A Phase 1 Study of Intravenous Plazomicin in Healthy Adults to Assess Potential Effects on the QT/QTc Interval, Safety, and Pharmacokinetics

Plazomicin is an aminoglycoside with in vitro activity against multidrug-resistant Enterobacteriaceae. A phase 1, randomized, double-blind, crossover study assessed the potential effects of plazomicin on cardiac repolarization (NCT01514929). Fifty-six healthy adults (24 men, 32 women) received a single therapeutic dose of plazomicin (15 mg/kg administered by 30-minute intravenous infusion), a single supratherapeutic dose of plazomicin (20 mg/kg administered by 30-minute intravenous infusion), placebo, or oral moxifloxacin (400 mg). The primary end point was the baseline-adjusted, placebo-corrected QTc interval using the Fridericia formula (ΔΔQTcF). Assay sensitivity was concluded if the lower limit of a 1-sided 95%CI (adjusted for multiplicity using the Hochberg procedure) for moxifloxacin ΔΔQTcF was >5 milliseconds at ≥1 prespecified time points. No QT prolongation effect for plazomicin was concluded if the largest mean effect was <5 milliseconds, and the upper limit of a 2-sided 90%CI for plazomicin ΔΔQTcF was <10 milliseconds at all time points. Assay sensitivity was demonstrated based on moxifloxacin ΔΔQTcF. No QT prolongation effect for plazomicin was concluded because the largest mean ΔΔQTcF for plazomicin was 3.5 milliseconds, and the highest upper limit was 5.6 milliseconds. No clinically relevant changes were observed in electrocardiograms. For the 15- and 20-mg/kg dose levels of plazomicin, mean peak plasma concentration values were 76.0 and 96.6 mg/L, and mean values of the area under the concentration-time curve over 24 hours were 263 and 327 mg·h/L, respectively. Model-derived pharmacokinetic parameters and safety findings were generally consistent with previously reported plazomicin studies. In conclusion, therapeutic and supratherapeutic doses of plazomicin had no clinically significant effect on cardiac repolarization and were generally well tolerated.

In vitro and in vivo assessment of the abuse potential of PF614, a novel BIO-MD™ prodrug of oxycodone

OBJECTIVE

The need for pain medication which will not lead to abuse is well recognized. Ensysce has designed prodrug analogs of the commonly used pain medications including hydromorphone, oxycodone (OC), hydrocodone, and morphine that limit their use to oral delivery, two of which are in clinical development. This study was undertaken to demonstrate that PF614, an extended-release prodrug of OC, allows the release of OC as designed when delivered orally, yet it resists ex vivo extraction with household chemicals and is pharmacologically inactive when administered by nonoral routes (nasal and parenteral), thereby substantially reducing its intravenous (IV) and intranasal abuse potential.

METHODS

In vitro and in vivo methods were used to determine release of OC from PF614 and to show potential µ-opioid receptor activity. Plasma and cerebral spinal fluid levels of OC were evaluated following in vivo IV administration of PF614 in rats. In vitro extraction of OC from PF614 was explored using enzymes, common solvents, and household chemicals at room temperature and elevated temperature over time to determine release of OC from the prodrug.

RESULTS

PF614 was stable with in vitro exposure to human plasma, saliva, and liver microsomes or culinary enzyme preparations. PF614 was stable (≥90 percent remaining as intact prodrug) under all room temperature conditions evaluated for 24 hours. At 80°C for 1 hour, no OC was released. Incubation at 80°C for 24 hours in vinegar or vodka produced a conversion to OC of 6 percent. Incubation with trypsin at 37°C converted PF614 approximately stoichiometric to OC with half-life of 4 hours. PF614's penetration of the central nervous system was 83-fold lower than OC and it had a 6.5-fold reduced potency as a µ-opioid agonist. Finally, oral PF614 delivers OC into plasma with an extended-release profile in dogs (reduced C_max; delayed T_max).

