Venglustat combined with imiglucerase for neurological disease in adults with Gaucher disease type 3: the LEAP trial.

Gaucher disease type 3 is a chronic neuronopathic disorder with wide-ranging effects, including hepatosplenomegaly, anaemia, thrombocytopenia, skeletal disease and diverse neurological manifestations. Biallelic mutations in GBA1 reduce lysosomal acid ß-glucosidase activity, and its substrates, glucosylceramide and glucosylsphingosine, accumulate. Enzyme replacement therapy and substrate reduction therapy ameliorate systemic features of Gaucher disease, but no therapies are approved for neurological manifestations. Venglustat is an investigational, brain-penetrant, glucosylceramide synthase inhibitor with potential to improve the disease by rebalancing influx of glucosylceramide with impaired lysosomal recycling. The Phase 2, open-label LEAP trial (NCT02843035) evaluated orally administered venglustat 15 mg once-daily in combination with maintenance dose of imiglucerase enzyme replacement therapy during 1 year of treatment in 11 adults with Gaucher disease type 3. Primary endpoints were venglustat safety and tolerability and change in concentration of glucosylceramide and glucosylsphingosine in CSF from baseline to Weeks 26 and 52. Secondary endpoints included change in plasma concentrations of glucosylceramide and glucosylsphingosine, venglustat pharmacokinetics in plasma and CSF, neurologic function, infiltrative lung disease and systemic disease parameters. Exploratory endpoints included changes in brain volume assessed with volumetric MRI using tensor-based morphometry, and resting functional MRI analysis of regional brain activity and connectivity between resting state networks. Mean (SD) plasma venglustat AUC0-24 on Day 1 was 851 (282) ng•h/ml; Cmax of 58.1 (26.4) ng/ml was achieved at a median tmax 2.00 h. After once-daily venglustat, plasma concentrations (4 h post-dose) were higher compared with Day 1, indicating ∼2-fold accumulation. One participant (Patient 9) had low-to-undetectable venglustat exposure at Weeks 26 and 52. Based on mean plasma and CSF venglustat concentrations (excluding Patient 9), steady state appeared to be reached on or before Week 4. Mean (SD) venglustat concentration at Week 52 was 114 (65.8) ng/ml in plasma and 6.14 (3.44) ng/ml in CSF. After 1 year of treatment, median (inter-quartile range) glucosylceramide decreased 78% (72, 84) in plasma and 81% (77, 83) in CSF; median (inter-quartile range) glucosylsphingosine decreased 56% (41, 60) in plasma and 70% (46, 76) in CSF. Ataxia improved slightly in nine patients: mean (SD, range) total modified Scale for Assessment and Rating of Ataxia score decreased from 2.68 [1.54 (0.0 to 5.5)] at baseline to 1.55 [1.88 (0.0 to 5.0)] at Week 52 [mean change: -1.14 (95% CI: -2.06 to -0.21)]. Whole brain volume increased slightly in patients with venglustat exposure and biomarker reduction in CSF (306.7 ± 4253.3 mm3) and declined markedly in Patient 9 (-13894.8 mm3). Functional MRI indicated stronger connectivity at Weeks 26 and 52 relative to baseline between a broadly distributed set of brain regions in patients with venglustat exposure and biomarker reduction but not Patient 9, although neurocognition, assessed by Vineland II, deteriorated in all domains over time, which illustrates disease progression despite the intervention. There were no deaths, serious adverse events or discontinuations. In adults with Gaucher disease type 3 receiving imiglucerase, addition of once-daily venglustat showed acceptable safety and tolerability and preliminary evidence of clinical stability with intriguing but intrinsically inconsistent signals in selected biomarkers, which need to be validated and confirmed in future research.

A phase I dose-escalation study of the safety and pharmacokinetics of a tablet formulation of voxtalisib, a phosphoinositide 3-kinase inhibitor, in patients with solid tumors.

Background Voxtalisib, a PI3K/mTOR inhibitor, has shown antitumor activity in capsule formulation in patients with solid tumors. This Phase I study assessed safety and pharmacokinetics of voxtalisib administered as immediate-release tablets in patients with solid tumors (NCT01596270). Methods A "3 + 3" dose escalation design was used. Adverse events (AEs), pharmacokinetics (PK), food effect and tumor response were evaluated. Results Thirty-two patients received voxtalisib doses ranging from 50 mg to 70 mg once daily (QD) and 17 patients received voxtalisib doses ranging from 30 mg to 50 mg twice daily (BID), for two 28-day cycles. Dose-limiting toxicities (DLTs) were Grade 3 fatigue (two patients at 70 mg QD, one patient at 40 mg BID) and Grade 3 rash (two patients at 50 mg BID). The maximum tolerated dose (MTD) was 60 mg for QD and 40 mg for BID regimens. Common treatment-emergent AEs were diarrhea (41%), nausea (37%) and fatigue (33%). Voxtalisib appeared to follow linear PK, with a general increase in plasma exposure with dose and no significant accumulation. Administration with food caused a slight decrease in exposure; however, given the high variability observed in the exposure parameters, this should be interpreted with caution. Best response was stable disease in 29% and 50% of patients (QD and BID regimens, respectively). Conclusions The safety profile of voxtalisib tablets at the MTD in patients with solid tumors was consistent with that observed with voxtalisib capsules. Given the limited activity observed across multiple clinical trials, no further trials of voxtalisib are planned.

