First-in-human phase Ib trial of M9241 (NHS-IL12) plus avelumab in patients with advanced solid tumors, including dose expansion in patients with advanced urothelial carcinoma.

BACKGROUND: In preclinical studies, combining M9241 (a novel immunocytokine containing interleukin (IL)-12 heterodimers) with avelumab (anti-programmed death ligand 1 antibody) resulted in additive or synergistic antitumor effects. We report dose-escalation and dose-expansion results from the phase Ib JAVELIN IL-12 trial investigating M9241 plus avelumab. METHODS: In the dose-escalation part of JAVELIN IL-12 (NCT02994953), eligible patients had locally advanced or metastatic solid tumors; in the dose-expansion part, eligible patients had locally advanced or metastatic urothelial carcinoma (UC) that had progressed with first-line therapy. Patients received M9241 at 4, 8, 12, or 16.8 µg/kg every 4 weeks (Q4W) plus avelumab 10 mg/kg every 2 weeks (Q2W, dose levels (DLs) 1-4) or M9241 16.8 µg/kg Q4W plus avelumab 800 mg once a week for 12 weeks followed by Q2W (DL5/dose expansion). Primary endpoints for the dose-escalation part were adverse events (AEs) and dose-limiting toxicities (DLTs), and those for the dose-expansion part were confirmed best overall response (BOR) per investigator (Response Evaluation Criteria in Solid Tumors V.1.1) and safety. The dose-expansion part followed a two-stage design; 16 patients were enrolled and treated in stage 1 (single-arm part). A futility analysis based on BOR was planned to determine whether stage 2 (randomized controlled part) would be initiated. RESULTS: At data cut-off, 36 patients had received M9241 plus avelumab in the dose-escalation part. All DLs were well tolerated; one DLT occurred at DL3 (grade 3 autoimmune hepatitis). The maximum-tolerated dose was not reached, and DL5 was declared the recommended phase II dose, considering an observed drug-drug interaction at DL4. Two patients with advanced bladder cancer (DL2 and DL4) had prolonged complete responses. In the dose-expansion part, no objective responses were recorded in the 16 patients with advanced UC; the study failed to meet the criterion (≥3 confirmed objective responses) to initiate stage 2. Any-grade treatment-related AEs occurred in 15 patients (93.8%), including grade ≥3 in 8 (50.0%); no treatment-related deaths occurred. Exposures for avelumab and M9241 concentrations were within expected ranges. CONCLUSIONS: M9241 plus avelumab was well tolerated at all DLs, including the dose-expansion part, with no new safety signals. However, the dose-expansion part did not meet the predefined efficacy criterion to proceed to stage 2.

Genomic amplifications identified by circulating tumor DNA analysis guide prognosis in metastatic castration-resistant prostate cancer.

Purpose: Analysis of circulating tumor DNA (ctDNA) in patients with metastatic prostate cancer (mPC) provides an opportunity to identify and monitor genomic alterations during a patient's treatment course. We evaluated whether the presence of specific gene amplifications (GAs) and plasma copy number (PCN) alterations are associated with disease features. Methods: This is a single-institution retrospective study of patients with mPC who underwent ctDNA profiling using Guardant360® (Guardant Health Inc.). This test identifies single nucleotide variants (SNVs) and GAs of select genes by next-generation sequencing. A total of 155 men with mPC were studied. Patients were stratified by GA status. The Kaplan-Meier method and multivariate cox regression models were used to estimate overall survival (OS) or failure-free survival (FFS) from either the date of GA detection or the initiation of systemic therapy. The chi-square test was used to evaluate associations between clinical factors and GAs. Results: The presence of liver and/or lung metastases was associated with GAs of BRAF, CDK6, PI3KCA, and FGFR1. Survival analyses were completed on a subset of 83 patients with metastatic castration-resistant prostate cancer (mCRPC). Median OS was improved in patients with 1 GA compared to patients with ≥2 GAs, whether determined from the date of initial GA(s) detection (14.9 mo vs. 8.9 mo) or date of therapy initiation nearest to GA detection (16.7 mo vs. 9.0 mo). Patients without GAs had not reached median OS. Patients with androgen receptor (AR) GA only were also found to have better median OS compared to patients with AR GA plus at least one other additional GA (19.3 mo vs. 8.9 mo). Patients with PIK3CA GA had significantly lower median OS compared to patients with GAs that did not have a PIK3CA GA (5.9 mo vs. 16.0 mo). In patients with AR and/or MYC GA(s), median OS improved in those with reduced AR or MYC PCN during therapy compared to those without such a reduction (25.1 mo vs. 15.9 mo). Conclusions: The association of select GAs with survival provides an additional tool for assessing mCRPC prognosis and informing management. Serial monitoring of ctDNA GAs is also useful to guide prognosis and therapeutic response.

Elevated serum CEA is associated with liver metastasis and distinctive circulating tumor DNA alterations in patients with castration-resistant prostate cancer.