CONCLUSIONS

The Bio-Activated Molecular Delivery prodrug design limits the use of PF614 to the intended oral route of delivery with reduced potential for IV or nasal abuse, as it cannot be activated intravenously or nasally to provide an active opioid. Unlike existing opioid formulations, the extended-release profile of PF614 cannot be accelerated by chewing or ex vivo extraction to pharmacologically active substances.

A Phase I-II Trial of Ispinesib, a Kinesin Spindle Protein Inhibitor, Dosed Every Two Weeks as First Line Chemotherapy for Advanced Locally Recurrent or Metastatic Breast Cancer

Background: Kinesin Spindle Protein (KSP) is a mitotic kinesin essential for cell cycle progression. Ispinesib, a selective KSP inhibitor, blocks mitotic spindle assembly with cell cycle arrest in mitosis and subsequent cell death. When dosed on a q21d schedule, the maximum tolerated dose (MTD) was18 mg/m2 and neutropenia was the dose-limiting toxicity (DLT), with nadir at 7-10 d and recovery by d15. Activity was observed in a Phase II trial of ispinesib dosed at 18 mg/m2 q21d in patients (pts) with locally-advanced (LA) or metastatic breast cancer (MBC) after anthracycline and taxane failure (response rate 4/45 [9%]). This trial evaluates safety and efficacy of ispinesib as 1st line chemotherapy (CT) in LA or MBC given on d1 and d15 q28d, which may increase dose density.Methods: This is a multicenter Phase I-II trial. In Phase I, DLT and MTD of ispinesib given d1 and d15 q28d will be determined. Eligibility criteria: LA or MBC; no prior CT except neoadjuvant or adjuvant and ≥ 1 year elapsed since CT; no CNS or leptomeningeal metastases; ECOG 0-1. This is a standard 3+3 dose escalation trial design, starting at 10 mg/m2 and escalating based on tolerability in Cycle (cy) 1. Pharmacokinetic data are collected on d1 and d15 of Cy 1. Phase II of this trial will evaluate efficacy (response rate by RECIST) of ispinesib at the MTD.Results: Phase I of the trial is ongoing. To date, 16 pts were treated at 3 dose levels: 10 (1 cy, n=1; 3 cy, n=1; 6 cy, n=1), 12 (≤1063 cy, n=4; 6 cy, n=1; 10 cy, n=1) and 14 mg/m2 (≤3 cy, n=4; 4 cy, n=2; 12+ cy, n=1). Mean age was 50 yr. 9 pts were Stage IV, 7 Stage IIIB/C; 11 were chemo-naïve; 5 had prior anthracycline and/or taxane; 4 were HER2+ and 5 ER-, PR-, HER2-. The most frequent toxicity was neutropenia: 88% of pts in Cy 1; grade 3/4 in 75%; duration ≤5d; no febrile neutropenia. Diarrhea was reported in 25% and nausea in 19%; all grade 1/2. There was no neuropathy or alopecia. Increased ALT, AST and alkaline phosphatase were reported in 56%, 31% and 19% of pts, respectively. At the 14 mg/m2 dose level, 2/7 pts had DLTs of transient grade 3 AST and ALT increases after Cy 1 d15 dosing; both without increases upon retreatment; 1 pt had liver metastases; neither pt had significant increases in alkaline phosphatase or bilirubin. The 12 mg/m2 cohort was expanded to 6 pts without DLT. There was no cumulative toxicity with continued dosing. 3 pts had partial response, after 1 (n=1) and 4 (n=2) cy, respectively; 1 confirmed by RECIST with duration of 24 weeks; 4 pts had stable disease ≥4 mo.Conclusions: Ispinesib appears to be well tolerated on a q14d dosing schedule at doses tested to date. A dose-density equal to that given in the prior Phase II trial (0.86 mg/m2/d) was tolerated with the q14d schedule with preliminary evidence of efficacy. Further exploration of the 14 mg/m2 dose level and above, as warranted by safety and tolerability, is planned.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6103.

