PK/PD and safety profiles were comparable between Japanese and Western patients, and exposure-safety analyses did not indicate any trends. Observed PK and PD-1 receptor saturation were consistent with model predictions for flat doses and less frequent regimens, validating the early application of PK modeling and PK/PD assessments to inform the recommended dose and regimen, following dose escalation.

Safety and Clinical Activity of MEDI0562, a Humanized OX40 Agonist Monoclonal Antibody, in Adult Patients with Advanced Solid Tumors.

PURPOSE: Immune checkpoint blockade has demonstrated clinical benefits across multiple solid tumor types; however, resistance and relapse often occur. New immunomodulatory targets, which are highly expressed in activated immune cells, are needed. MEDI0562, an agonistic humanized mAb, specifically binds to the costimulatory molecule OX40. This first-in-human study evaluated MEDI0562 in adults with advanced solid tumors. PATIENTS AND METHODS: In this phase I, multicenter, open-label, single-arm, dose-escalation (3+3 design) study, patients received 0.03, 0.1, 0.3, 1.0, 3.0, or 10 mg/kg MEDI0562 through intravenous infusion every 2 weeks, until confirmed disease progression or unacceptable toxicity. The primary objective evaluated safety and tolerability. Secondary endpoints included antitumor activity, pharmacokinetics, immunogenicity, and pharmacodynamics. RESULTS: In total, 55 patients received ≥1 dose of MEDI0562 and were included in the analysis. The most common tumor type was squamous cell carcinoma of the head and neck (47%). Median duration of treatment was 10 weeks (range, 2-48 weeks). Treatment-related adverse events (TRAEs) occurred in 67% of patients, most commonly fatigue (31%) and infusion-related reactions (14%). Grade 3 TRAEs occurred in 14% of patients with no apparent dose relationship; no TRAEs resulted in death. Two patients had immune-related partial responses per protocol and 44% had stable disease. MEDI0562 induced increased Ki67+ CD4+ and CD8+ memory T-cell proliferation in the periphery and decreased intratumoral OX40+ FOXP3+ cells. CONCLUSIONS: MEDI0562 was safely administered at doses up to 10 mg/kg in heavily pretreated patients. On-target pharmacodynamic effects were suggested in this setting. Further evaluation with immune checkpoint inhibitors is ongoing.

Final overall survival and safety update for durvalumab in third- or later-line advanced NSCLC: The phase II ATLANTIC study.

INTRODUCTION: In the phase II ATLANTIC study, durvalumab provided durable responses with acceptable tolerability in heavily pretreated patients with advanced NSCLC, across three independent patient cohorts defined by EGFR/ALK status and tumour PD-L1 expression. Preliminary overall survival (OS) data were encouraging. We now report final OS and updated safety data. METHODS: Patients with advanced NSCLC with disease progression following ≥2 previous systemic regimens received durvalumab 10 mg/kg every 2 weeks. The primary endpoint was objective response rate among patients with increased PD-L1 expression (defined as ≥25 % or ≥90 % of tumour cells [TCs], cohort-dependent). Secondary endpoints included OS and safety. RESULTS: 444 patients received durvalumab: 111 in Cohort 1 (EGFR+/ALK+), 265 in Cohort 2 (EGFR-/ALK-), and 68 in Cohort 3 (EGFR-/ALK-; TC ≥ 90 %). Median (95 % CI) OS was 13.3 months (6.3-24.5) in patients with EGFR+/ALK+ NSCLC with TC ≥ 25 %, 10.9 months (8.6-13.6) in patients with EGFR-/ALK- NSCLC with TC ≥ 25 %, and 13.2 months (5.9-not reached) in patients with EGFR-/ALK- NSCLC with TC ≥ 90 %. Median (95 % CI) OS was slightly shorter in patients with TC < 25 % (9.9 months [4.2-13.3] in patients with EGFR+/ALK+ NSCLC and 9.3 months [5.9-10.8] in those with EGFR-/ALK- NSCLC). Treatment-related adverse events of special interest occurred with similar incidences as reported previously. CONCLUSIONS: After additional follow-up, final OS data remain encouraging across all cohorts, further supporting the clinical activity of durvalumab in patients with heavily pretreated advanced NSCLC, including those with EGFR+/ALK+ tumours. There were no new safety signals.

Safety and Clinical Activity of Atezolizumab Plus Bevacizumab in Patients with Ovarian Cancer: A Phase Ib Study.