BACKGROUND: Elevated serum carcinoembryonic antigen (CEA) is used to identify "treatment emergent" forms of castration-resistant prostate cancer (CRPC) such as aggressive variant prostate cancer (AVPC). However, its individual utility as a prognostic marker and the genetic alterations associated with its expression have not been extensively studied in CRPC. METHODS: This study retrospectively analyzed clinical outcomes and circulating tumor DNA profiles in 163 patients with CRPC and elevated or normal serum CEA. These same patients were then classified as AVPC or non-AVPC and compared to determine the uniqueness of CEA-associated gene alterations. RESULTS: Patients with elevated CEA demonstrated higher rates of liver metastasis (37.5% vs. 19.1%, p = 0.02) and decreased median overall survival from CRPC diagnosis (28.7 vs. 73.2 mo, p < 0.0001). In addition, patients with elevated CEA were more likely to harbor copy number amplifications (CNAs) in AR, PIK3CA, MYC, BRAF, CDK6, MET, CCNE1, KIT, RAF1, and KRAS. Based on variant allele frequency we also defined "clonal" single-nucleotide variants (SNVs) thought to be driving disease progression in each patient and found that CEA expression was negatively correlated with clonal AR SNVs and positively correlated with clonal TP53 SNVs. Of these genetic associations, only the increases in clonal TP53 SNVs and KRAS amplifications were recapitulated among patients with AVPC when compared to patients without AVPC. CONCLUSIONS: Together these findings suggest that CEA expression in CRPC is associated with aggressive clinical behavior and gene alterations distinct from those in AVPC.

Cabozantinib use in metastatic renal cell carcinoma patients in clinical practice: Evaluation of dosing patterns, tolerability, and outcomes compared to clinical trials.

INTRODUCTION: Despite first-line approval in metastatic renal cell carcinoma (mRCC), the tyrosine kinase inhibitor cabozantinib is associated with frequent treatment-limiting side effects. Dose reductions in published trials of the drug and in clinical practice are commonplace. We analyzed our institution's real-world experience with cabozantinib dosing in patients with mRCC to assess strategies to improve tolerability and patient outcomes. OBJECTIVES: The purpose of our study is to retrospectively analyze dose intensity, tolerability, and duration of exposure in mRCC patients who received cabozantinib at our institution. METHODS: In this retrospective, single-center chart review, we identified 35 adult patients who received at least one cycle cabozantinib for mRCC during a two-year period. Dosing patterns were reviewed for each patient to allow calculation of median dose intensity and median duration of exposure. RESULTS: The median dose intensity for cabozantinib was 55.4% and the median actual daily dose was 33.2 mg. Median duration of cabozantinib exposure was 10.4 months. Several alternative dosing strategies were employed with 60% of patients requiring at least one dose intervention to manage toxicities. CONCLUSIONS: Patients in this analysis received a median actual daily dose of 33.4 mg, less than the reported median doses in the METEOR and CABOSUN trials. However, our median duration of cabozantinib treatment was 10.4 months compared to 8.3 months and 6.5 months in these respective trials. Further investigation is warranted to determine if alternative dosing strategies and lower median actual daily doses produce survival results comparable to published clinical trials.

High frequency of rare structural chromosome abnormalities at relapse of cytogenetically normal acute myeloid leukemia with FLT3 internal tandem duplication.

FLT3 internal tandem duplication (ITD) mutations are present in acute myeloid leukemia (AML) in 30% of patients with acute myeloid leukemia (AML), most commonly in those with a normal karyotype, and are associated with short relapse-free survival. Both in vitro and in vivo studies of FLT3-ITD cell lines have demonstrated reactive oxygen species-mediated DNA double-strand breaks and associated error-prone DNA repair as a mechanism of genomic instability, and we hypothesized that genomic instability might be manifested by cytogenetic changes at relapse of FLT3-ITD AML. We retrospectively reviewed charts of patients with cytogenetically normal (CN) FLT3-ITD AML treated at the University of Maryland Greenebaum Cancer Center, with attention to metaphase analysis results at relapse. Cytogenetic data were available from first and, when applicable, subsequent relapses for 15 patients diagnosed with CN FLT3-ITD AML. Among 12 patients with documented FLT3-ITD at first and, when applicable, subsequent relapse, 10 had cytogenetic changes, including nine with rare structural abnormalities. The high frequency of rare structural chromosome abnormalities at relapse in our case series supports a role of genomic instability in the genesis of relapse, and suggests that reactive oxygen species-generating and DNA repair pathways might be therapeutic targets in FLT3-ITD AML.

Ten-day decitabine as initial therapy for newly diagnosed patients with acute myeloid leukemia unfit for intensive chemotherapy.

We retrospectively reviewed outcomes in 45 previously untreated patients with acute myeloid leukemia (AML) considered unfit for chemotherapy who were treated with 10-day courses of decitabine 20 mg/m(2) daily outside of a clinical trial, with no cut-offs for organ function or performance status (PS). Nineteen had Eastern Cooperative Group performance status (ECOG PS) ≥ 2, and 39 had ≥ 2 comorbidities. Fourteen patients (31%) achieved complete remission (CR) and five (11%) CR with incomplete count recovery, for an overall response rate of 42%, after a median of 2 (range, 1-4) courses. The only pretreatment characteristic that differed significantly between responders and non-responders was percent marrow blasts (median 42% vs. 65%; p = 0.01). Median overall survival was 9.0 months; it was 19.4 and 2.3 months for responders and non-responders, respectively (p < 0.001). Thus 10-day decitabine therapy has efficacy in patients with AML considered unfit for chemotherapy, and may serve as a backbone for the addition of other novel agents.