Exploiting metabolic acidosis in solid cancers using a tumor-agnostic pH-activatable nanoprobe for fluorescence-guided surgery

Cancer cell metabolism leads to a uniquely acidic microenvironment in solid tumors, but exploiting the labile extracellular pH differences between cancer and normal tissues for clinical use has been challenging. Here we describe the clinical translation of ONM-100, a nanoparticle-based fluorescent imaging agent. This is comprised of an ultra-pH sensitive amphiphilic polymer, conjugated with indocyanine green, which rapidly and irreversibly dissociates to fluoresce in the acidic extracellular tumor microenvironment due to the mechanism of nanoscale macromolecular cooperativity. Primary outcomes were safety, pharmacokinetics and imaging feasilibity of ONM-100. Secondary outcomes were to determine a range of safe doses of ONM-100 for intra-operative imaging using commonly used fluorescence camera systems. In this study (Netherlands National Trial Register #7085), we report that ONM-100 was well tolerated, and four solid tumor types could be visualized both in- and ex vivo in thirty subjects. ONM-100 enables detection of tumor-positive resection margins in 9/9 subjects and four additional otherwise missed occult lesions. Consequently, this pH-activatable optical imaging agent may be clinically beneficial in differentiating previously unexploitable narrow physiologic differences.

It is well known that the pH of tumor tissue is lower than that of the corresponding normal adjacent tissue. Here, the authors report a clinical trial of a pH activatable nanoparticle for imaging tumours.

Abstract CT018: Image guided surgery for tumor agnostic detection of solid tumors using the pH activated micellar imaging agent ONM-100: The Shine study

Introduction: ONM-100, an indocyanine green (ICG) conjugated, micelle-based polymer imaging agent with an exquisitely pH-sensitive binary activation mechanism, may be used for intra-operative tumor detection. Micelles dissociate in acidic environments resulting in fluorescent activation of ICG. As most solid cancer types are acidotic due to anaerobic glycolysis, the so-called Warburg effect, ONM-100 has the potential to act as a tumor agnostic imaging agent targeting a broad range of tumors. This first in-human study investigates the safety and feasibility of ONM-100 as a tumor agnostic imaging agent for intra-operative fluorescent imaging of various solid tumors.

Methods: ONM-100 was IV administered 24±8h prior to surgery in a dose escalation scheme (0.1-1.2mg/kg), and the optimal dose was further evaluated in a subsequent cohort. Patients with histopathologically confirmed breast cancer (BC), head and neck squamous cell carcinoma (HNSCC), colorectal cancer (CRC) and esophageal cancer (EC) were included. Blood was drawn to assess safety and pharmacokinetic data. Intra-operative images were collected before and after tumor excision. After excision, fluorescence images were obtained from serially sliced specimens and formalin fixated paraffin embedded tissue blocks and correlated with standard histopathological assessment.

Results: 30 patients (11 BC, 13 HNSCC, 3 EC, 3 CRC) were enrolled between March and December 2018. No ONM-100 related serious adverse events were observed and the agent was well tolerated at all the dose levels. A strong and sharply demarcated fluorescent signal was observed in all patients with vital tumor tissue (median Contrast to Noise Ratio 3.5; IQR 3.4) which correlated with tumor on final histopathology.

Pharmacokinetics showed increased tumor fluorescence in a dose and plasma concentration-dependent manner. HNSCC, superficially located BC, extraluminal CRC as well as peritoneal metastasis could be clearly visualized in vivo during surgery. In 4 patients (BC and HNSCC), perioperatively, an otherwise unnoticed tumor by the surgeon was detected on the margin or wound bed using fluorescence imaging. Additionally, 2 BC tumor lesions were detected which were missed by conventional pre-operative imaging and pathological assessment.

Conclusion: ONM-100 appears to be safe and allows fluorescent visualization of tumors both in- and ex vivo. The first in-human data demonstrates feasibility for potential use of ONM-100 for image guided surgery, detection of occult disease and margin assessment. Analysis of the microscopic biodistribution of ONM-100 is currently being performed and applications for metastatic lymph node detection will be explored.

