Phase 1b study of pan-AKT inhibitor vevorisertib alone or with paclitaxel or fulvestrant in PIK3CA/AKT/PTEN-mutated advanced solid tumors.

BACKGROUND: In this first-in-human phase 1b study (ClinicalTrials.gov identifier NCT02761694) of advanced solid tumors with PIK3CA/AKT/PTEN mutations, the authors investigated the safety and efficacy of the pan-AKT inhibitor vevorisertib (MK-4440; ARQ 751) as monotherapy or with paclitaxel or fulvestrant. METHODS: Patients with histologically confirmed, advanced or recurrent, PIK3CA/AKT/PTEN-mutated solid tumors, measurable disease according to Response Evaluation Criteria in Solid Tumors, version 1.1, and an Eastern Cooperative Oncology Group performance status ≤1 received vevorisertib (dose range, 5-100 mg) alone or with paclitaxel 80 mg/m2 or fulvestrant 500 mg. The primary end point was safety and tolerability. Secondary end points included pharmacokinetics and the objective response rate according to Response Evaluation Criteria in Solid Tumors, version 1.1. RESULTS: Of 78 patients enrolled, 58 received vevorisertib monotherapy, 10 received vevorisertib plus paclitaxel, and nine received vevorisertib plus fulvestrant. Dose-limiting toxicity occurred in three patients (vevorisertib monotherapy, n = 2 [grade 3 pruritic and maculopapular rashes]; vevorisertib plus paclitaxel, n = 1 [grade 1 asthenia]). Across doses, treatment-related AEs occurred in 46 patients (79%) with vevorisertib monotherapy, in 10 patients (100%) with vevorisertib plus paclitaxel, and in nine patients (100%) with vevorisertib plus fulvestrant; and grade 3 treatment-related AEs occurred in 13 (22%), 7 (70%), and 3 (33%) patients, respectively. No grade 4/5 treatment-related AEs occurred. Maximum vevorisertib concentrations were reached 1-4 hours after dosing; the elimination half-life ranged from 8.8 to 19.3 hours. The objective response rate was 5% with vevorisertib monotherapy (three partial responses), 20% with vevorisertib plus paclitaxel (two partial responses), and 0% with vevorisertib plus fulvestrant. CONCLUSIONS: Vevorisertib alone or with paclitaxel or fulvestrant had a manageable safety profile, and vevorisertib alone or with paclitaxel had minimal to modest antitumor activity in this patient population with PIK3CA/AKT/PTEN-mutated advanced solid tumors. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02761694.

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

There have been no major advances for the treatment of metastatic urothelial bladder cancer (UBC) in the last 30 years. Chemotherapy is still the standard of care. Patient outcomes, especially for those in whom chemotherapy is not effective or is poorly tolerated, remain poor. One hallmark of UBC is the presence of high rates of somatic mutations. These alterations may enhance the ability of the host immune system to recognize tumour cells as foreign owing to an increased number of antigens. However, these cancers may also elude immune surveillance and eradication through the expression of programmed death-ligand 1 (PD-L1; also called CD274 or B7-H1) in the tumour microenvironment. Therefore, we examined the anti-PD-L1 antibody MPDL3280A, a systemic cancer immunotherapy, for the treatment of metastatic UBC. MPDL3280A is a high-affinity engineered human anti-PD-L1 monoclonal immunoglobulin-G1 antibody that inhibits the interaction of PD-L1 with PD-1 (PDCD1) and B7.1 (CD80). Because PD-L1 is expressed on activated T cells, MPDL3280A was engineered with a modification in the Fc domain that eliminates antibody-dependent cellular cytotoxicity at clinically relevant doses to prevent the depletion of T cells expressing PD-L1. Here we show that MPDL3280A has noteworthy activity in metastatic UBC. Responses were often rapid, with many occurring at the time of the first response assessment (6 weeks) and nearly all were ongoing at the data cutoff. This phase I expansion study, with an adaptive design that allowed for biomarker-positive enriched cohorts, demonstrated that tumours expressing PD-L1-positive tumour-infiltrating immune cells had particularly high response rates. Moreover, owing to the favourable toxicity profile, including a lack of renal toxicity, patients with UBC, who are often older and have a higher incidence of renal impairment, may be better able to tolerate MPDL3280A versus chemotherapy. These results suggest that MPDL3280A may have an important role in treating UBC-the drug received breakthrough designation status by the US Food and Drug Administration (FDA) in June 2014.

