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).

Predictive correlates of response to the anti-PD-L1 antibody MPDL3280A in cancer patients.

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

Durvalumab as third-line or later treatment for advanced non-small-cell lung cancer (ATLANTIC): an open-label, single-arm, phase 2 study.

BACKGROUND: Immune checkpoint inhibitors are a new standard of care for patients with advanced non-small-cell lung cancer (NSCLC) without EGFR tyrosine kinase or anaplastic lymphoma kinase (ALK) genetic aberrations (EGFR-/ALK-), but clinical benefit in patients with EGFR mutations or ALK rearrangements (EGFR+/ALK+) has not been shown. We assessed the effect of durvalumab (anti-PD-L1) treatment in three cohorts of patients with NSCLC defined by EGFR/ALK status and tumour expression of PD-L1. METHODS: ATLANTIC is a phase 2, open-label, single-arm trial at 139 study centres in Asia, Europe, and North America. Eligible patients had advanced NSCLC with disease progression following at least two previous systemic regimens, including platinum-based chemotherapy (and tyrosine kinase inhibitor therapy if indicated); were aged 18 years or older; had a WHO performance status score of 0 or 1; and measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Key exclusion criteria included mixed small-cell lung cancer and NSCLC histology; previous exposure to any anti-PD-1 or anti-PD-L1 antibody; and any previous grade 3 or worse immune-related adverse event while receiving any immunotherapy agent. Patients in cohort 1 had EGFR+/ALK+ NSCLC with at least 25%, or less than 25%, of tumour cells with PD-L1 expression. Patients in cohorts 2 and 3 had EGFR-/ALK- NSCLC; cohort 2 included patients with at least 25%, or less than 25%, of tumour cells with PD-L1 expression, and cohort 3 included patients with at least 90% of tumour cells with PD-L1 expression. Patients received durvalumab (10 mg/kg) every 2 weeks, via intravenous infusion, for up to 12 months. Retreatment was allowed for patients who benefited but then progressed after completing 12 months. The primary endpoint was the proportion of patients with increased tumour expression of PD-L1 (defined as ≥25% of tumour cells in cohorts 1 and 2, and ≥90% of tumour cells in cohort 3) who achieved an objective response, assessed in patients who were evaluable for response per independent central review according to RECIST version 1.1. Safety was assessed in all patients who received at least one dose of durvalumab and for whom any post-dose data were available. The trial is ongoing, but is no longer open to accrual, and is registered with ClinicalTrials.gov, number NCT02087423. FINDINGS: Between Feb 25, 2014, and Dec 28, 2015, 444 patients were enrolled and received durvalumab: 111 in cohort 1, 265 in cohort 2, and 68 in cohort 3. Among patients with at least 25% of tumour cells expressing PD-L1 who were evaluable for objective response per independent central review, an objective response was achieved in 9 (12·2%, 95% CI 5·7-21·8) of 74 patients in cohort 1 and 24 (16·4%, 10·8-23·5) of 146 patients in cohort 2. In cohort 3, 21 (30·9%, 20·2-43·3) of 68 patients achieved an objective response. Grade 3 or 4 treatment-related adverse events occurred in 40 (9%) of 444 patients overall: six (5%) of 111 patients in cohort 1, 22 (8%) of 265 in cohort 2, and 12 (18%) of 68 in cohort 3. The most common treatment-related grade 3 or 4 adverse events were pneumonitis (four patients [1%]), elevated gamma-glutamyltransferase (four [1%]), diarrhoea (three [1%]), infusion-related reaction (three [1%]), elevated aspartate aminotransferase (two [<1%]), elevated transaminases (two [<1%]), vomiting (two [<1%]), and fatigue (two [<1%]). Treatment-related serious adverse events occurred in 27 (6%) of 444 patients overall: five (5%) of 111 patients in cohort 1, 14 (5%) of 265 in cohort 2, and eight (12%) of 68 in cohort 3. The most common serious adverse events overall were pneumonitis (five patients [1%]), fatigue (three [1%]), and infusion-related reaction (three [1%]). Immune-mediated events were manageable with standard treatment guidelines. INTERPRETATION: In patients with advanced and heavily pretreated NSCLC, the clinical activity and safety profile of durvalumab was consistent with that of other anti-PD-1 and anti-PD-L1 agents. Responses were recorded in all cohorts; the proportion of patients with EGFR-/ALK- NSCLC (cohorts 2 and 3) achieving a response was higher than the proportion with EGFR+/ALK+ NSCLC (cohort 1) achieving a response. The clinical activity of durvalumab in patients with EGFR+ NSCLC with ≥25% of tumour cells expressing PD-L1 was encouraging, and further investigation of durvalumab in patients with EGFR+/ALK+ NSCLC is warranted. FUNDING: AstraZeneca.

Safety, activity, and immune correlates of anti-PD-1 antibody in cancer.

