Phase I/II sequencing study of azacitidine, epacadostat, and pembrolizumab in advanced solid tumors.

BACKGROUND: Indoleamine 2,3-dioxygenase 1 (IDO1), an interferon-inducible enzyme, contributes to tumor immune intolerance. Immune checkpoint inhibition may increase interferon levels; combining IDO1 inhibition with immune checkpoint blockade represents an attractive strategy. Epigenetic agents trigger interferon responses and may serve as an immunotherapy priming method. We evaluated whether epigenetic therapy plus IDO1 inhibition and immune checkpoint blockade confers clinical benefit to patients with advanced solid tumors. METHODS: ECHO-206 was a Phase I/II study where treatment-experienced patients with advanced solid tumors (N = 70) received azacitidine plus an immunotherapy doublet (epacadostat [IDO1 inhibitor] and pembrolizumab). Sequencing of treatment was also assessed. Primary endpoints were safety/tolerability (Phase I), maximum tolerated dose (MTD) or pharmacologically active dose (PAD; Phase I), and investigator-assessed objective response rate (ORR; Phase II). RESULTS: In Phase I, no dose-limiting toxicities were reported, the MTD was not reached; a PAD was not determined. ORR was 5.7%, with four partial responses. The most common treatment-related adverse events (AEs) were fatigue (42.9%) and nausea (42.9%). Twelve (17.1%) patients experienced ≥1 fatal AE, one of which (asthenia) was treatment-related. CONCLUSIONS: Although the azacitidine-epacadostat-pembrolizumab regimen was well tolerated, it was not associated with substantial clinical response in patients with advanced solid tumors previously exposed to immunotherapy.

Characterization of INCB086550: A Potent and Novel Small-Molecule PD-L1 Inhibitor.

Blocking the activity of the programmed cell death protein 1 (PD-1) inhibitory receptor with therapeutic antibodies against either the ligand (PD-L1) or PD-1 itself has proven to be an effective treatment modality for multiple cancers. Contrasting with antibodies, small molecules could demonstrate increased tissue penetration, distinct pharmacology, and potentially enhanced antitumor activity. Here, we describe the identification and characterization of INCB086550, a novel, oral, small-molecule PD-L1 inhibitor. In vitro, INCB086550 selectively and potently blocked the PD-L1/PD-1 interaction, induced PD-L1 dimerization and internalization, and induced stimulation-dependent cytokine production in primary human immune cells. In vivo, INCB086550 reduced tumor growth in CD34+ humanized mice and induced T-cell activation gene signatures, consistent with PD-L1/PD-1 pathway blockade. Preliminary data from an ongoing phase I study confirmed PD-L1/PD-1 blockade in peripheral blood cells, with increased immune activation and tumor growth control. These data support continued clinical evaluation of INCB086550 as an alternative to antibody-based therapies. SIGNIFICANCE: We have identified a potent small-molecule inhibitor of PD-L1, INCB086550, which has biological properties similar to PD-L1/PD-1 monoclonal antibodies and may represent an alternative to antibody therapy. Preliminary clinical data in patients demonstrated increased immune activation and tumor growth control, which support continued clinical evaluation of this approach. See related commentary by Capparelli and Aplin, p. 1413. This article is highlighted in the In This Issue feature, p. 1397.

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.

A randomized, double-blind, phase 2 study of ruxolitinib or placebo in combination with capecitabine in patients with advanced HER2-negative breast cancer and elevated C-reactive protein, a marker of systemic inflammation.

PURPOSE: The Janus-associated kinase (JAK)/signal transducer and activator of transcription pathway is a key regulator of inflammatory signaling, associated with tumorigenesis, cell survival, and progression. This randomized phase 2 trial evaluated the efficacy and safety of the addition of ruxolitinib, a JAK1/JAK2 inhibitor, to capecitabine in patients with HER2-negative advanced breast cancer and high systemic inflammation (modified Glasgow Prognostic Score [mGPS] ≥ 1). METHODS: Patients with ≤ 2 prior chemotherapy regimens for advanced or metastatic disease or hormone receptor-positive patients with disease progression on prior hormonal therapies were randomized 1:1 to 21-day cycles of ruxolitinib (n = 76) or placebo (n = 73) plus capecitabine. The primary endpoint was overall survival (OS). RESULTS: Baseline characteristics were well balanced between groups. For ruxolitinib plus capecitabine versus placebo plus capecitabine, median OS was 11.2 months versus 10.9 months (log-rank test P = 0.762); median progression-free survival (PFS) was 4.5 months versus 2.5 months (log-rank test P = 0.151); and overall response rate (ORR) was 28.9% versus 13.7% (Cochran-Mantel-Haenszel test P = 0.024), respectively. A more favorable change in health-related quality of life (HRQoL) was observed with ruxolitinib plus capecitabine versus placebo plus capecitabine. Both regimens were generally tolerable. A higher incidence of grade 3/4 anemia (25.4% vs 5.6%) and a lower incidence of grade 3/4 palmar-plantar erythrodysesthesia (1.4% vs 12.7%) occurred with ruxolitinib plus capecitabine versus placebo plus capecitabine. CONCLUSIONS: The addition of ruxolitinib to capecitabine for patients with advanced breast cancer and high systemic inflammation was generally tolerable; ORR was numerically greater, a more favorable change in HRQoL was observed, but neither OS nor PFS was improved compared with placebo plus capecitabine.