A phase I/II trial of the kinesin spindle protein (KSP) inhibitor SB-743921 dosed q14d without and with prophylactic G-CSF in non-Hodgkin lymphoma (NHL) or Hodgkin lymphoma (HL)

8578

Background: KSP is a mitotic kinesin essential for cell cycle progression. SB-743921 (SB-921), a selective KSP inhibitor, blocks mitotic spindle assembly with cell cycle arrest in mitosis and cell death. In the first-in-humans (FIH) trial, the MTD was 4 mg/m2 q21d. Since neutropenia was the major DLT, with recovery by ∼d15, a q14d schedule without (-GCSF) and with prophylactic G-CSF (+GCSF) is being explored. Methods: In phase I of this phase I/II trial, DLT and MTD of SB-921 given on d1 and d15 q28d (-GCSF) and (+GCSF) will be determined. Eligible patients (pts) have relapsed or refractory HL or NHL, aggressive (a) or indolent (i), have had at least 1 prior chemotherapy (CT) regimen, and have relapsed after or were not candidates for stem cell transplant. This is a standard 3+3 dose escalation trial design, starting at 2 mg/m2 and escalating by 1 mg/m2. Once DLT (-GCSF) is identified, (+GCSF) dosing starts at the (-GCSF) MTD, escalating until (+GCSF) DLT is identified. Results: 39 pts were treated (-GCSF) at 6 dose levels (2–7 mg/m2). 5 pts had DLT: 1/3 at 4 (grade 3 hepatic enzymes; found retrospectively); 2/10 at 6 (both sepsis with neutropenia), and 2/7 at 7 (both grade 4 neutropenia lasting >5d) mg/m2. MTD (-GCSF) was 6 mg/m2. 12 pts were treated with SB-921 (+GCSF) at 6 (n=4), 7 (n=3), 8 (n=3) and 9 (n=2) mg/m2, with 1 DLT of neutropenia at 9 mg/m2. Expansion of the 9 mg/m2 (+GCSF) cohort to n=6 is ongoing. For all 51 pts treated to date, mean age was 52 yr; 53% were male; 39% HL, 33% aNHL, and 28% iNHL; 76% had ≥3 prior CT regimens. The most frequent grade 3/4 toxicity was neutropenia: 58% at ≥MTD (-GCSF) and 42% (+GCSF). Other grade 3/4 events were uncommon. There was no neuropathy or alopecia >grade 1. There were 2 partial responses (PR), both in elderly pts with HL with ≥2 prior CT regimens, 1 at 6 (-GCSF) and 1 at 8 (+GCSF) mg/m2, ongoing at Cycle 4+. Conclusions: The MTD of SB-921 (-GCSF) on a q14d schedule was 6 mg/m2. This dose density (0.43 mg/m2/d) is >2-fold higher than in the FIH trial with a q21d schedule (0.19 mg/m2/d). Dose escalation (+GCSF) is continuing. SB-921 is well tolerated with minimal toxicity other than hematologic. Activity has been observed in HL, with 2 PRs at doses ≥6 mg/m2.

[Table: see text]

A phase I/II trial of ispinesib, a kinesin spindle protein (KSP) inhibitor, dosed q14d in patients with advanced breast cancer previously untreated with chemotherapy for metastatic disease or recurrence