First-in-human, phase I study of PF-06647263, an anti-EFNA4 calicheamicin antibody-drug conjugate, in patients with advanced solid tumors.

PF-06647263, a novel antibody-drug conjugate consisting of an anti-EFNA4 antibody linked to a calicheamicin payload, has shown potent antitumor activity in human xenograft tumor models, including triple-negative breast cancer (TNBC). In the dose-escalation part 1 of this multicenter, open-label, phase I study (NCT02078752), successive cohorts of patients (n, 48) with advanced solid tumors and no available standard therapy received PF-06647263 every 3 weeks (Q3W) or every week (QW), following a modified toxicity probability interval (mTPI) method (initial dosing: 0.015 mg/kg Q3W). Primary objective in part 1 was to estimate the maximum tolerated dose (MTD) and select the recommended phase 2 dose (RP2D). In part 2 (dose-expansion cohort), 12 patients with pretreated, metastatic TNBC received PF-06647263 at the RP2D to further evaluate tumor response and overall safety. PF-06647263 QW administration (n, 23) was better tolerated than the Q3W regimen (n, 25) with only 1 DLT reported (thrombocytopenia). The most common AEs with the QW regimen (fatigue, nausea, vomiting, mucosal inflammation, thrombocytopenia, and diarrhea) were mostly mild to moderate in severity. The MTD was not estimated. PF-06647263 exposures increased in a dose-related manner across the doses evaluated. The RP2D was determined to be 0.015 mg/kg QW. Six (10%) patients achieved a confirmed partial response and 22 (36.7%) patients had stable disease. No correlations were observed between tumor responses and EFNA4 expression levels. Study findings showed manageable safety and favorable PK for PF-06647263 administered QW at the RP2D, with preliminary evidence of limited antitumor activity in patients with TNBC and ovarian cancer.

Derazantinib (ARQ 087) in advanced or inoperable FGFR2 gene fusion-positive intrahepatic cholangiocarcinoma.

BACKGROUND: Next-generation sequencing has identified actionable genetic aberrations in intrahepatic cholangiocarcinomas (iCCA), including the fibroblast growth factor receptor 2 (FGFR2) fusions. Derazantinib (ARQ 087), an orally bioavailable, multi-kinase inhibitor with potent pan-FGFR activity, has shown preliminary therapeutic activity against FGFR2 fusion-positive iCCA. METHODS: This multicentre, phase 1/2, open-label study enrolled adult patients with unresectable iCCA with FGFR2 fusion, who progressed, were intolerant or not eligible to first-line chemotherapy (NCT01752920). Subjects received derazantinib in continuous daily doses. Tumour response was assessed according to RECIST 1.1 every 8 weeks. RESULTS: Twenty-nine patients (18 women/11 men; median age, 58.7 years), 2 treatment-naive and 27 who progressed after at least one prior systemic therapy, were enrolled. Overall response rate was 20.7%, disease control rate was 82.8%. Estimated median progression-free survival was 5.7 months (95% CI: 4.04-9.2 months). Treatment-related adverse events (AE) were observed in 27 patients (93.1%, all grades), including asthenia/fatigue (69.0%), eye toxicity (41.4%), and hyperphosphatemia (75.9%). Grade ≥ 3 AEs occurred in 8 patients (27.6%). CONCLUSION: Derazantinib demonstrated encouraging anti-tumour activity and a manageable safety profile in patients with advanced, unresectable iCCA with FGFR2 fusion who progressed after chemotherapy. A pivotal trial of derazantinib in iCCA is ongoing (NCT03230318).

Safety, clinical activity and biomarker assessments of atezolizumab from a Phase I study in advanced/recurrent ovarian and uterine cancers.

