Safety and anti-tumor activity of lisavanbulin administered as 48-hour infusion in patients with ovarian cancer or recurrent glioblastoma: a phase 2a study

PURPOSE

 Lisavanbulin (BAL101553) is the prodrug of avanbulin (BAL27862), a microtubule-destabilizing agent. The goal of this study (NCT02895360) was to characterize the safety, tolerability and antitumor activity of lisavanbulin administered as a 48-hour intravenous (IV) infusion at the recommended Phase 2 dose (RP2D) of 70 mg/m². Results from the Phase 1 dose-escalation portion of the study identifying the RP2D have been previously reported. Here, we present the findings from the Phase 2a portion of this study. Methods. This multi-center, open-label study included patients with ovarian, fallopian-tube, or primary peritoneal cancer that was either platinum-resistant or refractory (11 patients), or with first recurrence of glioblastoma (12 patients). Lisavanbulin was administered as a 48-hour IV infusion on Days 1, 8, and 15 of a 28-day cycle. Results. Lisavanbulin was well tolerated in both patient cohorts. Thirteen patients (56.5%) developed 49 adverse events assessed as related to study treatment. The majority were mild or moderate; four were grade 3/4. Sixteen SAEs were reported in nine patients (39.1%), with none considered related to study treatment. No AEs led to permanent treatment discontinuation. Three patients in the ovarian cancer cohort had stable disease with lesion size reductions after two cycles of treatment; in the glioblastoma cohort, one patient showed partial response with a > 90% glioblastoma area reduction as best response, and one patient had stable disease after eight cycles of treatment. Conclusion. This study demonstrated a favorable safety and tolerability profile of 48-hour continuous IV infusion of lisavanbulin in patients with solid extracranial tumors or glioblastoma. Clinicaltrials.gov registration: NCT02895360.

Waveguide for air-coupled ultrasonic phased-arrays with propagation time compensation and plug-in assembly

Waveguides allow grating lobe free beamforming for air-coupled ultrasonic phased-arrays by reducing the effective inter-element spacing to half wavelength. Since the sound waves propagate through the waveguide ducts, additional time delays are introduced. In this work, we present analytical, numerical, and experimental methods to estimate these time delays. Afterwards, two different waveguides are compared. The first one consists of equal-length ducts, requiring a time-consuming assembly process of the ultrasonic phased-array. In contrast, the second waveguide consists of Bézier-shaped ducts of unequal lengths but a planar input port allowing fast assembly. The analytical model is based on the geometric lengths of the waveguide ducts. The numerical model relies on a transient finite element analysis. All simulations are validated in an anechoic chamber using a calibrated microphone. The analytical (7.6% deviation) and numerical (3.2% deviation) propagation time models are in good agreement with the measurements. By using the analyzed propagation times for the compensation of the unequal waveguide duct lengths, we restored the beamforming capability without significant sound pressure level (SPL) loss. This work shows the possibility of reduced transducer assembly time for waveguided air-coupled phased-arrays without a reduced SPL.

The potential utility of end-binding protein 1 (EB1) as response-predictive biomarker for lisavanbulin: A phase 2 study of lisavanbulin (BAL101553) in adult patients with recurrent glioblastoma