PURPOSE: Atezolizumab has shown antitumor activity in patients with ovarian cancer. Dual blockade of programmed death-ligand 1 (PD-L1) and VEGF enhances anticancer immunity and augments antitumor activity in several cancers. The safety and efficacy of atezolizumab plus bevacizumab were evaluated in patients with ovarian cancer. PATIENTS AND METHODS: In this open-label, multicenter phase Ib study, patients with platinum-resistant ovarian cancer received intravenous atezolizumab (1,200 mg) and bevacizumab (15 mg/kg) once every 3 weeks. The primary endpoint was safety; secondary endpoints included overall response rate (ORR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Exploratory biomarkers were also evaluated. RESULTS: Twenty patients received treatment. Treatment-related adverse events occurred in 19 patients (95%); seven (35%) had grade 3/4 events. No grade 5 events occurred. The safety profile of atezolizumab plus bevacizumab was consistent with those of the individual agents. Two patients (10%) discontinued treatment because of pneumonitis and small bowel obstruction. Three patients had partial responses of 11.3-18.9 months' duration; the ORR was 15%. Eight patients (40%) had stable disease, hence the disease control rate was 55%. The median DOR was not reached (95% confidence interval, 11.3-not reached). Median PFS was 4.9 months (range, 1.2-20.2); median OS was 10.2 months (range, 1.2-26.6). No association was seen between treatment response and PD-L1 expression, tumor histology, or number of prior therapies. CONCLUSIONS: Atezolizumab plus bevacizumab led to durable responses and/or disease stabilization in some patients with platinum-resistant ovarian cancer; the safety profiles were consistent with those of each agent.

Adenosine 2A Receptor Blockade as an Immunotherapy for Treatment-Refractory Renal Cell Cancer.

Adenosine mediates immunosuppression within the tumor microenvironment through triggering adenosine 2A receptors (A2AR) on immune cells. To determine whether this pathway could be targeted as an immunotherapy, we performed a phase I clinical trial with a small-molecule A2AR antagonist. We find that this molecule can safely block adenosine signaling in vivo. In a cohort of 68 patients with renal cell cancer (RCC), we also observe clinical responses alone and in combination with an anti-PD-L1 antibody, including subjects who had progressed on PD-1/PD-L1 inhibitors. Durable clinical benefit is associated with increased recruitment of CD8+ T cells into the tumor. Treatment can also broaden the circulating T-cell repertoire. Clinical responses are associated with an adenosine-regulated gene-expression signature in pretreatment tumor biopsies. A2AR signaling, therefore, represents a targetable immune checkpoint distinct from PD-1/PD-L1 that restricts antitumor immunity. SIGNIFICANCE: This first-in-human study of an A2AR antagonist for cancer treatment establishes the safety and feasibility of targeting this pathway by demonstrating antitumor activity with single-agent and anti-PD-L1 combination therapy in patients with refractory RCC. Responding patients possess an adenosine-regulated gene-expression signature in pretreatment tumor biopsies.See related commentary by Sitkovsky, p. 16.This article is highlighted in the In This Issue feature, p. 1.

Safety, Clinical Activity, and Biological Correlates of Response in Patients with Metastatic Melanoma: Results from a Phase I Trial of Atezolizumab.

PURPOSE: Atezolizumab [anti-programmed death-ligand 1 (PD-L1)] selectively targets PD-L1 to block its interaction with receptors programmed death 1 and B7.1, thereby reinvigorating antitumor T-cell activity. We evaluated the long-term safety and activity of atezolizumab, along with biological correlates of clinical activity endpoints, in a cohort of patients with melanoma in an ongoing phase Ia study (NCT01375842). PATIENTS AND METHODS: Patients with unresectable or metastatic melanoma were enrolled to receive atezolizumab 0.1 to 20 mg/kg or ≥10 mg/kg every 3 weeks. Primary study objectives were safety and tolerability. Secondary objectives included investigator-assessed efficacy measures; pharmacodynamic and predictive biomarkers of antitumor activity were explored. RESULTS: Forty-five patients were enrolled and were evaluable for safety. Most treatment-related adverse events (AE) were grade 1/2 (60%). Fatigue (44%), pruritus (20%), pyrexia (18%), and rash (18%) were the most common treatment-related AEs of any grade. No treatment-related deaths occurred. Overall response rate was 30% among 43 efficacy- evaluable patients, with a median duration of response of 62 months [95% CI, 35-not estimable (NE)]. Clinically meaningful long-term survival was observed, with a median overall survival of 23 months (95% CI, 9-66). Baseline biomarkers of tumor immunity [PD-L1 expression on immune cells, T effector (Teff), and antigen presentation gene signatures) and tumor mutational burden (TMB) were associated with improved response, progression-free survival, and overall survival. CONCLUSIONS: Atezolizumab was well tolerated, with durable responses and survival in patients with melanoma. PD-L1 expression, TMB, and Teff signatures may indicate improved benefit with atezolizumab in these patients.

