Lawrence Helson

E. coli L‐asparaginase in the treatment of leukemia and solid tumors in 131 children

One hundred thirty‐one children between 1 and 15 years of age have been treated. Ninety‐five children had acute lymphoblastic leukemia (ALL); 13 had other types of leukemia; 8 had lymphoma; and 15 had other solid tumors. The dosage ranged from 10 to 5,000 IU/kg daily. Treatment schedules included maintenance after remission and no maintenance. Nine patients in bone marrow remission with other chemotherapy prior to treatment with A‐ase received a 28‐day course. Six patients received the enzyme intrathecally for meningeal leukemia. Of the 73 adequately treated (over 14 days) ALL patients, the overall remission rate was 62%; the median duration of remission was 60 days with a range of 15 to 248 days. The duration of remission appeared to be independent of dose. Six nonlymphoblastic leukemias demonstrated transient fall in WBC and decreased organ size but no bone marrow remission. One of 4 with Hodgkins disease demonstrated decrease in size of nodes, liver, and spleen. None of the solid tumors responded. The usual side effects of conventional chemotherapeutic agents, mucous membrane ulcerations, alopecia, and diarrhea were not seen. Side effects included reversible abnormal biochemical liver function tests, fever, and anaphylaxis.

Metastasizing extradural ependymoma of the sacrococcygeal region. Case report and review of literature

A case is discussed in which the patient presented with a primary extradural sacrococcygeal ependymoma and synchronous pulmonary metastasis. The clinical course has been characterized by recurrent pulmonary metastases. Management has consisted of repeated surgical resections of the pulmonary metastases and the tumor at the primary site; and the use of a wide spectrum of chemotherapeutic agents. Transplantation of this tumor into nude mice initially resulted in rapid growth but there was spontaneous regression in the second transplants. A general discussion of the management of such lesions is presented, and the literature pertaining to this tumor is discussed.

Safety, tolerability and pharmacokinetics of liposomal curcumin in healthy humans.

INTRODUCTIONnExperimental studies have shown that liposomal curcumin can exert a reduction in tumor growth in pancreatic and colorectal cancer. In this phase I clinical trial we investigated the pharmacokinetics, safety, and tolerability of intravenously administered liposomal curcumin in healthy subjects.nnnMATERIAL AND METHODSn50 male and female participants were included in this randomized, placebo-controlled double-blind phase I dose escalation study. Subjects received a single dose of liposomal curcumin (10 - 400 mg/m2; n = 2 - 6 per group) or placebo over 2 hours intravenously.nnnRESULTSnDose-dependent increases in the plasma concentrations of curcumin and its metabolite tetrahydrocurcumin (THC) were detected. After the end of drug infusion, curcumin and THC plasma concentrations decreased within 6 - 60 minutes below the limit of quantification. Mean urinary excretion was ~ 0.1% of total systemic clearance. Liposomal curcumin was tolerated well, but a transient red blood cell echinocyte formation with concomitant increase in mean cellular volume was observed at dosages ≥ 120 mg/m2.nnnCONCLUSIONnShort-term intravenous dosing of liposomal curcumin appears to be safe up to a dose of 120 mg/m2. Changes in red blood cell morphology may represent a dose limiting sign of toxicity.

Correlation between iodine-131 MIBG imaging and biological markers in advanced neuroblastoma

I-131 metaiodobenzylguanidine (MIBG) imaging was performed in 38 patients with advanced neuroblastoma. Abnormal images were found in patients with elevations of urinary vanillylmandelic acid and dopamine and high serum neuron-specific enolase levels. Normal or minimal elevation of markers was seen in patients with negative images. In follow-up studies after chemotherapy, the disappearance of abnormal uptake was noted in those patients with normal marker values. A persistently abnormal uptake occurred in patients with high marker values. Conversion from a normal image to an abnormal image also occurred in patients whose markers became elevated. I-131 MIBG imaging is sensitive in detecting active foci of a neuroblastoma and is useful in monitoring chemotherapy in these patients.