TPS2068

Background: Lisavanbulin (BAL101553, prodrug of BAL27862) is a novel tumor checkpoint controller that promotes tumor cell death by modulating the spindle assembly checkpoint. BAL27862 is a lipophilic, small molecule (MW 387) shown in rodents to penetrate the brain (1:1 plasma ratio) with promising antitumor activity in orthotopic models of glioblastoma (GB) as monotherapy or in combination with radiotherapy (RT) ± chemotherapy. In a completed phase 1 study (Lopez et al. ESMO 2020, NCT02490800) with daily oral lisavanbulin in patients with recurrent GB or high-grade glioma, the RP2D was determined at 25 mg/day. In this phase 1 study, two patients (out of 20 patients) with GB show a long-lasting (> 2 years) clinical benefit with improvement in clinical symptoms and in target and/or non-target GB lesions as per RANO criteria. Both patients show strong end-binding protein 1 (EB1) expression in their GB tissues as assessed by immunohistochemistry staining. EB1, a protein located on the plus-ends of microtubules, is involved in microtubule (MT) function and has been associated with stemness of glioma cells and a more aggressive disease. Data from GB mouse models suggest that EB1 is a predictive marker for response to lisavanbulin. The prevalence of EB1-positivity in GB is estimated at ̃5%. This ongoing phase 2 study is an extension of the completed Phase 1 study and is conducted to confirm prospectively whether EB1 is a response-predictive biomarker for lisavanbulin in GB. Methods: This is an ongoing multicenter, open-label, phase 2 study using a Simon Two-Stage design to assess the efficacy of lisavanbulin in patients with recurrent GB. The study is being performed in the UK, Switzerland and Germany. Patients with histologically-confirmed GB and recurrent disease after prior RT with alkylating chemotherapy (de-novo/primary GB) or after prior chemotherapy or RT (secondary GB), are eligible for enrollment if their GB archival tumor tissue is EB1-positive. EB1-positivity is defined as moderate to strong EB1-staining in at least 70% of GB tumor cells using a CE-marked immunohistochemistry Clinical Trial Assay (Targos Molecular Pathology GmbH). The primary study objective is the overall response rate by RANO, with MRI scans being performed every 8 weeks. Secondary endpoints include progression-free survival and overall survival. Adverse events are assessed using CTCAEv5. To develop a potential RNA-based response signature, molecular profiling of tumor tissue is performed using whole transcriptome sequencing (RNAseq) in each patient enrolled in the study to define the genomic expression profiles in patients with EB1-positive GB. Nine evaluable patients are to be enrolled in Stage 1, and an additional 10 patients will be enrolled in stage 2 if at least 2 objective responses per RANO criteria are observed in stage 1. Clinical trial information: 02490800.

Expression of end-binding protein 1 (EB1), a potential response-predictive biomarker for lisavanbulin, in glioblastoma and various other solid tumor types

3118

Background: EB1, a protein located on the plus-ends of microtubules is involved in microtubule function and has been associated with glioblastoma (GBM) stem-cell-ness and more aggressive disease. Lisavanbulin (BAL101553) is a prodrug of the lipophilic small molecule BAL27862, that promotes tumor cell death by modulating the spindle assembly checkpoint and has been shown in rodents to efficiently penetrate the brain. Data from GBM mouse models and recent phase 1 clinical data (Lopez et al. ESMO 2020) suggest that EB1 is a response-predictive marker for lisavanbulin in GBM. A phase 2 study is ongoing to confirm this hypothesis (NCT02490800). A proof-of-concept in GBM would support an expansion of EB1-directed lisavanbulin clinical development in non-GBM tumors, which requires prevalence estimates of EB1-positivity in non-GBM tumor types. Methods: Tissue samples from GBM and other tumor types were stained for EB1 using a CE-marked immunohistochemistry Clinical Trial Assay (Targos Molecular Pathology GmbH, Kassel Germany). EB1-positivity was assessed by a board-certified pathologist based on the percentage of tumor cells showing moderate or strong staining for EB1, using thresholds of ≥50%, ≥60% and ≥70% of tumor cells with EB1 positivity. Whole transcriptome sequencing (WTS) using RNAseq was performed in a subset of tissue samples to develop a potential RNA-based predictive response signature for lisavanbulin. Results: 73 GBM tissue samples and 333 tissue samples from 13 other cancer types were stained for EB1. The strongest overall signal for EB1-positivity was obtained for medulloblastoma, neuroblastoma and GBM. In addition, moderate or strong EB1-staining in ≥50% of tumor cells was observed in samples from colorectal cancer (CRC), non small-cell lung cancer (NSCLC), metastatic melanoma, small-cell lung cancer (SCLC) and triple-negative breast cancer (TNBC). An expanded staining campaign is ongoing in these cancer types. Initial results from the ongoing WTS analyses show marked differences in gene expression profiles between EB1-positive and -negative cases. Conclusions: Strong EB1-positivity is infrequent but occurs in a variety of tumor types, with the strongest signals in medulloblastoma, neuroblastoma and GBM. A phase 2 study is ongoing to assess prospectively whether EB1 is a response-predictive biomarker for lisavanbulin in GBM.[Table: see text]