Phase I safety and pharmacokinetic dose-escalation study of pilaralisib polymorph E, a phosphoinositide 3-kinase inhibitor in tablet formulation, in patients with solid tumors or lymphoma.

PURPOSE: Pilaralisib (SAR245408), a pan-class I PI3K inhibitor, has been investigated in Phase I/II trials in several solid tumors and lymphomas in capsule and tablet formulations of polymorph A (capsule-A and tablet-A). This Phase I study was conducted to determine the recommended Phase II dose (RP2D) of a more thermodynamically stable form of pilaralisib (polymorph E), in tablet formulation (tablet-E), in patients with advanced solid tumors or relapsed/refractory lymphoma. METHODS: A modified '3 + 3' dose-escalation design was employed. Patients received pilaralisib once daily (QD; starting dose 400 mg) for two 28-day cycles. Primary endpoints were safety and pharmacokinetics (PK). Exploratory endpoints were pharmacodynamics and efficacy. RESULTS: Eighteen patients were enrolled: Six patients received pilaralisib 400 mg QD and 12 patients received pilaralisib 600 mg QD. Two patients in the 600 mg QD cohort had dose-limiting toxicities (DLTs) (one patient with Grade 3 maculopapular rash and one patient with Grade 3 generalized rash and Grade 4 lipase increased). The most frequently occurring treatment-related, treatment-emergent adverse events were decreased appetite (22 %), dry skin (22 %), nausea (22 %) and vomiting (22 %). In PK analyses, individual exposures observed with 600 mg tablet-E were within the range of data at steady state from previous studies of 400 mg tablet-A and 600 mg capsule-A. Five patients (28 %) had stable disease as best response. CONCLUSIONS: With pilaralisib tablet-E, the RP2D was 600 mg QD, drug exposure was similar to the 400 mg tablet-A and 600 mg capsule-A formulations, and safety was consistent with the known safety profile of pilaralisib.

Phase I study of cabazitaxel plus cisplatin in patients with advanced solid tumors: study to evaluate the impact of cytochrome P450 3A inhibitors (aprepitant, ketoconazole) or inducers (rifampin) on the pharmacokinetics of cabazitaxel.

PURPOSE: Cabazitaxel is primarily metabolized by CYP3A. This study evaluated the impact of moderate/strong CYP3A inhibitors [aprepitant (Study Part 2); ketoconazole (Study Part 3)] or strong CYP3A inducers [rifampin (Study Part 4)] on the pharmacokinetics of cabazitaxel. METHODS: Adult patients received IV cabazitaxel/cisplatin 15/75 mg/m(2) on Day 1 of 3-week cycles (5/75 mg/m(2) in Cycles 1 and 2 of Part 3 to allow a safety margin to the cabazitaxel MTD). Patients received repeated oral doses of aprepitant, ketoconazole or rifampin before/during Cycle 2. Cabazitaxel clearance was the primary endpoint; clearance and area under the plasma concentration-time curve (AUC) were normalized to body surface area and dose, respectively. RESULTS: The PK population included 13 (Part 2), 23 (Part 3) and 21 patients (Part 4). Repeated aprepitant administration did not affect cabazitaxel clearance [geometric mean ratio (GMR) 0.98; 90 % confidence interval (CI) 0.80-1.19]. Repeated ketoconazole administration resulted in 20 % decrease in cabazitaxel clearance (GMR 0.80; 90 % CI 0.55-1.15), associated with 25 % increase in AUC (GMR 1.25; 90 % CI 0.86-1.81). Repeated rifampin administration resulted in 21 % increase in cabazitaxel clearance (GMR 1.21; 90 % CI 0.95-1.53), associated with 17 % decrease in AUC (GMR 0.83; 90 % CI 0.65-1.05). The GMR of AUC0-24 with rifampin administration was 1.09 (90 % CI 0.9-1.33), suggesting that rifampin had a low impact during the initial phases of cabazitaxel elimination. Safety findings were consistent with previous results. CONCLUSIONS: Cabazitaxel pharmacokinetics are modified by drugs strongly affecting CYP3A. Co-administration of cabazitaxel with strong CYP3A inhibitors or inducers should be avoided.

Phase I dose-escalation study of cabazitaxel administered in combination with cisplatin in patients with advanced solid tumors.