Note: This abstract was not presented at the meeting.

Citation Format: Pieter J. Steinkamp, Floris J. Voskuil, Marjory Koller, Bert van der Vegt, Jan J. Doff, Tian Zhao, Jeffrey P. Hartung, Yalia Jayalakshmi, Baran D. Sumer, Jinming Gao, Max J. Witjes, Gooitzen M. van Dam. Image guided surgery for tumor agnostic detection of solid tumors using the pH activated micellar imaging agent ONM-100: The Shine study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT018.

Image-guided surgery for tumor agnostic detection of solid tumors using the pH-activated micellar imaging agent ONM-100

3068

Background: ONM-100, a micelle-based polymer imaging agent conjugated to indocyanine green (ICG) and with an exquisitely pH-sensitive binary activation mechanism, may be used for tumor detection. ONM-100 micelles dissociate in acidic environments resulting in activation of the fluorescent ICG tag. As nearly all solid cancer types are acidotic, ONM-100 has the potential to act as a broadly indicated tumor agnostic imaging agent. This first-in-human study investigates the safety and feasibility of ONM-100 as a tumor agnostic imaging agent for intra-operative fluorescent imaging of various solid tumors. Methods: ONM-100 was IV administered 24±8h prior to surgery in a dose escalation scheme (0.1-1.2mg/kg). Patients with histopathologically confirmed breast cancer (BC), head and neck squamous cell carcinoma (HNSCC), colorectal cancer (CRC) and esophageal cancer (EC) were included. Blood was drawn to assess safety and pharmacokinetic data. Intra-operative fluorescence images were collected before and after tumor excision. Post-excision fluorescence images were obtained from serially sliced specimens and correlated with standard histopathological assessment. Results: 30 patients (11 BC, 13 HNSCC, 3 EC, 3 CRC) were enrolled. No ONM-100 related serious adverse events were observed and the agent was well-tolerated. A strong and sharply demarcated fluorescent signal was observed in all patients with vital tumor tissue (median CNR ranging 1.85-14.05) which correlated with tumor on final histopathology. HNSCC and superficially located BC as well as peritoneal metastasis could be clearly visualized in vivo during surgery. In four patients (BC and HNSCC), perioperatively, tumors otherwise unnoticed by the surgeons were detected on the margin or wound bed using fluorescence imaging. Additionally, two BC tumor lesions were detected that were missed by conventional pre-operative imaging and pathological assessment. Conclusions: ONM-100 appears to be safe and enables fluorescent visualization of tumors both in vivo and ex vivo. The first-in-human data demonstrate the feasibility for potential use of ONM-100 for image guided surgery, margin assessment and detection of occult disease. Clinical trial information: NTR 7085.

Cardiac Safety of Ozanimod, a Novel Sphingosine-1-Phosphate Receptor Modulator: Results of a Thorough QT/QTc Study

Ozanimod is a novel, selective, oral sphingosine-1-phosphate (1 and 5) receptor modulator in development for multiple sclerosis and inflammatory bowel disease. This randomized, double-blind, placebo-controlled, positive-controlled, parallel-group thorough QT study characterized the effects of ozanimod on cardiac repolarization in healthy subjects. Eligible subjects were randomized to 1 of 2 groups: ozanimod (escalated from 0.25 to 2 mg over 14 days) or placebo (for 14 days). A single dose of moxifloxacin 400 mg or placebo was administered on days 2 and 17. The primary end point was the time-matched, placebo-corrected, baseline-adjusted mean QTcF (ΔΔQTcF). A total of 113/124 (91.1%) subjects completed the study. The upper limits of the 2-sided 90% confidence intervals for ΔΔQTcF for both ozanimod 1 and 2 mg were below the 10-millisecond regulatory threshold. No QTcF >480 milliseconds or postdose change in QTcF of >60 milliseconds was observed. There was no evidence of a positive relationship between concentrations of ozanimod and its active metabolites and ΔΔQTcF. Although ozanimod blunted the observed diurnal increase in heart rate, excursions below predose heart rates were no greater than with placebo. Results demonstrate that ozanimod does not prolong the QTc interval or cause clinically significant bradycardia, supporting ozanimod's evolving favorable cardiac safety profile.