OBJECTIVE: Patients with advanced/recurrent epithelial ovarian and uterine cancers have limited treatment options beyond platinum chemotherapy. Both tumor types can express programmed death-ligand 1 (PD-L1), providing a potential therapeutic target for these patients. Here we present data from the ovarian and uterine cancer cohorts of the Phase I atezolizumab monotherapy study (PCD4989g). METHODS: This Phase I, multi-center, first-in-human, open-label, dose-escalation/expansion clinical trial investigated single-agent atezolizumab in cohorts of patients with recurrent epithelial ovarian or uterine cancer. The primary objective was to evaluate the safety and tolerability of single-agent atezolizumab. Anti-tumor activity and preliminary assessment of potential biomarkers were evaluated as secondary and exploratory objectives, respectively. RESULTS: The ovarian and uterine cancer cohorts enrolled 12 and 15 patients, respectively (10 [83%] and 5 [33%], respectively, had PD-L1 ≥ 5% on tumor-infiltrating immune cells). Atezolizumab was generally well tolerated with no new safety signals identified. The safety profiles in both cohorts were consistent with the known profile of atezolizumab monotherapy. Treatment-related adverse events (AEs) were mostly Grade ≤ 2, with no treatment-related Grade ≥ 4 AEs reported. Preliminary anti-tumor activity, with long durations of response, was observed in 2 patients from each cohort (ovarian cancer, 8.1 and 30.6+ months; uterine cancer, 7.3 and 16.6+ months). High microsatellite instability and tumor mutational burden were noted in the responders from the uterine cancer cohort. CONCLUSIONS: Atezolizumab monotherapy was well tolerated in patients with epithelial ovarian or uterine cancer and may have clinical activity warranting further investigation. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01375842.

Long-term effects of crizotinib in ALK-positive tumors (excluding NSCLC): A phase 1b open-label study.

Crizotinib, an inhibitor of anaplastic lymphoma kinase (ALK), MET, and ROS1, is approved for treatment of patients with ALK-positive or ROS1-positive advanced non-small-cell lung cancer (NSCLC). However, ALK rearrangements are also implicated in other malignancies, including anaplastic large-cell lymphoma and inflammatory myofibroblastic tumors (IMTs). In this ongoing, multicenter, single-arm, open-label phase 1b study (PROFILE 1013; NCT01121588), patients with ALK-positive advanced malignancies other than NSCLC were to receive a starting dose of crizotinib 250 mg twice daily. Primary endpoints were safety and objective responses based on Response Evaluation Criteria in Solid Tumors version 1.1 or National Cancer Institute International Response Criteria. Forty-four patients were enrolled (lymphoma, n = 18; IMT, n = 9; other tumors, n = 17). The objective response rate was 53% (95% confidence interval [CI], 28-77) for lymphoma, with 8 complete responses (CRs) and 1 partial response (PR); 67% (95% CI, 30-93) for IMTs, with 1 CR and 5 PRs; and 12% (95% CI, 2-36) for other tumors, with 2 PRs in patients affected by colon carcinoma and medullary thyroid cancer, respectively. The median duration of treatment was almost 3 years for patients with lymphoma and IMTs, with 2-year progression-free survival of 63% and 67%, respectively. The most common treatment-related adverse events were diarrhea (45.5%) and vision disorders (45.5%), mostly grade 1. These findings indicate strong and durable activity of crizotinib in ALK-positive lymphomas and IMTs. The safety profile was consistent with the known safety profile of crizotinib even with long-term treatment.

Atezolizumab versus docetaxel for patients with previously treated non-small-cell lung cancer (POPLAR): a multicentre, open-label, phase 2 randomised controlled trial.