1077

Background: KSP is a mitotic kinesin essential for cell cycle progression. Ispinesib, a selective KSP inhibitor, blocks mitotic spindle assembly with cell cycle arrest in mitosis and subsequent cell death. On a q21d schedule, the MTD was 18 mg/m2. In a phase II trial of ispinesib dosed at 18 mg/m2 q21d in patients (pts) with advanced breast cancer after anthracycline and taxane failure, the response rate was 4/45 (9%). This trial evaluates ispinesib given on d1 and d15 q28d, thus increasing dose density. Methods: In phase I of this phase I/II trial, DLT and MTD of ispinesib given d1 and d15 q28d will be determined. Eligibility criteria: advanced breast cancer; no prior chemotherapy (CT) except neoadjuvant or adjuvant and ≥ 1 yr elapsed since CT; no CNS metastases; ECOG 0–1. This is a standard 3+3 dose escalation trial design, starting at 10 mg/m2 and escalating based on tolerability in cycle (cy) 1. Pharmacokinetic data are collected in cy 1. Results: Phase I of the trial is ongoing. 16 pts were treated at 3 dose levels: 10 (n = 3), 12 (n = 6), and 14 mg/m2 (n = 7). 9 pts were stage IV; 11 were chemo-naïve; 5 had prior anthracycline and/or taxane; 4 were HER-2+ and 5 ER-, PR-, HER-2-. The most frequent toxicity was neutropenia. 88% of pts in cy 1 (grade 3/4 in 75%; no febrile neutropenia). Mild GI toxicity occurred in <37.5% of pts. There was no neuropathy or alopecia. At the 14 mg/m2 dose level, 2/7 pts had DLTs of transient grade 3 AST and ALT increases after cy 1 d15 dosing; both without increases upon retreatment; 1 in a pt with liver metastases; neither pt had significant increases in alkaline phosphatase or bilirubin. The 12 mg/m2 cohort was expanded to 6 pts without DLT. 3 pts had partial response (after 1 [n = 1] and 4 [n = 2] cy, respectively); 1 confirmed and ongoing after 8+ cy; 4 pts had stable disease ≥4 mo. Conclusions: Ispinesib appears to be well tolerated on a q14d dosing schedule at doses tested to date. A dose-density equal to that given in the prior phase II trial (0.86 mg/m2/d) was tolerated with the q14d schedule with preliminary evidence of efficacy. Further exploration of the 14 mg/m2 dose level is planned.

[Table: see text]

A phase I-II trial of Ispinesib, a kinesin spindle protein inhibitor, dosed every two weeks in patients with locally advanced or metastatic breast cancer previously untreated with chemotherapy for metastatic disease or recurrence

Abstract #2148

Kinesin Spindle Protein (KSP) is a mitotic kinesin essential for cell cycle progression. Ispinesib, a selective KSP inhibitor, blocks mitotic spindle assembly with cell cycle arrest in mitosis and subsequent cell death. When dosed on a q21d schedule, the maximum tolerated dose (MTD) was 18mg/m2 and neutropenia was the dose-limiting toxicity (DLT), with nadir at 7-10 d and recovery by d15. Activity was observed in a Phase II trial of ispinesib dosed at 18 mg/m2 q21d in patients (pts) with locally-advanced (LA) or metastatic breast cancer (MBC) after anthracycline and taxane failure (response rate 4/45 [9%]). This trial evaluates safety and efficacy of ispinesib in LA or MBC, given on d1 and d15 q28d, thus increasing dose density.&#x2028; Methods: This is a multicenter Phase I-II trial. In Phase I, DLT and MTD of ispinesib given d1 and d15 q28d will be determined. Eligibility criteria: LA or MBC; no prior chemotherapy (CT) except neoadjuvant or adjuvant and ≥ 1 year elapsed since CT; no CNS or leptomeningeal metastases; ECOG 0-1. This is a standard 3+3 dose escalation trial design, starting at 10 mg/m2 and escalating based on tolerability in Cycle 1. Pharmacokinetic data are collected on d1 and d15 of Cycle 1. Phase II of this trial will evaluate efficacy (response rate by RECIST) of ispinesib at the MTD.&#x2028; Results: Phase I of the trial is ongoing. To date, 13 pts have been treated at 3 dose levels: 10 (n=2; 2 cycles, n=1; 6 cycles), 12 (n=1; 1 cycle, n=2; 3 cycles) and 14 mg/m2 (n=7; Cycle 1 ongoing). Among the first 6 pts, 4 were Stage IV, 3 had prior neoadjuvant and 2 adjuvant CT; 2 were chemo-naïve. Four had prior anthracycline and 3 prior taxane. Biomarker status was ER+, PR+, HER2- (n=3), ER+, PR-, HER2- (n=1), ER-, PR-, HER2+ (n=3), ER-, PR-, HER2- (n=4), and unknown (n=2). Mean age was 55 yr; for the first 2 dose levels (n=6 pts), the most frequent toxicity was neutropenia (n=4). Other events included mild GI toxicity. No neuropathy or alopecia has been reported. The only grade 3 or 4 toxicity was neutropenia (n=2). At the 14 mg/m2 dose level, one DLT has been reported: a grade 3 transaminase (AST) elevation in a patient with liver metastases which resolved with a dose delay of 4 days. As a result, this cohort was expanded to include 6 evaluable pts. One additional patient at the 14mg/m2 dose had a dose delay of 5 days due to non-DLT neutropenia.&#x2028; Conclusions: Ispinesib appears to be well tolerated on a q2w dosing schedule at doses tested to date. A dose-density equal to that administered in the prior Phase II trial (0.86 mg/m2/day) was tolerated with the new q2w schedule. Dose escalation is ongoing.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2148.