Five-Year Survival and Correlates Among Patients With Advanced Melanoma, Renal Cell Carcinoma, or Non-Small Cell Lung Cancer Treated With Nivolumab.

IMPORTANCE: Nivolumab, a monoclonal antibody that inhibits programmed cell death 1, is approved by the US Food and Drug Administration for treating advanced melanoma, renal cell carcinoma (RCC), non-small cell lung cancer (NSCLC), and other malignancies. Data on long-term survival among patients receiving nivolumab are limited. OBJECTIVES: To analyze long-term overall survival (OS) among patients receiving nivolumab and identify clinical and laboratory measures associated with tumor regression and OS. DESIGN, SETTING, AND PARTICIPANTS: This was a secondary analysis of the phase 1 CA209-003 trial (with expansion cohorts), which was conducted at 13 US medical centers and included 270 patients with advanced melanoma, RCC, or NSCLC who received nivolumab and were enrolled between October 30, 2008, and December 28, 2011. The analyses were either specified in the original protocol or included in subsequent protocol amendments that were implemented between 2008 and 2012. Statistical analysis was performed from October 30, 2008, to November 11, 2016. INTERVENTION: In the CA209-003 trial, patients received nivolumab (0.1-10.0 mg/kg) every 2 weeks in 8-week cycles for up to 96 weeks, unless they developed progressive disease, achieved a complete response, experienced unacceptable toxic effects, or withdrew consent. MAIN OUTCOMES AND MEASURES: Safety and activity of nivolumab; OS was a post hoc end point with a minimum follow-up of 58.3 months. RESULTS: Of 270 patients included in this analysis, 107 (39.6%) had melanoma (72 [67.3%] male; median age, 61 [range, 29-85] years), 34 (12.6%) had RCC (26 [76.5%] male; median age, 58 [range, 35-74] years), and 129 (47.8%) had NSCLC (79 [61.2%] male; median age, 65 [range, 38-85] years). Overall survival curves showed estimated 5-year rates of 34.2% among patients with melanoma, 27.7% among patients with RCC, and 15.6% among patients with NSCLC. In a multivariable analysis, the presence of liver (odds ratio [OR], 0.31; 95% CI, 0.12-0.83; P = .02) or bone metastases (OR, 0.31; 95% CI, 0.10-0.93; P = .04) was independently associated with reduced likelihood of survival at 5 years, whereas an Eastern Cooperative Oncology Group performance status of 0 (OR, 2.74; 95% CI, 1.43-5.27; P = .003) was independently associated with an increased likelihood of 5-year survival. Overall survival was significantly longer among patients with treatment-related AEs of any grade (median, 19.8 months; 95% CI, 13.8-26.9 months) or grade 3 or more (median, 20.3 months; 95% CI, 12.5-44.9 months) compared with those without treatment-related AEs (median, 5.8 months; 95% CI, 4.6-7.8 months) (P < .001 for both comparisons based on hazard ratios). CONCLUSIONS AND RELEVANCE: Nivolumab treatment was associated with long-term survival in a subset of heavily pretreated patients with advanced melanoma, RCC, or NSCLC. Characterizing factors associated with long-term survival may inform treatment approaches and strategies for future clinical trial development. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00730639.

Efficacy and Safety of Avelumab Treatment in Patients With Advanced Unresectable Mesothelioma: Phase 1b Results From the JAVELIN Solid Tumor Trial.