BACKGROUND: Outcomes are poor for patients with previously treated, advanced or metastatic non-small-cell lung cancer (NSCLC). The anti-programmed death ligand 1 (PD-L1) antibody atezolizumab is clinically active against cancer, including NSCLC, especially cancers expressing PD-L1 on tumour cells, tumour-infiltrating immune cells, or both. We assessed efficacy and safety of atezolizumab versus docetaxel in previously treated NSCLC, analysed by PD-L1 expression levels on tumour cells and tumour-infiltrating immune cells and in the intention-to-treat population. METHODS: In this open-label, phase 2 randomised controlled trial, patients with NSCLC who progressed on post-platinum chemotherapy were recruited in 61 academic medical centres and community oncology practices across 13 countries in Europe and North America. Key inclusion criteria were Eastern Cooperative Oncology Group performance status 0 or 1, measurable disease by Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1), and adequate haematological and end-organ function. Patients were stratified by PD-L1 tumour-infiltrating immune cell status, histology, and previous lines of therapy, and randomly assigned (1:1) by permuted block randomisation (with a block size of four) using an interactive voice or web system to receive intravenous atezolizumab 1200 mg or docetaxel 75 mg/m(2) once every 3 weeks. Baseline PD-L1 expression was scored by immunohistochemistry in tumour cells (as percentage of PD-L1-expressing tumour cells TC3≥50%, TC2≥5% and <50%, TC1≥1% and <5%, and TC0<1%) and tumour-infiltrating immune cells (as percentage of tumour area: IC3≥10%, IC2≥5% and <10%, IC1≥1% and <5%, and IC0<1%). The primary endpoint was overall survival in the intention-to-treat population and PD-L1 subgroups at 173 deaths. Biomarkers were assessed in an exploratory analysis. We assessed safety in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT01903993. FINDINGS: Patients were enrolled between Aug 5, 2013, and March 31, 2014. 144 patients were randomly allocated to the atezolizumab group, and 143 to the docetaxel group. 142 patients received at least one dose of atezolizumab and 135 received docetaxel. Overall survival in the intention-to-treat population was 12·6 months (95% CI 9·7-16·4) for atezolizumab versus 9·7 months (8·6-12·0) for docetaxel (hazard ratio [HR] 0·73 [95% CI 0·53-0·99]; p=0·04). Increasing improvement in overall survival was associated with increasing PD-L1 expression (TC3 or IC3 HR 0·49 [0·22-1·07; p=0·068], TC2/3 or IC2/3 HR 0·54 [0·33-0·89; p=0·014], TC1/2/3 or IC1/2/3 HR 0·59 [0·40-0·85; p=0·005], TC0 and IC0 HR 1·04 [0·62-1·75; p=0·871]). In our exploratory analysis, patients with pre-existing immunity, defined by high T-effector-interferon-γ-associated gene expression, had improved overall survival with atezolizumab. 11 (8%) patients in the atezolizumab group discontinued because of adverse events versus 30 (22%) patients in the docetaxel group. 16 (11%) patients in the atezolizumab group versus 52 (39%) patients in the docetaxel group had treatment-related grade 3-4 adverse events, and one (<1%) patient in the atezolizumab group versus three (2%) patients in the docetaxel group died from a treatment-related adverse event. INTERPRETATION: Atezolizumab significantly improved survival compared with docetaxel in patients with previously treated NSCLC. Improvement correlated with PD-L1 immunohistochemistry expression on tumour cells and tumour-infiltrating immune cells, suggesting that PD-L1 expression is predictive for atezolizumab benefit. Atezolizumab was well tolerated, with a safety profile distinct from chemotherapy. FUNDING: F Hoffmann-La Roche/Genentech Inc.

Nanoliposomal irinotecan with fluorouracil and folinic acid in metastatic pancreatic cancer after previous gemcitabine-based therapy (NAPOLI-1): a global, randomised, open-label, phase 3 trial.

BACKGROUND: Nanoliposomal irinotecan showed activity in a phase 2 study in patients with metastatic pancreatic ductal adenocarcinoma previously treated with gemcitabine-based therapies. We assessed the effect of nanoliposomal irinotecan alone or combined with fluorouracil and folinic acid in a phase 3 trial in this population. METHODS: We did a global, phase 3, randomised, open-label trial at 76 sites in 14 countries. Eligible patients with metastatic pancreatic ductal adenocarcinoma previously treated with gemcitabine-based therapy were randomly assigned (1:1) using an interactive web response system at a central location to receive either nanoliposomal irinotecan monotherapy (120 mg/m(2) every 3 weeks, equivalent to 100 mg/m(2) of irinotecan base) or fluorouracil and folinic acid. A third arm consisting of nanoliposomal irinotecan (80 mg/m(2), equivalent to 70 mg/m(2) of irinotecan base) with fluorouracil and folinic acid every 2 weeks was added later (1:1:1), in a protocol amendment. Randomisation was stratified by baseline albumin, Karnofsky performance status, and ethnic origin. Treatment was continued until disease progression or intolerable toxic effects. The primary endpoint was overall survival, assessed in the intention-to-treat population. The primary analysis was planned after 305 events. Safety was assessed in all patients who had received study drug. This trial is registered at ClinicalTrials.gov, number NCT01494506. FINDINGS: Between Jan 11, 2012, and Sept 11, 2013, 417 patients were randomly assigned either nanoliposomal irinotecan plus fluorouracil and folinic acid (n=117), nanoliposomal irinotecan monotherapy (n=151), or fluorouracil and folinic acid (n=149). After 313 events, median overall survival in patients assigned nanoliposomal irinotecan plus fluorouracil and folinic acid was 6.1 months (95% CI 4.8-8.9) vs 4.2 months (3.3-5.3) with fluorouracil and folinic acid (hazard ratio 0.67, 95% CI 0.49-0.92; p=0.012). Median overall survival did not differ between patients assigned nanoliposomal irinotecan monotherapy and those allocated fluorouracil and folinic acid (4.9 months [4.2-5.6] vs 4.2 months [3.6-4.9]; 0.99, 0.77-1.28; p=0.94). The grade 3 or 4 adverse events that occurred most frequently in the 117 patients assigned nanoliposomal irinotecan plus fluorouracil and folinic acid were neutropenia (32 [27%]), diarrhoea (15 [13%]), vomiting (13 [11%]), and fatigue (16 [14%]). INTERPRETATION: Nanoliposomal irinotecan in combination with fluorouracil and folinic acid extends survival with a manageable safety profile in patients with metastatic pancreatic ductal adenocarcinoma who previously received gemcitabine-based therapy. This agent represents a new treatment option for this population. FUNDING: Merrimack Pharmaceuticals.