BACKGROUND: Blockade of programmed death 1 (PD-1), an inhibitory receptor expressed by T cells, can overcome immune resistance. We assessed the antitumor activity and safety of BMS-936558, an antibody that specifically blocks PD-1. METHODS: We enrolled patients with advanced melanoma, non-small-cell lung cancer, castration-resistant prostate cancer, or renal-cell or colorectal cancer to receive anti-PD-1 antibody at a dose of 0.1 to 10.0 mg per kilogram of body weight every 2 weeks. Response was assessed after each 8-week treatment cycle. Patients received up to 12 cycles until disease progression or a complete response occurred. RESULTS: A total of 296 patients received treatment through February 24, 2012. Grade 3 or 4 drug-related adverse events occurred in 14% of patients; there were three deaths from pulmonary toxicity. No maximum tolerated dose was defined. Adverse events consistent with immune-related causes were observed. Among 236 patients in whom response could be evaluated, objective responses (complete or partial responses) were observed in those with non-small-cell lung cancer, melanoma, or renal-cell cancer. Cumulative response rates (all doses) were 18% among patients with non-small-cell lung cancer (14 of 76 patients), 28% among patients with melanoma (26 of 94 patients), and 27% among patients with renal-cell cancer (9 of 33 patients). Responses were durable; 20 of 31 responses lasted 1 year or more in patients with 1 year or more of follow-up. To assess the role of intratumoral PD-1 ligand (PD-L1) expression in the modulation of the PD-1-PD-L1 pathway, immunohistochemical analysis was performed on pretreatment tumor specimens obtained from 42 patients. Of 17 patients with PD-L1-negative tumors, none had an objective response; 9 of 25 patients (36%) with PD-L1-positive tumors had an objective response (P=0.006). CONCLUSIONS: Anti-PD-1 antibody produced objective responses in approximately one in four to one in five patients with non-small-cell lung cancer, melanoma, or renal-cell cancer; the adverse-event profile does not appear to preclude its use. Preliminary data suggest a relationship between PD-L1 expression on tumor cells and objective response. (Funded by Bristol-Myers Squibb and others; ClinicalTrials.gov number, NCT00730639.).

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.

Microtube device for selectin-mediated capture of viable circulating tumor cells from blood.

BACKGROUND: Circulating tumor cells (CTCs) can be used clinically to treat cancer. As a diagnostic tool, the CTC count can be used to follow disease progression, and as a treatment tool, CTCs can be used to rapidly develop personalized therapeutic strategies. To be effectively used, however, CTCs must be isolated at high purity without inflicting cellular damage. METHODS: We designed a microscale flow device with a functionalized surface of E-selectin and antibody molecules against epithelial markers. The device was additionally enhanced with a halloysite nanotube coating. We created model samples in which a known number of labeled cancer cells were suspended in healthy whole blood to determine device capture efficiency. We then isolated and cultured primary CTCs from buffy coat samples of patients diagnosed with metastatic cancer. RESULTS: Approximately 50% of CTCs were captured from model samples. Samples from 12 metastatic cancer patients and 8 healthy participants were processed in nanotube-coated or smooth devices to isolate CTCs. We isolated 20-704 viable CTCs per 3.75-mL sample, achieving purities of 18%-80% CTCs. The nanotube-coated surface significantly improved capture purities (P = 0.0004). Experiments suggested that this increase in purity was due to suppression of leukocyte spreading. CONCLUSIONS: The device successfully isolates viable CTCs from both blood and buffy coat samples. The approximately 50% capture rate with purities >50% with the nanotube coating demonstrates the functionality of this device in a clinical setting and opens the door for personalized cancer therapies.

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.

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.

A phase II multicenter study of ipilimumab with or without dacarbazine in chemotherapy-naïve patients with advanced melanoma.

OBJECTIVE: Ipilimumab is a fully human, anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) monoclonal antibody that has demonstrated antitumor activity in advanced melanoma. We evaluated the safety and efficacy of ipilimumab alone and in combination with dacarbazine (DTIC) in patients with unresectable, metastatic melanoma. METHODS: Chemotherapy-naïve patients were randomized in this multicenter, phase II study to receive ipilimumab at 3 mg/kg every 4 weeks for four doses either alone or with up to six 5-day courses of DTIC at 250 mg/m(2)/day. The primary efficacy endpoint was objective response rate. RESULTS: Seventy-two patients were treated per-protocol (ipilimumab plus DTIC, n = 35; ipilimumab, n = 37). The objective response rate was 14.3% (95% CI, 4.8-30.3) with ipilimumab plus DTIC and was 5.4% (95% CI, 0.7-18.2) with ipilimumab alone. At a median follow-up of 20.9 and 16.4 months for ipilimumab plus DTIC (n = 32) and ipilimumab alone (n = 32), respectively, median overall survival was 14.3 months (95% CI, 10.2-18.8) and 11.4 months (95% CI, 6.1-15.6); 12-month, 24-month, and 36-month survival rates were 62%, 24% and 20% for the ipilimumab plus DTIC group and were 45%, 21% and 9% for the ipilimumab alone group, respectively. Immune-related adverse events were, in general, medically manageable and occurred in 65.7% of patients in the combination group versus 53.8% in the monotherapy group, with 17.1% and 7.7% ≥grade 3, respectively. CONCLUSION: Ipilimumab therapy resulted in clinically meaningful responses in advanced melanoma patients, and the results support further investigations of ipilimumab in combination with DTIC.

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 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.

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.