Use of basic mobile phase to improve chromatography and boost sensitivity for quantifying tetrahydrocurcumin in human plasma by LC–MS/MS

Tetrahydrocurcumin (THC), a major metabolite of curcumin, is often quantified by LC-MS or LC-MS/MS using acidic mobile phases due to the concern of its instability in a basic medium. However, acidic mobile phases often lead to poor chromatography (e.g. split or double peaks) and reduced detection sensitivity in the commonly used negative ionization mode. To overcome these shortcomings, a basic mobile phase was used for the first time in the LC-MS/MS quantification of THC. In comparison with the acidic mobile phases, a single symmetrical chromatographic peak was obtained and the sensitivity increased by 7-fold or more under the equivalent conditions. The new LC-MS/MS method using the basic mobile phase has been successfully validated for the quantification of THC in human EDTA plasma over the concentration range of 5-2500ng/ml. The within-batch accuracy (% nominal concentration) was between 88.7 and 104.9 and the between-batch accuracy ranged from 96.7 to 108.6. The CVs for within- and between-batch precisions were equal to or less than 5.5% and 9.1%, respectively. No significant matrix interference or matrix effect was observed from normal or lipemic and hemolytic plasma matrices. In addition, the common stabilities with adequate durations were established, including up to 5days of post-preparative stability. Furthermore, when the validated method was applied to a clinical study, the passing rate of ISR samples was 83%, indicating the good reproducibility of the method. The success of the unconventional approach presented in this article demonstrates that a mobile phase could be selected based mainly on its merits to facilitate LC separation and/or MS detection. There is no need for excessive concern about the stability of the compound(s) of interest in the selected mobile phase because the run time of modern LC-MS or LC-MS/MS methods is typically only a few minutes.

Mitigating prolonged QT interval in cancer nanodrug development for accelerated clinical translation

BackgroundCardiac toxicity is the foremost reason for drug discontinuation from development to clinical evaluation and post market surveillance [Fung 35:293-317, 2001; Piccini 158:317-326 2009]. The Food and Drug Administration (FDA) has rejected many potential pharmaceutical agents due to QT prolongation effects. Since drug development and FDA approval takes an enormous amount of time, money and effort with high failure rates, there is an increased focus on rescuing drugs that cause QT prolongation. If these otherwise safe and potent drugs were formulated in a unique way so as to mitigate the QT prolongation associated with them, these potent drugs may get FDA approval for clinical use. Rescuing these compounds not only benefit the patients who need them but also require much less time and money thus leading to faster clinical translation. In this study, we chose curcumin as our drug of choice since it has been shown to posses anti-tumor properties against various cancers with limited toxicity. The major limitations with this pharmacologically active drug are (a) its ability to prolong QT by inhibiting the hERG channel and (b) its low bioavailability. In our previous studies, we found that lipids have protective actions against hERG channel inhibition and therefore QT prolongation.ResultsResults of the manual patch clamp assay of HEK 293 cells clearly illustrated that our hybrid nanocurcumin formulation prevented the curcumin induced inhibition of hERG K+ channel at concentrations higher than the therapeutic concentrations of curcumin. Comparing the percent inhibition, the hybrid nanocurcumin limited inhibition to 24.8% at a high curcumin equivalent concentration of 18xa0μM. Liposomal curcumin could only decrease this inhibition upto 30% only at lower curcumin concentration of 6xa0μM but not at 18xa0μM concentration.ConclusionsHere we show a curcumin encapsulated lipopolymeric hybrid nanoparticle formulation which could protect against QT prolongation and also render increased bioavailability and stability thereby overcoming the limitations associated with curcumin.