Detection of an ALK Fusion in Colorectal Carcinoma by Hybrid Capture-Based Assay of Circulating Tumor DNA.

ALK rearrangements have been observed in 0.05%-2.5% of patients with colorectal cancers (CRCs) and are predicted to be oncogenic drivers largely mutually exclusive of KRAS, NRAS, or BRAF alterations. Here we present the case of a patient with metastatic CRC who was treatment naïve at the time of molecular testing. Initial ALK immunohistochemistry (IHC) staining was negative, but parallel genomic profiling of both circulating tumor DNA (ctDNA) and tissue using similar hybrid capture-based assays each identified an identical STRN-ALK fusion. Subsequent ALK IHC staining of the same specimens was positive, suggesting that the initial result was a false negative. This report is the first instance of an ALK fusion in CRC detected using a ctDNA assay. KEY POINTS: Current guidelines for colorectal cancer (CRC) only recommend genomic assessment of KRAS, NRAS, BRAF, and microsatellite instability (MSI) status.ALK rearrangements are rare in CRC, but patients with activating ALK fusions have responded to targeted therapiesALK rearrangements can be detected by genomic profiling of ctDNA from blood or tissue, and this methodology may be informative in cases where immunohistochemistry (IHC) or other standard testing is negative.

Randomized Phase II Trial of Parsatuzumab (Anti-EGFL7) or Placebo in Combination with FOLFOX and Bevacizumab for First-Line Metastatic Colorectal Cancer.

LESSONS LEARNED: These negative phase II results for parsatuzumab highlight the challenges of developing an agent intended to enhance the efficacy of vascular endothelial growth factor inhibition without the benefit of validated pharmacodynamic biomarkers or strong predictive biomarker hypotheses.Any further clinical development of anti-EGFL7 is likely to require new mechanistic insights and biomarker development for antiangiogenic agents. BACKGROUND: EGFL7 (epidermal growth factor-like domain 7) is a tumor-enriched vascular extracellular matrix protein that supports endothelial cell survival. This phase II trial evaluated the efficacy of parsatuzumab (also known as MEGF0444A), a humanized anti-EGFL7 IgG1 monoclonal antibody, in combination with modified FOLFOX6 (mFOLFOX6) (folinic acid, 5-fluorouracil, and oxaliplatin) bevacizumab in patients with previously untreated metastatic colorectal cancer (mCRC). METHODS: One-hundred twenty-seven patients were randomly assigned to parsatuzumab, 400 mg, or placebo, in combination with mFOLFOX6 plus bevacizumab, 5 mg/kg. Treatment cycles were repeated every 2 weeks until disease progression or unacceptable toxicity for a maximum of 24 months, with the exception of oxaliplatin, which was administered for up to 8 cycles. RESULTS: The progression-free survival (PFS) hazard ratio was 1.17 (95% confidence interval [CI], 0.71-1.93; p = .548). The median PFS was 12 months for the experimental arm versus 11.9 months for the control arm. The hazard ratio for overall survival was 0.97 (95% CI, 0.46-2.1; p = .943). The overall response rate was 59% in the parsatuzumab arm and 64% in the placebo arm. The adverse event profile was similar in both arms. CONCLUSIONS: There was no evidence of efficacy for the addition of parsatuzumab to the combination of bevacizumab and chemotherapy for first-line mCRC. The Oncologist 2017;22:375-e30.