A phase 1 study of oral ridaforolimus in pediatric patients with advanced solid tumors.

PURPOSE: Ridaforolimus is an investigational, potent, selective mTOR inhibitor. This study was conducted to determine the recommended phase 2 dose (RP2D), maximum tolerated dose, safety, pharmacokinetics, and antitumor activity of oral ridaforolimus in children with advanced solid tumors. EXPERIMENTAL DESIGN: In this phase 1, multicenter, open-label study in children aged 6 to <18 years with advanced solid tumors, ridaforolimus was administered orally for 5 consecutive days/week in 28-day cycles until progression, unacceptable toxicity, or consent withdrawal. Dose started at 22 mg/m2 and increased to 28 mg/m2 and 33 mg/m2, followed by expansion at the RP2D. RESULTS: Twenty patients were treated; 18 were evaluable for dose-limiting toxicities. One dose-limiting toxicity (grade 3 increased alanine aminotransferase) occurred in 1 patient at 33 mg/m2. Dose escalation concluded at 33 mg/m2; the maximum tolerated dose was not determined. The most common treatment-related adverse events (frequency ≥40%) were manageable grade 1-2 stomatitis, thrombocytopenia, hypertriglyceridemia, increased alanine aminotransferase, fatigue, hypercholesterolemia, anemia, and increased aspartate aminotransferase. Ridaforolimus exposure at 28 mg/m2 and 33 mg/m2 exceeded adult target levels. The RP2D for oral ridaforolimus in children was defined as 33 mg/m2. Four patients received at least 4 cycles; 2 with pineoblastoma and diffuse intrinsic pontine glioma had stable disease for 12 and 46 cycles, respectively. CONCLUSIONS: Ridaforolimus is orally bioavailable and well tolerated in children with advanced solid tumors. The RP2D (33 mg/m2, 5 days/week) exceeds the adult RP2D. The favorable toxicity and pharmacokinetic profiles may allow for combination therapy, a promising therapeutic option in pediatric malignancies.

Phase 1 study of dalotuzumab monotherapy and ridaforolimus-dalotuzumab combination therapy in paediatric patients with advanced solid tumours.

AIM: Dalotuzumab is a highly specific, humanised immunoglobulin G1 monoclonal antibody against insulin-like growth factor receptor 1. This multicenter phase 1 study (NCT01431547) explored the safety and pharmacokinetics of dalotuzumab monotherapy (part 1) and the combination of dalotuzumab with the mammalian target of rapamycin inhibitor ridaforolimus (part 2) in paediatric patients with advanced solid tumours. METHODS: Dalotuzumab was administered intravenously every 3 weeks starting at 900 mg/m(2) and escalating to 1200 and 1500 mg/m(2). Combination therapy included intravenous dalotuzumab at the defined single-agent recommended phase 2 dose (RP2D) and oral ridaforolimus 28 mg/m(2) daily (days 1-5), repeated weekly. Pharmacokinetic studies were performed to evaluate the mean serum trough dalotuzumab concentration, which guided the RP2D. RESULTS: Twenty-four patients were enrolled (part 1, n = 20; part 2, n = 4). No dose-limiting toxicities were observed in patients receiving dalotuzumab alone. One patient experienced dose-limiting stomatitis in the combination arm. Pharmacokinetic data showed dose-dependent increases in exposure (area under the curve from zero to infinity [AUC0-∞]) (87,900, 164,000, and 186,000 h*mg/ml for the 900, 1200, and 1500 mg/m(2) dose levels, respectively), maximum serum concentration (Cmax) (392, 643, and 870 mg/ml), and serum trough concentration (Ctrough) (67.1, 71.6, and 101 mg/ml). The mean half-life was 265, 394, and 310 h, respectively. Dalotuzumab pharmacokinetics were not affected by coadministration with ridaforolimus. One of six patients with Ewing sarcoma had confirmed partial response to dalotuzumab monotherapy at 900 mg/m(2). Time to response was 41 d, and progression occurred at 126 d. CONCLUSION: Dalotuzumab was well tolerated in paediatric patients with advanced solid malignancies. The RP2D of dalotuzumab is 900 mg/m(2) (ClinicalTrials.gov identifier: NCT01431547, Protocol PN062).