INTRODUCTION: Cabazitaxel is a second-generation taxane with in vivo activity against taxane-sensitive and -resistant tumor cell lines and tumor xenografts. Cabazitaxel/cisplatin have therapeutic synergism in tumor-bearing mice, providing a rationale for assessing this combination in patients with solid tumors. METHODS: The primary objectives of this study were to determine dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD) of a cabazitaxel/cisplatin combined regimen (Part 1) and to assess antitumor activity at the MTD (Part 2). Safety and pharmacokinetics (PK) were also examined. RESULTS: Twenty-five patients with advanced solid tumors were enrolled (10 in Part 1; 15 in Part 2). In Part 1, two dose levels were evaluated; the MTD for cabazitaxel/cisplatin (given Q3W) was 15/75 mg/m(2). DLTs occurring during Cycle 1 at the maximum administered dose (20/75 mg/m(2); acute renal failure and febrile neutropenia) and the MTD (febrile neutropenia and hypersensitivity despite pre-medication) were as expected for taxane/platinum combinations. For the 18 patients treated at the MTD, the most frequent possibly related non-hematologic treatment-emergent adverse events (Grade ≥ 3) were nausea (16.7%), fatigue, acute renal failure and decreased appetite (each 11.1%). Neutropenia was the most frequent treatment-emergent Grade ≥ 3 hematologic laboratory abnormality at the MTD (77.8%). The best overall response at the MTD was stable disease, observed in 66.7% of patients. PK results of the combination did not appear to differ from single-agent administration for each agent. CONCLUSION: Combination treatment with cabazitaxel/cisplatin had a manageable safety profile; no PK interactions were evident. The recommended Phase II dose for this combination is cabazitaxel/cisplatin 15/75 mg/m(2) administered every 3 weeks. Antitumor activity findings suggest that further evaluation of this combination in disease-specific trials is warranted.

Local gene transfer and expression following intramuscular administration of FGF-1 plasmid DNA in patients with critical limb ischemia.

NV1FGF is an expression plasmid encoding sp.FGF-1(21-154) currently under investigation for therapeutic angiogenesis in clinical trials. NV1FGF plasmid distribution and transgene expression following intramuscular (IM) injection in patients is unknown. The study involved six patients with chronic critical limb ischemia (CLI) planned to undergo amputation. A total dose of 0.5, 2, or 4 mg NV1FGF was administered as eight IM injections (0.006, 0.25, or 0.5 mg per injection) 3-5 days before amputation. Injected sites (30 cm(3)) were divided into equally sized smaller pieces to assess spatial distribution of NV1FGF sequences (PCR), NV1FGF mRNA (reverse transcriptase-PCR), and fibroblast growth factor-1 (FGF-1)-expressing cells (immunohistochemistry). Data indicated gene expression at all doses. The distribution area was within 5-12 cm for NV1FGF sequences containing the expression cassette, up to 5 cm for NV1FGF mRNA, and up to 3 cm for FGF-1-expressing myofibers. All FGF receptors were detected indicating robust potential for bioactivity after NV1FGF gene transfer. Circulating levels of NV1FGF sequences were shown to decrease within days after injection. Data support demonstration of plasmid-mediated gene transfer and expression in muscles from patients with CLI. FGF-1 expression was shown to be limited to injection sites, which supports the concept of multiple-site injection for therapeutic use.

Gene transfer of a chimeric trans-activator is immunogenic and results in short-lived transgene expression.

Pharmacologic gene regulation is a key technology, necessary to achieve safe, long-term gene transfer. The approaches described in the scientific literature all share in common the creation of artificial transcription factors by fusing a DNA-binding domain, a drug-binding domain and a transcription activation domain. These transcription factors activate the transgene expression upon binding of the pharmacologic agent (antibiotics of the tetracycline family, insect hormone, progesterone antagonist, or immunosuppressor drug) to the drug-binding domain. The major limitations to the use of these systems for human gene and cell therapies are the toxicity of the inducer molecule and the immunogenicity of the chimeric transcription factor. Thus, the gene regulation systems should operate with clinically approved drugs with safety records that do not conflict with the therapeutic gene expression regimen. This work focuses on the characterization of the immunogenicity of a tetracycline-activated transcription factor commonly used in preclinical gene therapy, rtTA2-M2, and its impact on reporter gene expression. We demonstrate that intramuscular injection of plasmid or adenoviral vectors encoding rtTA-M2 in outbred primates generates a cellular and humoral immune response to this transcription factor. The immune response to rtTA2-M2 blunts the duration of the expression the rtTA2-M2-controlled transgene in primates, presumably by destruction of the cells that coexpress rtTA2-M2 and the reporter or therapeutic gene. This immune response may result directly from the vectors used in this study, which prompts the development of new gene transfer vectors enabling safe and efficient pharmacologic gene regulation in clinic.