Phase I Study of CHK1 Inhibitor LY2603618 in Combination with Gemcitabine in Patients with Solid Tumors.

OBJECTIVE: LY2603618, a selective inhibitor of checkpoint kinase 1 (CHK1) and key regulator of the DNA damage checkpoint, may enhance the effects of antimetabolites. This phase I study defined the recommended phase II dose of LY2603618 combined with gemcitabine. PATIENTS AND METHODS: Patients with advanced/metastatic disease were administered doses of LY2603618 (70-250 mg/m2 or flat-fixed doses of 200 or 230 mg) after gemcitabine (1,000 mg/m2). Safety and pharmacokinetics (PK) were assessed. RESULTS: Among the 50 patients enrolled, frequent adverse events possibly related to study drug treatment included fatigue (44%), decreased platelets (42%), decreased neutrophils (32%), nausea (26%), and decreased hemoglobin (20%). Systemic exposure of LY2603618 increased dose dependently, while clearance was relatively dose independent. The mean LY2603618 half-life varied; however, the durations were still suitable for maintaining human exposures while minimizing accumulation. LY2603618 PK were not altered by gemcitabine administration. Plasma exposures that correlate with the maximal pharmacodynamic effect in nonclinical models were achieved for all doses. One patient with non-small cell lung cancer carcinoma achieved a partial response; 22 patients had stable disease. CONCLUSIONS: The maximum tolerated dose of LY2603618 combined with gemcitabine was 200 mg/m2, but a fixed LY2603618 dose of 230 mg combined with gemcitabine was selected as the recommended phase II dose.

Prospective comprehensive genomic profiling of advanced gastric carcinoma cases reveals frequent clinically relevant genomic alterations and new routes for targeted therapies.

BACKGROUND: Gastric cancer (GC) is a major global cancer burden and the second most common cause of global cancer-related deaths. The addition of anti-ERBB2 (HER2) targeted therapy to chemotherapy improves survival for ERBB2-amplified advanced GC patients; however, the majority of GC patients do not harbor this alteration and thus cannot benefit from targeted therapy under current practice paradigms. MATERIALS AND METHODS: Prospective comprehensive genomic profiling of 116 predominantly locally advanced or metastatic (90.0%) gastric cancer cases was performed to identify genomic alterations (GAs) associated with a potential response to targeted therapies approved by the U.S. Food and Drug Administration or targeted therapy-based clinical trials. RESULTS: Overall, 78% of GC cases harbored one clinically relevant GA or more, with the most frequent alterations being found in TP53 (50%), ARID1A (24%), KRAS (16%), CDH1 (15%), CDKN2A (14%), CCND1 (9.5%), ERBB2 (8.5%), PIK3CA (8.6%), MLL2 (6.9%), FGFR2 (6.0%), and MET (6.0%). Receptor tyrosine kinase genomic alterations were detected in 20.6% of cases, primarily ERBB2, FGFR2, and MET amplification, with ERBB2 alterations evenly split between amplifications and base substitutions. Rare BRAF mutations (2.6%) were also observed. One MET-amplified GC patient responded for 5 months to crizotinib, a multitargeted ALK/ROS1/MET inhibitor. CONCLUSION: Comprehensive genomic profiling of GC identifies clinically relevant GAs that suggest benefit from targeted therapy including MET-amplified GC and ERBB2 base substitutions.

An innovative, multi-arm, complete phase 1b study of the novel anti-cancer agent tasisulam in patients with advanced solid tumors.

BACKGROUND: This phase Ib study used a parallel, multi-arm design to examine tasisulam-sodium (hereafter tasisulam), a drug with complex pharmacology, combined with standard chemotherapies in patients with advanced solid tumors, with the ultimate goal of accelerating drug development. METHODS: Patients received escalating doses of tasisulam (3 + 3 schema; target Cmax 300-400 µg/mL) every 28 days plus 1,000 mg/m(2) gemcitabine HCl (days 1 and 15), 60 mg/m(2) docetaxel, 200 mg/m(2)/day temozolomide, 75 mg/m(2) cisplatin, or 150 mg/day erlotinib. Following dose-escalation, patients were enrolled into specific tumor subtype arms, chosen based on the established activity of the standard agent. Because tasisulam is highly albumin-bound, patients in the tumor-specific confirmation arms were dosed targeting specific albumin-corrected exposure ranges (AUCalb) identified during dose-escalation (3,500 h*µg/mL [75th percentile] for docetaxel, temozolomide, and cisplatin; 4,000 h*µg/mL for gemcitabine and erlotinib). RESULTS: A total of 234 patients were enrolled. The safety profile of tasisulam with standard chemotherapies was sufficient to allow enrollment into the dose-confirmation phase in all arms. The primary dose-limiting toxicities were hematologic (thrombocytopenia and neutropenia). The most common grade ≥3 drug-related treatment-emergent adverse event was neutropenia, with the highest incidence in the docetaxel arm. CONCLUSIONS: The multi-arm design allowed the efficient determination of the maximum tolerated dose of tasisulam across multiple combinations, and a preliminary characterization of pharmacokinetics, safety, and potential efficacy. Although enrollment into all planned groups was not completed due to termination of compound development, these data support the feasibility of this approach for accelerated cancer drug development, even for drugs with complex pharmacology.