Effects of High- and Low-Fat Meals on the Pharmacokinetics of Ozanimod, a Novel Sphingosine-1-Phosphate Receptor Modulator

Ozanimod (RPC1063) is an oral selective modulator of the sphingosine‐1‐phosphate 1 and 5 receptors under development for the treatment of relapsing multiple sclerosis and inflammatory bowel disease. The effects of high‐fat and low‐fat meals on the pharmacokinetics (PK) of a single oral dose of ozanimod were evaluated in 24 healthy volunteers in a randomized, open‐label crossover trial. Each subject received a 1‐mg dose of ozanimod hydrochloride under 3 meal conditions (fasted, high‐fat, and low‐fat), each separated by 7 days. Mean plasma concentration–time profiles for ozanimod and its active metabolites (RP101988 [major], RP101075 [minor]) were similar under all 3 conditions. Moreover, all PK parameters for ozanimod, RP101988, and RP101075 were similar under the 3 meal conditions. The 90% confidence intervals (CIs) for the ratios of geometric least‐squares mean (fed/fasted) were within the equivalence limits of 0.80 to 1.25 for area under the concentration–time curve from time 0 to infinity (AUC_0–∞) and maximum plasma concentration (C_max) for ozanimod, RP101988, and RP101075, except for the high‐fat effect on RP101075 C_max (90%CI, 0.76–0.88). Given this lack of a food effect on the exposure of ozanimod and its active metabolites, ozanimod can be taken without regard to meals.

Results From the First-in-Human Study With Ozanimod, a Novel, Selective Sphingosine-1-Phosphate Receptor Modulator

The sphingosine-1-phosphate 1 receptor (S1P_1R ) is expressed by lymphocytes, dendritic cells, and vascular endothelial cells and plays a role in the regulation of chronic inflammation and lymphocyte egress from peripheral lymphoid organs. Ozanimod is an oral selective modulator of S1P_1R and S1P_5R receptors in clinical development for the treatment of chronic immune-mediated, inflammatory diseases. This first-in-human study characterized the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of ozanimod in 88 healthy volunteers using a range of single and multiple doses (7 and 28 days) and a dose-escalation regimen. Ozanimod was generally well tolerated up to a maximum single dose of 3 mg and multiple doses of 2 mg/d, with no severe adverse events (AEs) and no dose-limiting toxicities. The most common ozanimod-related AEs included headache, somnolence, dizziness, nausea, and fatigue. Ozanimod exhibited linear PK, high steady-state volume of distribution (73-101 L/kg), moderate oral clearance (204-227 L/h), and an elimination half-life of approximately 17 to 21 hours. Ozanimod produced a robust dose-dependent reduction in total peripheral lymphocytes, with a median decrease of 65% to 68% observed after 28 days of dosing at 1 and 1.5 mg/d, respectively. Ozanimod selectivity affected lymphocyte subtypes, causing marked decreases in cells expressing CCR7 and variable decreases in subsets lacking CCR7. A dose-dependent negative chronotropic effect was observed following the first dose, with the dose-escalation regimen attenuating the first-dose negative chronotropic effect. Ozanimod safety, PK, and PD properties support the once-daily regimens under clinical investigation.

Safety and efficacy of the selective sphingosine 1-phosphate receptor modulator ozanimod in relapsing multiple sclerosis (RADIANCE): a randomised, placebo-controlled, phase 2 trial

BACKGROUND

Modulation of sphingosine 1-phosphate (S1P) receptors in a non-selective manner decreases disease activity in patients with multiple sclerosis but has potential safety concerns. We assessed the safety and efficacy of the oral selective S1P receptor modulator ozanimod in patients with relapsing multiple sclerosis.