Importance: Patients with malignant mesothelioma whose disease has progressed after platinum and pemetrexed treatment have limited options. Anti-programmed cell death 1 (PD-1) antibodies have antitumor activity in this disease, but little is known about the activity of anti-programmed cell death ligand 1 (PD-L1) antibodies in patients with mesothelioma. Objective: To assess the efficacy and safety of avelumab in a cohort of patients with previously treated mesothelioma. Design, Setting, and Participants: Phase 1b open-label study (JAVELIN Solid Tumor) in patients with unresectable mesothelioma that progressed after platinum and pemetrexed treatment, enrolled at 25 sites in 3 countries between September 9, 2014, and July 22, 2015. Interventions: Participants received avelumab, 10 mg/kg, every 2 weeks until disease progression, unacceptable toxic effects, or withdrawal from the study. Main Outcomes and Measures: Prespecified end points included confirmed best overall response based on Response Evaluation Criteria In Solid Tumors, version 1.1; duration of response; progression-free survival (PFS); overall survival (OS); PD-L1 expression-based analyses; and safety. Results: Of 53 patients treated with avelumab, the median age was 67 (range, 32-84) years; 32 (60%) were male. As of December 31, 2016, median follow-up was 24.8 (range, 16.8-27.8) months. Twenty patients (38%) had 3 or more previous lines of therapy (median, 2; range, 1-8). The confirmed objective response rate (ORR) was 9% (5 patients; 95% CI, 3.1%-20.7%), with complete response in 1 patient and partial response in 4 patients. Responses were durable (median, 15.2 months; 95% CI, 11.1 to not estimable months) and occurred in patients with PD-L1-positive tumors (3 of 16; ORR, 19%; 95% CI, 4.0%-45.6%) and PD-L1-negative tumors (2 of 27; ORR, 7%; 95% CI, 0.9%-24.3%) based on a 5% or greater PD-L1 cutoff. Disease control rate was 58% (31 patients). Median PFS was 4.1 (95% CI, 1.4-6.2) months, and the 12-month PFS rate was 17.4% (95% CI, 7.7%-30.4%). Median OS was 10.7 (95% CI, 6.4-20.2) months, and the median 12-month OS rate was 43.8% (95% CI, 29.8%-57.0%). Five patients (9%) had a grade 3 or 4 treatment-related adverse event, and 3 (6%) had a grade 3 or 4 immune-related, treatment-related adverse event. There were no treatment-related deaths. Conclusions and Relevance: Avelumab showed durable antitumor activity and disease control with an acceptable safety profile in a heavily pretreated cohort of patients with mesothelioma. Trial Registration: ClinicalTrials.gov identifier: NCT01772004.

Atezolizumab Plus nab-Paclitaxel in the Treatment of Metastatic Triple-Negative Breast Cancer With 2-Year Survival Follow-up: A Phase 1b Clinical Trial.

Importance: The humanized monoclonal antibody atezolizumab targets programmed death-ligand 1 and has demonstrated durable single-agent activity in a subset of metastatic triple-negative breast cancers. To extend the observed activity, combinatorial approaches are being tested with standard cytotoxic chemotherapies known to induce immunogenic tumor cell death. Objective: To examine the safety, tolerability, and preliminary clinical activity of atezolizumab plus nab-paclitaxel in metastatic triple-negative breast cancers. Design, Setting, and Participants: This phase 1b multicohort study enrolled 33 women with stage IV or locally recurrent triple-negative breast cancers and 0 to 2 lines of prior chemotherapy in the metastatic setting from December 8, 2014, to April 30, 2017, at 11 sites in the United States. The median follow-up was 24.4 months (95% CI, 22.1-28.8 months). Interventions: Patients received concurrent intravenous atezolizumab and intravenous nab-paclitaxel (minimum 4 cycles). Main Outcomes and Measures: The primary end point was safety and tolerability. Secondary end points included best overall response rate by Response Evaluation Criteria in Solid Tumors, version 1.1; objective response rate; duration of response; disease control rate; progression-free survival; overall survival; and biomarker analyses. Results: The 33 women had a median age of 55 years (range, 32-84 years) and received 1 or more doses of atezolizumab. All patients (100%) experienced at least 1 treatment-related adverse event, 24 patients (73%) experienced grade 3/4 adverse events, and 7 patients (21%) had grade 3/4 adverse events of special interest. No deaths were related to study treatment. The objective response rate was 39.4% (95% CI, 22.9%-57.9%), and the median duration of response was 9.1 months (95% CI, 2.0-20.9 months). The disease control rate was 51.5% (95% CI, 33.5%-69.2%). Median progression-free survival and overall survival were 5.5 months (95% CI, 5.1-7.7 months) and 14.7 months (95% CI, 10.1-not estimable), respectively. Concurrent nab-paclitaxel neither significantly changed biomarkers of the tumor immune microenvironment (programmed death-ligand 1, tumor-infiltrating lymphocytes, CD8) nor impaired atezolizumab systemic immune activation (expansion of proliferating CD8+ T cells, increase of CXCL10 chemokine). Conclusions and Relevance: In this phase 1b trial for metastatic triple-negative breast cancers, the combination of atezolizumab plus nab-paclitaxel had a manageable safety profile. Antitumor responses were observed, including in patients previously treated with a taxane. Trial Registration: ClinicalTrials.gov identifier: NCT01633970.