Results from Phase I Extension Study Assessing Pexidartinib Treatment in Six Cohorts with Solid Tumors including TGCT, and Abnormal CSF1 Transcripts in TGCT.

PURPOSE: To assess the response to pexidartinib treatment in six cohorts of adult patients with advanced, incurable solid tumors associated with colony-stimulating factor 1 receptor (CSF1R) and/or KIT proto-oncogene receptor tyrosine kinase activity. PATIENTS AND METHODS: From this two-part phase I, multicenter study, pexidartinib, a small-molecule tyrosine kinase inhibitor that targets CSF1R, KIT, and FMS-like tyrosine kinase 3 (FLT3), was evaluated in six adult patient cohorts (part 2, extension) with advanced solid tumors associated with dysregulated CSF1R. Adverse events, pharmacokinetics, and tumor responses were assessed for all patients; patients with tenosynovial giant cell tumor (TGCT) were also evaluated for tumor volume score (TVS) and patient-reported outcomes (PRO). CSF1 transcripts and gene expression were explored in TGCT biopsies. RESULTS: Ninety-one patients were treated: TGCT patients (n = 39) had a median treatment duration of 511 days, while other solid tumor patients (n = 52) had a median treatment duration of 56 days. TGCT patients had response rates of 62% (RECIST 1.1) and 56% (TVS) for the full analysis set. PRO assessments for pain showed improvement in patient symptoms, and 76% (19/25) of TGCT tissue biopsy specimens showed evidence of abnormal CSF1 transcripts. Pexidartinib treatment of TGCT resulted in tumor regression and symptomatic benefit in most patients. Pexidartinib toxicity was manageable over the entire study. CONCLUSIONS: These results offer insight into outcome patterns in cancers whose biology suggests use of a CSF1R inhibitor. Pexidartinib results in tumor regression in TGCT patients, providing prolonged control with an acceptable safety profile.

Association of Tumor Mutational Burden and Immune Gene Expression with Response to PD-1 Blockade by Sasanlimab Across Tumor Types and Routes of Administration.

BACKGROUND: Sasanlimab is a monoclonal antibody that binds to the programmed cell death receptor 1 (PD-1). Anti-PD-1 monoclonal antibodies have improved patient clinical outcomes; however, not all treated patients derive clinical benefit. Further insights on potential biomarkers beyond PD-L1 expression levels would help to identify the patients most likely to respond to treatment. OBJECTIVE: This study evaluated tumor biopsies from patients treated with intravenous or subcutaneous sasanlimab to identify biomarkers of response and characterize pharmacodynamic activity. METHODS: Anti-PD-1/PD-ligand 1 (PD-L1)-naive patients with advanced solid tumors received sasanlimab intravenously at 1, 3, or 10 mg/kg every 3 weeks (n = 23) or subcutaneously at 300 mg every 4 weeks (n = 15). Best tumor percentage change from baseline was determined by RECIST. Whole-exome DNA and RNA sequencing were performed in tumor samples collected from treated patients at protocol-defined timepoints. PD-L1 and CD8 protein expression were evaluated in tumor biopsies by immunohistochemistry. Associations with response were assessed by linear regression analysis. RESULTS: Baseline tumor mutational burden (TMB), as well as PD-L1 and CD8 expression, were significantly associated with response to sasanlimab across the multiple dose levels, routes of administration, and range of tumor types evaluated. TMB is an independent biomarker from the various tumor inflammatory genes and signatures evaluated. Gene set enrichment analysis showed that higher baseline expression levels of genes related to the interferon-γ and PD-1 signaling pathways and the cell cycle were significantly associated with response to sasanlimab across tumor types. No differences were observed between routes of administration with regard to response to sasanlimab for the biomarkers of interest (TMB, PD-L1, CD8, and interferon-γ signature). Evaluation of pharmacodynamic changes showed increased tumor expression of genes enriched in adaptive immune response pathways. CONCLUSIONS: Our findings indicate an active, immunomodulatory mechanism for the anti-PD-1 antibody sasanlimab across different tumor types and routes of administration. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02573259; registered October 2015.