Tissue penetration of telavancin after intravenous administration in healthy subjects

The pharmacokinetic disposition of telavancin administered 7.5 mg/kg of body weight every 24 h was determined in plasma and skin blister fluid. The mean penetration of telavancin into blister fluid was 40%. This study reveals that adequate concentrations are achieved in both plasma and blister fluid for pathogens frequently implicated in skin and soft tissue infections.

Pharmacokinetics, serum inhibitory and bactericidal activity, and safety of telavancin in healthy subjects

The pharmacokinetics, tolerability, and serum inhibitory and bactericidal titers of telavancin, a new rapidly bactericidal lipoglycopeptide with multiple mechanisms of action against gram-positive pathogens, were assessed in a two-part, randomized, double-blind, placebo-controlled, ascending-dose study with 54 healthy men. In part 1, single ascending intravenous doses of 0.25 to 15 mg/kg of body weight were studied. In part 2, multiple ascending doses (30-min infusions of 7.5 to 15 mg/kg/day) were studied over 7 days. Following the administration of multiple doses, steady state was achieved by days 3 to 4. At day 7 after the administration of telavancin at 7.5, 12.5, and 15 mg/kg/day, peak concentrations in plasma were 96.7, 151.3, and 202.5 microg/ml, respectively, and steady-state area-under-the-curve values were 700, 1,033, and 1,165 microg x h/ml, respectively. The elimination half-life ranged from 6.9 to 9.1 h following the administration of doses > or =5 mg/kg. Most adverse events were mild in severity. At 24 h postinfusion, serum from subjects given telavancin demonstrated potent bactericidal activity against methicillin-resistant Staphylococcus aureus and penicillin-resistant Streptococcus pneumoniae strains. The results suggest that telavancin may be an effective once-daily therapy for serious bacterial infections caused by these pathogens.

Spirocyclic nonpeptide glycoprotein IIb-IIIa antagonists. Part 1: design of potent and specific 3,9-diazaspiro[5.5]undecanes

The synthesis and biological activity of novel glycoprotein IIb-IIla antagonists containing the 3,9-diazaspiro[5.5]undecane nucleus are described. The potent activity of these compounds as platelet aggregation inhibitors demonstrates the utility of the spirocyclic structures as a central template for nonpeptide RGD mimics.

Spirocyclic nonpeptide glycoprotein IIb-IIIa antagonists. Part 2: design of potent antagonists containing the 3-azaspiro[5.5]undecanes

The synthesis and biological activity of novel glycoprotein IIb-IlIa anatagonists containing 3-azaspiro[5.5]undec-9-yl nucleus are described. The potent activity of these compounds as platelet aggregation inhibitors demonstrates the utility of the monoazaspirocyclic structure as central template for nonpeptide RGD mimics.