A multicenter, open-label, phase 2 study of odetiglucan (IMPRIME PGG) and pembrolizumab in patients with metastatic breast cancer (mBCA) who have progressed through prior hormonal therapy

TPS1115

Background: Hormone receptor (HR) positive/ human epidermal growth factor receptor 2-negative (Her2-) breast cancer is generally considered ‘immunologically cold’ in comparison to TNBC or Her2+ breast cancer. Keynote-028 results showed a modest ORR of 12% to anti-PD1 antibody, pembrolizumab (PEM) in previously treated HR+/ HER2-/programmed death ligand 1-positive (PD-L1-positive) advanced breast cancer patients (pts). With limited options available, there is significant unmet need to expand clinical benefit from ICI. Odetiglucan, a novel beta glucan, acts as a pathogen-associated molecular pattern (PAMP) that drives a cascade of immune activating events. It repolarizes the immunosuppressive microenvironment, activates the maturation of antigen presenting cells and significantly enhances efficacy of ICI therapy in preclinical tumor models. In a Ph2 trial (IMPRIME 1) of odetiglucan + PEM in 44 pts with heavily pretreated metastatic TNBC, an ORR=15.9%, DCR=54.5%, mDOR=12.7mo, mPFS=2.86 mo, 12 mo OS rate=57.6%, and mOS=16.4 mo were observed. Clinical benefit was particularly evident in a subset of pts, mTNBC “converters” (12/44 pts) who were originally diagnosed with ER/PR+ disease and progressed through endocrine therapies +/- CDK4/6 inhibitors. In these 12 pts, an ORR=50%, DCR=83%, mDOR=11.2, mPFS=5.6 mo, 12-mo OS rate=64.8%, and mOS=17.4 mo were observed. Methods: Odetiglucan + PEM is now being explored in pts with hormone-resistant metastatic breast cancer (MBC). This is a phase 2, Simon’s 2-Stage study of MBC pts who have progressed through prior hormonal therapy with >1 CDK4/6 inhibitor. Pts will receive odetiglucan 4 mg/kg/wk + PEM 200 mg Q3wk. Stage 1 will enroll 23 pts. If >4 pts have an objective response after 12 wks of treatment, the study will proceed to Stage 2 enrolling an additional 24 pts (N=47). Rejection of the null hypothesis requires >10 objective responses. Main eligibility criteria include: MBC having failed prior hormonal therapy with >1 CDK4/6 inhibitor, <2 chemotherapies, serum ABA ≥20 µg/mL, and no prior ICI exposure. Primary endpoint is ORR (RECIST v1.1); secondary endpoints are PFS, OS, DCR, DoR, and safety. Exploratory objectives assess impact of the treatment combination on immune activating events in peripheral blood and tumor biopsies, and correlate tumor microenvironmental changes with clinical benefit Select subpopulations may be explored. Point estimates with 95% confidence intervals (CIs) of ORR and DCR will be computed. Medians, first, and third quartiles with 95% CI will be estimated using Kaplan-Meier method for other secondary endpoints. Safety parameters will be summarized. The trial is sponsored by HiberCell, Inc. in collaboration with Merck & Co. ̃25 US sites will participate. Clinical trial information: NCT05159778.

A multicenter, open-label, phase 1a/b study of HC-7366, a modulator of integrated stress response (ISR) kinase GCN2 in subjects with advanced solid tumors

TPS3179

Background: To survive harsh tumor microenvironments, cancer cells actively utilize ISR as an adaptive stress response and survival mechanism. General control nonderepressible 2 (GCN2), a serine-threonine kinase is essential for maintaining cellular homeostasis in amino acid stress conditions. HC-7366 is a novel, highly selective, and potent GCN2 kinase modulator. Single agent HC-7366 has demonstrated potent anti-tumor activity resulting in regression and complete responses in several pre-clinical tumor models. Methods: This is a first in human, multicenter, open label, Phase 1a/b dose escalation and expansion study to establish the maximum tolerated dose, evaluate safety and tolerability, and determine the recommended Phase 2 dose of daily oral dosing of HC-7366 in patients (pts) with advanced solid tumors. Up to 36 pts with squamous cell carcinoma of the head and neck (SCCHN), colorectal cancer (CRC), non-small cell lung cancer (NSCLC), or transitional cell carcinoma of the bladder (TCC) will be enrolled into Phase 1a; other solid tumors are eligible if selection criteria are met (capped at 50%). A 3+3 design will be employed and dose escalation determined by occurrence of dose limiting toxicities (DLT) within Cycle 1 (21 days). A Safety Monitoring Committee will review each cohort when the planned number of pts complete the DLT period. Six dose levels (10, 20, 40, 75, 125, 150 mg) of HC-7366 will be evaluated. Phase 1b will be an expansion of up to two Phase 1a dose levels and enroll 15 pts per cohort. Secondary endpoints include ORR, DOR, TTF, PFS, and OS. Pharmacokinetic data will be profiled. Exploratory objectives include evaluation of pharmacodynamic markers in tumor biopsies and immunophenotyping in blood samples. Main inclusion criteria include: SCCHN, CRC, NSCLC, TCC or other solid tumors; >1 radiologically measurable lesion per RECISTv1.1; >1 biopsiable lesion at baseline; no immune checkpoint inhibitor within 4 weeks (wks) of 1st dose; ECOG 0 or 1; <10% body weight loss in 4 wks before 1st dose & serum albumin >3 g/dL; and normal/adequately controlled pan-endocrine function. Main exclusion criteria include: autoimmune disease, organ transplant, retinitis or photosensitive skin disorders; history of interstitial lung disease or pneumonitis within 1yr; and overt or latent disorders of the exocrine pancreas. Formal hypothesis testing will not be performed. Descriptive statistics of parameters of interest will be presented by dose level and safety parameters will be summarized. The trial is sponsored by HiberCell, Inc. Approximately 9 US sites will participate. Clinical trial information: NCT05121948.