Phase 1/2a trial of intravenous BAL101553, a novel controller of the spindle assembly checkpoint, in advanced solid tumours

BACKGROUND

BAL101553 (lisavanbulin), the lysine prodrug of BAL27862 (avanbulin), exhibits broad anti-proliferative activity in human cancer models refractory to clinically relevant microtubule-targeting agents.

METHODS

This two-part, open-label, phase 1/2a study aimed to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of 2-h infusion of BAL101553 in adults with advanced or recurrent solid tumours. The MTD was determined using a modified accelerated titration design in phase I. Patients received BAL101553 at the MTD and at lower doses in the phase 2a expansion to characterise safety and efficacy and to determine the recommended phase 2 dose (RP2D).

RESULTS

Seventy-three patients received BAL101553 at doses of 15-80 mg/m2 (phase 1, n = 24; phase 2a, n = 49). The MTD was 60 mg/m2; DLTs observed at doses ≥60 mg/m2 were reversible Grade 2-3 gait disturbance with Grade 2 peripheral sensory neuropathy. In phase 2a, asymptomatic myocardial injury was observed at doses ≥45 mg/m2. The RP2D for 2-h intravenous infusion was 30 mg/m2. The overall disease control rate was 26.3% in the efficacy population.

CONCLUSIONS

The RP2D for 2-h infusion of BAL101553 was well tolerated. Dose-limiting neurological and myocardial side effects were consistent with the agent's vascular-disrupting properties.

CLINICAL TRIAL REGISTRATION

EudraCT: 2010-024237-23.

Variability and exposure-response relationships of isavuconazole plasma concentrations in the Phase 3 SECURE trial of patients with invasive mould diseases

Objectives

This analysis evaluated the variability of isavuconazole plasma concentrations between subjects and between sampling times, and assessed their relationship to outcomes for subjects with invasive fungal disease (IFD) in the SECURE trial.

Methods

Isavuconazole-treated subjects received 372 mg of isavuconazonium sulphate (corresponding to 200 mg of isavuconazole) three times daily for 2 days, then once daily. Plasma samples were collected after day 4 and analysis sets were constructed as follows: analysis set 1 included all samples from subjects with proven/probable/possible IFD who received ≥1 dose of isavuconazole; analysis set 2 included samples from subjects in analysis set 1 who had provided >1 sample; and analysis set 3 included samples from subjects in analysis set 1 with proven/probable invasive aspergillosis. Assessments included overall distributions of plasma concentrations and variability between samples (analysis sets 1 and 2) as well as relationships to outcomes [all-cause mortality (day 42), overall response (end of treatment) and treatment-emergent adverse events; analysis sets 1 and 3].

Results

Analysis sets 1, 2 and 3 included samples from 160, 97 and 98 subjects, respectively. Trough concentrations for each were distributed similarly [mean (SD): 3406.6 (1511.5), 3495.6 (1503.3) and 3368.1 (1523.2) ng/mL, respectively]. The mean coefficient of variation between samples in analysis set 2 was 23.2%; differences between concentrations in first samples and subsequent samples were <2-fold for 85/97 subjects. In quartiles of subject data, no concentration-dependent relationships were observed for efficacy or safety.

Conclusions

Plasma concentrations of isavuconazole were reasonably consistent between subjects and sampling times, and were not associated with differences in outcomes.