MESOMARK: a potential test for malignant pleural mesothelioma.

BACKGROUND: Soluble mesothelin-related peptides (SMRP)have been reported to be potential biomarkers for malignant pleural mesothelioma (MPM). We report analytical and preliminary clinical studies of MESOMARK, a quantitative assay for SMRP. METHODS: The MESOMARK assay is a 2-step immunoenzymatic assay in an ELISA format with a 6-point calibration curve (0-32 nmol/L). We assessed analytical imprecision, analyte stability, and analytical interferences. We measured SMRP by this assay in 409 apparently healthy individuals (reference interval study), 177 patients with nonmalignant conditions, and 500 cancer patients, including 88 with MPM. RESULTS: The limit of detection was 0.16 nmol/L. At 2-19 nmol/L, intraassay imprecision (CV) was 1.1%-5.3%, and total imprecision was 4.0%-11.0%. The mean dilution recovery for 5 samples was 109% (range, 99%-113%). No interference was seen from added bilirubin (200 mg/L), hemoglobin (500 mg/L), triglycerides (30 g/L), chemotherapeutic agents, or other tested substances. Recombinant mesothelin was stable in serum upon freeze/thaw at -70 degrees C and upon storage for at least 7 days at 2-8 degrees C. The 99(th) percentile of the reference group was 1.5 nmol/L [95% confidence interval (CI), 1.2-1.6 nmol/L; n = 409], and mean SMRP was significantly higher in sera from patients with MPM (7.5 nmol/L; 95% CI, 2.8-12.1 nmol/L; n = 88). SMRP was increased in 52% and 5% of MPM patients and asbestos-exposed individuals, respectively. Concentrations in other nonmalignant and malignant conditions were similar to those in healthy controls. CONCLUSIONS: The MESOMARK assay is analytically robust and may be useful for the detection and management of mesothelioma.

Detection of newly diagnosed bladder cancer, bladder cancer recurrence and bladder cancer in patients with hematuria using quantitative rt-PCR of urinary survivin.

BACKGROUND/AIMS: Survivin mRNA in urine was measured to detect newly diagnosed bladder cancer, bladder cancer recurrence and bladder cancer in patients with hematuria. METHODS: We have investigated urinary survivin mRNA of 118 voided urine specimens, including 24 patients with bladder cancer, 50 with bladder cancer history, 68 not known to harbor bladder cancer, and 55 with hematuria using quantitative reverse transcriptase polymerase chain reaction. beta-Actin mRNA expression was also examined and used as an endogenous control to ensure validity of the assay for each sample. RESULTS: The survivin expression in urological patient urine had sensitivities and specificities for all patients of 79 and 93%, for detection of newly diagnosed bladder cancer 83 and 95%, for bladder cancer recurrence 82 and 90%, and for bladder cancer in patients with hematuria 80 and 90%. CONCLUSION: Our results indicate that quantitative reverse transcriptase polymerase chain reaction of urinary survivin is a sensitive, noninvasive and highly specific assay to detect both newly diagnosed bladder cancer and bladder cancer recurrence. Furthermore, this assay may be useful in stratifying the hematuria population in urological practice.

Subtelomeric deletions of chromosome 6p: molecular and cytogenetic characterization of three new cases with phenotypic overlap with Ritscher-Schinzel (3C) syndrome.

We have identified six children in three families with subtelomeric deletions of 6p25 and a recognizable phenotype consisting of ptosis, posterior embryotoxon, optic nerve abnormalities, mild glaucoma, Dandy-Walker malformation, hydrocephalus, atrial septal defect, patent ductus arteriosus, and mild mental retardation. There is considerable clinical overlap between these children and individuals with the Ritscher-Schinzel (or cranio-cerebello-cardiac (3C)) syndrome (OMIM #220210). Clinical features of 3C syndrome include craniofacial anomalies (macrocephaly, prominent forehead and occiput, foramina parietalia, hypertelorism, down-slanting palpebral fissures, ocular colobomas, depressed nasal bridge, narrow or cleft palate, and low-set ears), cerebellar malformations (variable manifestations of a Dandy-Walker malformation with moderate mental retardation), and cardiac defects (primarily septal defects). Since the original report, over 25 patients with 3C syndrome have been reported. Recessive inheritance has been postulated based on recurrence in siblings born to unaffected parents and parental consanguinity in two familial cases. Molecular and cytogenetic mapping of the 6p deletions in these three families with subtelomeric deletions of chromosome 6p have defined a 1.3 Mb minimally deleted critical region. To determine if 6p deletions are common in 3C syndrome, we analyzed seven unrelated individuals with 3C syndrome for deletions of this region. Three forkhead genes (FOXF1 and FOXQ1 from within the critical region, and FOXC1 proximal to this region) were evaluated as potential candidate disease genes for this disorder. No deletions or disease-causing mutations were identified.