An open label, multicenter phase II study combining imprime PGG (PGG) with pembrolizumab (P) in previously treated metastatic triple-negative breast cancer (mTNBC)

2550

Background: Checkpoint inhibitor (CPI) monotherapy shows limited clinical response in previously treated mTNBC patients (pts) (Table). Agents are needed that extend this benefit to more mTNBC pts. PGG is a novel, IV administered PAMP that, in pts with 20ug/ml anti-beta glucan antibody (ABA+), activates innate immune cells. Preclinically, PGG reprograms myeloid cells to repolarize the immunosuppressive tumor microenvironment & enhance antigen presentation, driving T cell activation- the mechanistic basis to explore PGG + P in mTNBC patients. Methods: 44 mTNBC pts ( 1 line of chemotherapy [Tx] for metastatic disease, ABA) received PGG (4 mpk IV weekly) + P (200 mg IV q3w) until PD or intolerable toxicity. 1° endpoints were ORR by RECIST v1.1 & safety. 2° endpoints included OS & DCR. CT scans (q6 wks) were reviewed locally. Tumor biopsies (pre & 6 wks on Tx) & blood samples were assessed for PGG-mediated immune activation. Results: Table shows IMPRIME 1 clinical response data (Keynote086, PCD4989g shown for context). Confirmed response was also evident in pts with liver or visceral metastases, high LDH. 10 IMPRIME 1 pts were originally ER/PR+, received hormonal Tx and progressed to TNBC. Of these, 5 are confirmed PR, 4 SD (3 still on Tx), 1 PD. No unexpected safety signals were observed. Conclusions: These are the first clinical data to suggest that PGG provides added clinical benefit for pts with previously treated mTNBC and support further development of PGG + P for mTNBC. Clinical trial information: NCT02981303. [Table: see text]

Abstract OT1-01-04: A phase 2, open-label study of imprime PGG (Imprime), a novel beta glucan, with pembrolizumab (Pembro) in chemotherapy-resistant metastatic triple negative breast cancer (TNBC)

By blocking the interaction of PD-L1 with PD-1, immune checkpoint inhibitors (CPI) can unleash specific, anti-cancer killing function of activated cytotoxic T cells in patients (pts) for whom there is evidence of an ongoing anti-cancer immune response (PD-L1 expression and/or activated T cells within the tumor bed). Single agent CPI therapy has provided substantial clinical benefit to pts with multiple cancer types. Though effective, response rates are typically limited (˜15-30% of pts depending on tumor type) and therapy fails to benefit the majority of pts. For these pts there is often limited or no evidence of an ongoing T cell-based immune response. Agents that stimulate the anti-cancer immune response may be particularly promising in expanding the clinical responsiveness to CPI therapies. Imprime is a novel beta glucan derived from Saccharomyces acting mechanistically as a pathogen-associated molecular pattern (PAMP) or non-self danger signal, to awaken and activate the innate immune system. Imprime drives a cascade of immune activating events activating tumor-specific cytotoxic T cells. Imprime treatment elicits repolarization of the immunosuppressive microenvironment while activating the maturation of antigen presenting cells. Imprime has significantly enhanced the efficacy of CPI therapy in preclinical tumor models. In humans, Imprime-mediated innate immune activation requires the formation of an immune complex with naturally-occurring anti-beta glucan antibodies (ABA). Formation of this complex is dependent upon sufficient ABA levels. Imprime is now being studied in combination with pembro (KEYTRUDA®), a humanized mAb against PD-1 which has been previously studied in TNBC pts.This phase 2 study explores the treatment combination in pts with metastatic TNBC who progressed following at least one line of chemotherapy and pts with metastatic melanoma who progressed following CPI therapy with sufficient pre-treatment ABA levels (˜50% of screened patients). The study is a Simon 2-stage design. Specific to the TNBC tumor type, a sample size of 12 pts in Stage 1 is planned. Criteria to advance to Stage 2 are ≤4 GR 3/4 AEs and ≥2 objective responses in TNBC. An additional 30 TNBC pts may be enrolled in Stage 2. Main eligibility criteria are metastatic TNBC after chemotherapy in the metastatic setting and serum ABA ≥20 µg/mL. The primary endpoints are ORR and safety; secondary endpoints are TTR, CRR, DoR, PFS, and OS. Efficacy will be analyzed for ORR and CRR as point estimates with 95% CI and for PFS, OS, DoR and TTR as descriptive summaries. Safety parameters will be summarized. Exploratory endpoints include ORR and PFS based on irRECIST. This study aims to collect pre- and early on-treatment tumor (6 wks post-1st dose) biopsies and peripheral blood to assess the impact of the treatment combination on immune activating events in the periphery and at the tumor site. As of June 2017, 11 sites were open and 4 pts were in treatment. The trial is sponsored by Biothera Pharmaceuticals, Inc. in collaboration with Merck & Co. (ClinicalTrials.gov NCT02981303) For information, contact Richard D. Huhn, MD, Biothera Med Dir at rhuhn@biothera.com or 651-256-4657.