A Phase 1 study of BAL101553, a novel tumor checkpoint controller targeting microtubules, administered as 48-h infusion in adult patients with advanced solid tumors

Purpose BAL101553, the prodrug of the microtubule-destabilizer BAL27862, previously showed signs of antitumor activity when administered as a 2-h infusion, but its use was limited by vascular toxicity. We investigated an alternative dosing strategy aimed at improving the safety profile of BAL101553. Methods This multicenter, open-label, Phase 1 dose-escalation study used a 3 + 3 design to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), pharmacokinetics, and antitumor activity of BAL101553 administered as a 48-h IV infusion on Days 1, 8, and 15 of a 28-day cycle. Patients received oral BAL101553 on Days 15–21 of cycle 2 to assess oral bioavailability. Results BAL101553 was well tolerated at doses up to ≤70 mg/m². Three grade 3 DLTs occurred: hypotension (70 mg/m²), hyponatremia and neutropenia (both 90 mg/m²). The MTD for 48-h IV BAL101553 was 70 mg/m². At this dose level, the AUC for BAL27862 was 8580 ng.h/mL and the C_max was 144 ng/mL. No apparent dose-related effects on blood pressure were observed with 48-h BAL101553 IV infusion. BAL27862 oral bioavailability was >80%. Conclusions Continuous 48-h IV BAL101553 infusion achieved higher exposure of the BAL27862 active metabolite than a 2-h infusion at the RP2D and did not cause vascular toxicity. Clinicaltrials.gov registration: NCT02895360.

Phase 1/2a study of once daily oral BAL101553, a novel tumor checkpoint controller (TCC), in adult patients with progressive or recurrent glioblastoma (GBM) or high-grade glioma

2025

Background: BAL101553 (prodrug of BAL27862) is a novel TCC that promotes tumor cell death by modulating the spindle assembly checkpoint. BAL27862 is a lipophilic, small molecule shown in rodents to penetrate the brain (brain/plasma ratio around unity), with promising antitumor activity in orthotopic preclinical GBM models as monotherapy or in combination with radiotherapy (RT) with or without temozolomide. In this ongoing study (NCT02490800, CDI-CS-002), daily oral BAL101553 was initially examined in solid-tumor patients, with an MTD of 16 mg/d and DLTs of G4 hyponatremia and G2 hallucinations (Lopez 2018, JCO 36, 2018, suppl. A2530). Subsequently the study was expanded by including a separate cohort of patients with progressive or recurrent GBM or high-grade glioma (Ingles Garces 2017, JCO 35, 2018, suppl. TPS2601). Methods: Patients with histologically-confirmed GBM or high-grade glioma, with progressive or recurrent disease after prior RT with/without chemotherapy, received once-daily oral BAL101553 (28-day cycles) in a 3+3 dose-escalation design to determine the maximum tolerated dose (MTD). Adverse events were assessed by CTCAE v4.03 grade (G), and tumor response by RANO every two cycles. Pharmacokinetics (PK) were evaluated on Day 1 of Cycles 1 and 2. Results: In the ongoing study, 23 pts (13M/10F; median age 50 y), median (min–max) number of prior regimens = 2 (1–5), received doses of 8, 15, 20, 25 or 30 mg oral BAL101553 once daily. One DLT of reversible G2 depression and fatigue occurred at 20 mg. Both mean Cmax and AUC increased with dose between 8 and 30 mg. The PK exposure in GBM patients was lower than for solid tumor patients, in particular at 20 and 25 mg. At 25 mg/d (n = 3), one patient with IDH-mutated GBM had a partial response (63% area reduction per RANO) and continues on study > 8 months, and another patient had stable disease for 5 months. At 15–20 mg/d, stable disease was observed in 3/10 patients. Conclusions: The current data in patients with GBM or high-grade glioma suggest that BAL101553 is well tolerated at dose levels above the MTD established in patients with advanced solid tumors, and shows indications of clinical activity. Clinical trial information: 02490800.