METHODS

RADIANCE is a combined phase 2/3 trial. Patients with relapsing multiple sclerosis were recruited from 55 academic and private multiple sclerosis clinics in 13 countries across Europe and the USA. Eligible participants were aged 18-55 years, had an Expanded Disability Status Scale (EDSS) score of 0-5·0, and had either one or more relapses in the previous 12 months, or one or more relapses in the past 24 months and one or more gadolinium-enhancing lesions on MRI in the previous 12 months before screening. Participants were assigned by a computer-generated randomisation sequence in a 1:1:1 ratio to ozanimod (0·5 mg or 1 mg) or matching placebo once daily for 24 weeks by an independent, unmasked, statistical team. Trial participants, study site personnel, MRI assessors, steering committee members, and the study statistician were masked to treatment assignment. To attenuate first-dose cardiac effects, ozanimod was up-titrated from 0·25 mg to 0·5 mg or 1 mg over 8 days. The primary endpoint was the cumulative number of total gadolinium-enhancing MRI lesions measured by an independent MRI analysis centre at weeks 12-24 after treatment initiation. Analysis was by intention to treat. Here, we report results from the 24-week phase 2 trial. This trial is registered with ClinicalTrials.gov, number NCT01628393. The 2-year phase 3 trial is ongoing.

FINDINGS

The first patient was randomised on Oct 18, 2012, and the final visit of the last randomised patient was on May 11, 2014. The intention-to-treat and safety population consisted of 258 participants, 88 were assigned placebo, 87 ozanimod 0·5 mg, and 83 ozanimod 1 mg; 252 (98%) patients completed the assigned treatment. The mean cumulative number of gadolinium-enhancing lesions at weeks 12-24 was 11·1 (SD 29·9) with placebo compared with 1·5 (3·7) with ozanimod 0·5 mg (odds ratio 0·16, 95% CI 0·08-0·30; p<0·0001) and 1·5 (3·4) with ozanimod 1 mg (odds ratio 0·11, 95% CI 0·06-0·21; p<0·0001). Three serious adverse events unrelated to treatment were reported in patients assigned ozanimod 0·5 mg: optic neuritis, somatoform autonomic dysfunction, and cervical squamous metaplasia (HPV-related). No serious infectious or cardiac adverse events were reported, and no cases of macular oedema arose. The most common adverse events in the ozanimod 0·5 mg and 1 mg groups compared with placebo were nasopharyngitis (11 and five vs 12), headache (five and three vs eight), and urinary-tract infections (six and two vs two). The maximum reduction in mean heart rate by Holter monitoring during the first 6 h in ozanimod-treated participants was less than 2 beats per min (bpm) compared with baseline, with no patient having a minimum hourly heart rate less than 45 bpm. Electrocardiograms and 24-h Holter monitoring showed no increased incidence of atrioventricular block or sinus pause with ozanimod.

INTERPRETATION

Ozanimod significantly reduced MRI lesion activity in participants with relapsing multiple sclerosis, with a favourable safety profile over a period of 24 weeks. These findings warrant phase 3 trials, which are ongoing.

FUNDING

Receptos, Inc.

Pharmacodynamics, pharmacokinetics, and safety of AM211: a novel and potent antagonist of the prostaglandin D2 receptor type 2

The prostaglandin D(2) receptor type 2 (DP2) and its ligand, PGD(2), have been implicated in the development of asthma and other inflammatory diseases. The authors evaluated the pharmacodynamics, pharmacokinetics and safety of [2'-(3-benzyl-1-ethyl-ureidomethyl)-6-methoxy-4'-trifluoromethyl-biphenyl-3-yl]-acetic acid sodium salt (AM211), a novel and potent DP2 antagonist, in healthy participants. Single and multiple doses of AM211 demonstrated dose-dependent inhibition of eosinophil shape change in blood with near-complete inhibition observed at trough after dosing 200 mg once daily for 7 days. Maximum plasma concentrations and exposures of AM211 increased in a greater-than-dose-proportional manner after single and multiple dosing. After multiple dosing, the exposures on day 7 were higher than on day 1 with accumulation ratio values ranging from 1.4 to 1.5. Mean terminal half-life values ranged from 14 to 25 hours across the dose range of 100 to 600 mg. AM211 was well tolerated at all doses in both the single- and multiple-dose cohorts. These data support additional clinical studies to evaluate AM211 in asthma and other inflammatory diseases.