Citation Format: O'Day SJ, Stopeck AT, Huhn RD, Gargano MA, Prathikanti R, Ma B, Mattson PM, Lowe JR, Bose N, Ertelt KE, Ottoson NC, Uhlik MT, Graff JR, Chisamore MJ. A phase 2, open-label study of imprime PGG (Imprime), a novel beta glucan, with pembrolizumab (Pembro) in chemotherapy-resistant metastatic triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-01-04.

Two randomized, double-blind, placebo-controlled, dose-escalation phase 1 studies evaluating BTH1677, a 1, 3-1,6 beta glucan pathogen associated molecular pattern, in healthy volunteer subjects

BACKGROUND

BTH1677 is a beta glucan pathogen associated molecular pattern (PAMP) currently being investigated as a novel cancer therapy. Here, the initial safety and pharmacokinetic (PK) results of BTH1677 in healthy subjects are reported.

SUBJECTS AND METHODS

In the Phase 1a single-dosing study, subjects were randomized (3:1 per cohort) to a single intravenous (i.v.) infusion of BTH1677 at 0.5, 1, 2, 4, or 6 mg/kg or placebo, respectively. In the Phase 1b multi-dosing study, subjects were randomized (3:1 per cohort) to 7 daily i.v. infusions of BTH1677 at 1, 2, or 4 mg/kg or placebo, respectively. Safety and PK non-compartmental analyses were performed.

RESULTS

Thirty-six subjects (N = 24 Phase 1a; N = 12 Phase 1b) were randomized to treatment. No deaths or serious adverse events occurred in either study. Mild or moderate adverse events (AEs) occurred in 67% of BTH1677-treated subjects in both studies. Treatment-related AEs (occurring in ≥10% of subjects) included dyspnea, flushing, headache, nausea, paraesthesia, and rash in Phase 1a and conjunctivitis and headache in Phase 1b. BTH1677 serum concentration was linear with dose. Clearance, serum elimination half-life (t1/2) and volume of distribution (Vss) were BTH1677 dose-independent. In Phase 1b, area under the curve, t1/2, and Vss values were larger at steady state on days 6-30 versus day 0.

CONCLUSIONS

BTH1677 was well tolerated after single doses up to 6 mg/kg and after 7 daily doses up to 4 mg/kg.

A phase 3 open-label, randomized, multicenter study of Imprime PGG in combination with cetuximab in patients with KRAS wild type metastatic colorectal cancer