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.

A Phase 1b Dose Escalation Trial of NC-6300 (Nanoparticle Epirubicin) in Patients with Advanced Solid Tumors or Advanced, Metastatic, or Unresectable Soft-tissue Sarcoma.

PURPOSE: NC-6300 is a novel nanoparticle formulation of epirubicin that has a pH-sensitive linker conjugated to epirubicin. It exhibits selective tumor accumulation owing to enhanced permeability and retention effect. We conducted a phase 1b trial to determine MTD and recommended phase II dose (RP2D) of NC-6300 monotherapy in advanced, metastatic, or unresectable solid tumors, including soft-tissue sarcomas. PATIENTS AND METHODS: This phase 1b dose-escalation trial of NC-6300 monotherapy employed a Bayesian continuous reassessment method design. NC-6300 was administered on day 1 of every 21-day cycle, with epirubicin-equivalent dose increments from 125 to 215 mg/m2. Safety, efficacy, quality of life, and pharmacokinetic profile of NC-6300 monotherapy were evaluated. RESULTS: Twenty-nine subjects (16 male) were enrolled: 17 with soft-tissue sarcoma, one with osteosarcoma, and 11 with other solid tumors. Observed dose-limiting toxicities included thrombocytopenia, stomatitis, lung infection, and febrile neutropenia. The most common grade 3/4 adverse events were neutropenia (59%), anemia (24%), thrombocytopenia (24%), and febrile neutropenia (21%). MTD and RP2D were determined to be 185 mg/m2 and 150 mg/m2, respectively. The objective response rate in the evaluable population was 11%. Partial response was observed in angiosarcoma and endometrial stromal sarcoma. A dose-dependent increase was observed in both total and released epirubicin concentrations. CONCLUSIONS: NC-6300 was well tolerated with a manageable side effect profile, despite the MTD and RP2D being higher than conventional epirubicin doses. A signal of preliminary activity was observed in angiosarcoma. NC-6300 warrants further investigation in patients with advanced solid tumors, including sarcoma.

Phase I study of epigenetic modulation with 5-azacytidine and valproic acid in patients with advanced cancers.

PURPOSE: 5-Azacytidine (5-AZA) is a DNA-hypomethylating agent. Valproic acid is a histone deacetylase inhibitor. Combining hypomethylating agents and histone deacetylase inhibitors produces synergistic anticancer activity in vitro and in vivo. On the basis of this evidence, we conducted a phase I study of the combination of 5-AZA and valproic acid in patients with advanced cancers. EXPERIMENTAL DESIGN: 5-AZA was administered s.c. daily for 10 days. Valproic acid was given orally daily with a goal to titrate to plasma levels of 75 to 100 mug/mL (therapeutic for seizures). Cycles were 28 days long. 5-AZA was started at 20 mg/m(2) and escalated using an adaptive algorithm based on the toxicity profile in the prior cohort (6 + 6 design). Peripheral blood mononuclear cell global DNA methylation and histone H3 acetylation were estimated with the long interspersed nucleotide elements pyrosequencing assay and Western blots, respectively, on days 1 and 10 of each cycle when patients agreed to provide them. RESULTS: Fifty-five patients were enrolled. Median age was 60 years (range, 12-77 years). The maximum tolerated dose was 75 mg/m(2) of 5-AZA in combination with valproic acid. Dose-limiting toxicities were neutropenic fever and thrombocytopenia, which occurred at a dose of 94 mg/m(2) of 5-AZA. Stable disease lasting 4 to 12 months (median, 6 months) was observed in 14 patients (25%). A significant decrease in global DNA methylation and induction of histone acetylation were observed. CONCLUSION: The combination of 5-AZA and valproic acid is safe at doses up to 75 mg/m(2) for 5-AZA in patients with advanced malignancies.