Quantitative evaluation of mechanosensing of cells on dynamically tunable hydrogels

Thin hydrogel films based on an ABA triblock copolymer gelator [where A is pH-sensitive poly(2-(diisopropylamino)ethyl methacrylate) (PDPA) and B is biocompatible poly(2-(methacryloyloxy)ethyl phosphorylcholine) (PMPC)] were used as a stimulus-responsive substrate that allows fine adjustment of the mechanical environment experienced by mouse myoblast cells. The hydrogel film elasticity could be reversibly modulated by a factor of 40 via careful pH adjustment without adversely affecting cell viability. Myoblast cells exhibited pronounced stress fiber formation and flattening on increasing the hydrogel elasticity. As a new tool to evaluate the strength of cell adhesion, we combined a picosecond laser with an inverted microscope and utilized the strong shock wave created by the laser pulse to determine the critical pressure required for cell detachment. Furthermore, we demonstrate that an abrupt jump in the hydrogel elasticity can be utilized to monitor how cells adapt their morphology to changes in their mechanical environment.

Regulation of adhesion behavior of murine macrophage using supported lipid membranes displaying tunable mannose domains

Highly uniform, strongly correlated domains of synthetically designed lipids can be incorporated into supported lipid membranes. The systematic characterization of membranes displaying a variety of domains revealed that the equilibrium size of domains significantly depends on the length of fluorocarbon chains, which can be quantitatively interpreted within the framework of an equivalent dipole model. A mono-dispersive, narrow size distribution of the domains enables us to treat the inter-domain correlations as two-dimensional colloidal crystallization and calculate the potentials of mean force. The obtained results demonstrated that both size and inter-domain correlation can precisely be controlled by the molecular structures. By coupling α-D-mannose to lipid head groups, we studied the adhesion behavior of the murine macrophage (J774A.1) on supported membranes. Specific adhesion and spreading of macrophages showed a clear dependence on the density of functional lipids. The obtained results suggest that such synthetic lipid domains can be used as a defined platform to study how cells sense the size and distribution of functional molecules during adhesion and spreading.

Supplementary motor area activation preceding voluntary movement is detectable with a whole-scalp magnetoencephalography system

Despite the fact that the knowledge about the structure and the function of the supplementary motor area (SMA) is steadily increasing, the role of the SMA in the human brain, e.g., the contribution of the SMA to the Bereitschaftspotential, still remains unclear and controversial. The goal of this study was to contribute further to this discussion by taking advantage of the increased spatial information of a whole-scalp magnetoencephalography (MEG) system enabling us to record the magnetic equivalent of the Bereitschaftspotential 1, the Bereitschaftsfeld 1 (BF 1) or readiness field 1. Five subjects performed a complex, and one subject a simple, finger-tapping task. It was possible to record the BF 1 for all subjects. The first appearance of the BF 1 was in the range of -1.9 to -1.7 s prior to movement onset, except for the subject performing the simple task (-1 s). Analysis of the development of the magnetic field distribution and the channel waveforms showed the beginning of the Bereitschaftsfeld 2 (BF 2) or readiness field 2 at about -0.5 s prior to movement onset. In the time range of BF 1, dipole source analysis localized the source in the SMA only, whereas dipole source analysis containing also the time range of BF 2 resulted in dipole models, including dipoles in the primary motor area. In summary, with a whole-head MEG system, it was possible for the first time to detect SMA activity in healthy subjects with MEG.

A marker for differentiation of capabilities for processing of musical harmonies as detected by magnetoencephalography in musicians

This investigation was designed to study the characteristics of a marker for harmonic processing and to test whether it could be used for differentiating harmonic processing capabilities. The first three chords of an ordinary musical cadenca were presented to the left ear to establish a harmonic context followed by a harmonic or non-harmonic target tone. Cadencas were presented rapidly and randomly in different keys to render the task difficult. Results showed a specific P3m (magnetic P300) effect to the non-harmonic targets which was only visible in subjects with low target recognition errors. Low resolution electro-magnetic tomography current density maps showed P3m sources in the right temporoparietal, left temporoparietal and frontocentral brain areas with right temporoparietal sources being strongest and most reliable. The results offer new possibilities to selectively study harmonic variables in music processing.