TPS787

Background: Imprime PGG (Imprime) is a novel immune modulator (complex carbohydrate biologic), which harnesses innate immune cells to enhance killing of antibody-targeted tumor cells. In a phase 2 single-arm clinical trial in mCRC, the combination of Imprime with cetuximab resulted in 24% ORR, 62% disease control rate (DCR), and median time to progression (TTP) of 12 wks (Tamayo ME, Ann Onc 2010), representing approximate 100% increases vs historical control (Cunningham, NEJM 2004). ORR was 45%, DCR, 82% and TTP, 24 wks in pts with KRAS WT tumors (post hoc analysis). Single-agent cetuximab has been shown to improve objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) in patients (pts) with epidermal growth factor receptor (EGFR) expressing, KRAS wild-type (WT) metastatic colorectal cancer (mCRC) who failed oxaliplatin- and irinotecan-based therapy or are intolerant to irinotecan. The mechanism of action of cetuximab is thought to rely on competitive blockade of endogenous ligand binding and downstream signaling, internalization and down regulation of EGFR, as well as antibody-dependent cellular cytotoxicity (ADCC) (Erbitux SmPC). The current trial, sponsored by Biothera (registered with ClinicalTrials.gov NCT01309126) is to confirm these findings in phase 3. Methods: Eligible pts will have had prior oxaliplatin- and irinotecan-based therapy or be intolerant to irinotecan, and will meet key inclusion criteria including measurable disease and ECOG performance status of 0 or 1. In a 2:1 randomization, stratified by geographic region, prior chemotherapy and site, approximately 795 pts will receive weekly open-label Imprime plus cetuximab or cetuximab alone. The primary endpoint of the study is OS and primary analysis will occur when ~709 deaths have occurred. Secondary endpoints include PFS, ORR (based on RECIST 1.1), quality of life, safety and pharmacokinetics. Exploratory endpoints include biomarker analyses. Pt screening and enrollment is underway in the United States and Europe. Clinical trial information: NCT01309126.

Phase Ib study of PGG beta glucan in combination with anti-MUC1 antibody (BTH1704) and gemcitabine for the treatment of advanced pancreatic cancer

TPS493

Background: Mucin 1 (MUC1) is a tumor associated membrane-bound glycoprotein that promotes oncogenesis through promotion of epithelial cell polarity loss, anti-apoptosis, and hypoxia driven angiogenesis. MUC1 overexpression is associated with aggressive behavior and poor outcomes in pancreatic ductal adenocarcinoma (PDAC), and increased resistance to gemcitabine (G) in vitro. BTH1704 (BTH) is a humanized monoclonal antibody (MAb) targeting aberrantly glycosylated MUC1. Imprime PGG (PGG) is a soluble yeast-derived b 1,3/1,6 glucan that binds complement receptor 3 (CR3) on innate immune cells priming them to exert anti-tumor activity against complement (iC3b) opsonized tumor cells. Following incubation of PGG with whole blood from healthy subjects, variability in PGG binding to neutrophils and monocytes has been observed, with higher binding and functional changes correlating with higher levels of endogenous anti-b glucan antibodies. BTH binds to antigens (MUC1), leading to iC3b opsonization of tumor cells thus, allowing PGG-primed leukocytes to kill the iC3b-opsonized tumor cells. This forms the rationale for testing BTH1704 combined with G + PGG. Methods: This is a single institution Phase 1b dose escalation study with a standard 3x3 design to determine the maximal administered dose (MAD) of BTH combined with G + PGG in patients with previously treated advanced PDAC.Each dose cohort includes at least one subject with high and one low PGG binding capability. Primary objectives: establish MAD of BTH combined with G + PGG. Secondary objectives: characterize adverse effects, clinical response, time to progression, progression free and overall survival. Correlative objectives: quantify PGG binding, MDSC phenotyping of PBMC, anti b glucan antibody levels, MUC1 IHC. Inclusion criteria: confirmed advanced PDAC, ECOG PS 0-2, rest period 2-6 weeks from prior first- or second-line treatment. Exclusion criteria: uncontrolled chronic illness. Administration and design: BTH and PGG are administered on days 1, 8, 15, and 22 of a 28-day cycle; G is administered on days 1, 8, and 15. The study is currently enrolling patients. Clinical trial information: NCT02132403. Clinical trial information: NCT02132403.

Determination by HPLC of adrenalin (E) and of noradrenalin (NE) in certain species of mesopelagic fish in the Strait of Messina

The presence of adrenalin (E) and noradrenalin (NE) was found by HPLC both in the photophores and at other tissue levels of numerous species of mesopelagic fish in The Strait of Messina, with the aim of determining the incidence of these catecholamines in photophores, in light transmission and the eventual presence at other tissue levels.

[Bencyclane in memory disorders. Treatment of memory disorders caused by electroshock in a group of depressed patients]

Subjects treated with electroshock and subjected simultaneously to bencyclan at a dose of 00 mg (2 ampoules) i.v. and 100 mg (1 pill) per os pro die did not present dysmnesia either during the intervals between one electroshock treatment and another, nor at the conclusion of treatment (on average 12 sessions in about 40 days), while a control group treated at the same rhythm and with the same number of sessions, but without bencyclan, presented considerable memory lapses which disappeared only after a lengthy period of this latter treatment. Memory disturbances have been evaluated with a memorization test to which all patients were subjected. This test belongs to the group of intellectual efficiency reactive tests used in the psychology laboratory of the Catholic University of Milan; it consists of a group of 12 figures of common objects which, once observed, have to be recalled exactly immediately and some time later by the patient, who has to indicate the name and position of the objects represented in the chart.