Non-covalent surface integration: optimising a novel technique for preparing targeted polymeric nanoparticles for cancer therapeutics

Targeting anticancer drugs to their specific molecular targets is a major challenge in cancer therapy. However, advances in biomedical and protein engineering have led to novel nanoparticle targeting approaches. In this study, we used a novel non-covalent insertion of a homo-bifunctional spacer for targeted delivery of drugs to various cancer cells. Functionalised blank nanoparticles for antibody (targeting agent) conjugation were prepared using different cross-linking spacers (bis[sulphosuccinimidyl] suberate (BS3), Disuccinimidyl glutarate (DSG) and sulpho-N-[e-maleimidocaproyloxy] sulphosuccinimide ester (s-EMCS)). The concentration of the spacers and the concentration of antibody used for conjugation were optimised using flow cytometry. The optimised and functionalised nanoparticles thus obtained were characterised for percent yield, mean particle size, surface morphology and percent antibody attachment. Our studies showed the formation of smooth and spherical functionalised poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles which could be successfully conjugated to an antibody, Anti-Annexin A2, for targeting to breast cancer cells. The functionalisation of PLGA nanoparticles for antibody attachment was effectively optimised leading to high percent attachments of 92.8% achieved with BS3. Antibody conjugated PLGA nanoparticles were then evaluated for their targeting potential. Robust intra-cellular uptake of the targeted nanoparticles was observed in breast cancer cell line and in mouse xenograft tumour studies. Our results thus validate that such a novel technique of surface integration may be used for preparing targeted polymeric nanoparticles for cancer therapeutics.

Abstract 2610: Identifying a lead compound for mitigation of drug-induced PQTS

In addition to 170 approved therapeutic drugs whose adverse effects include QT prolongation, a prevalence of 1:2500 subjects in the US are genetically susceptible, or have a diabetic syndrome with increased risk of QT prolongation, torsade de pointes, and sudden death. To address this risk we determined the mitigating effect of a liposome and its components administered intravenously and orally on clinically approved QT-prolonging anticancer drugs, crizotinib and nilotinib, and an antibiotic moxifloxacin (MF) in vitro and in vivo in rats and guinea pigs. Intravenous MF at 20 mg/kg caused a statistically significant QTc prolongation of 35ms in guinea pigs. This observation is in line with peer-reviewed literature in which an oral dose of 400 mg (or approximately 6.1 mg/kg) in humans caused the FDA to black-label MF for causing QT interval prolongation in patients. The mitigating effect of a liposome consisting of dimyristoyl phosphatidylcholine (DMPC) and dimyristoyl phosphatidylglycerol (DMPG) on curcumin, a compound that inhibits the IKr (hERG) current, was initially discovered during preclinical testing with Lipocurc™. Additional patch-clamp studies with DMPC, DMPG, their metabolites myristoyl lysophosphatidylcholine (14:0 LPC) and myristoyl lysophosphatidylglycerol (14:0 LPG), and a synthetic compound, myristoyl ethyleneglycolphosphatidylglycerol (EGPG), revealed mitigation of crizotinib- and nilotinib-induced inhibition of the IKr current. Formulation of 14:0 LPG in a eutectic mixture with a monoglyceride and myristic acid (EU8120) given orally to both normal and diabetic rats prior to challenge with intravenous nilotinib resulted in significantly reduced QT prolongation. We quantified and compared the conduction delays on QT intervals in guinea pigs induced by MF alone with those of MF preceded by oral administration of EU8120, 14:0 LPG, 16:0 LPG, EGPG and DMPG. Three ratios of phospholipids:MF were tested for mitigation of conduction delays: 3:1, 1:1 and 0.3:1. At the 3:1 ratio, all the compounds tested mitigated MF-induced prolongation of QT intervals. While EGPG induced the most protection it caused bradycardia which limited its beneficial effects at that dose level. DMPG was the least potent. At lower ratios of 1:1 and 0.3:1 the mitigating effects of EU8120, EGPG and DMPG were maintained with equal potency. Lipid:MF ratios of 0.1:1 and 0.03:1 are currently being tested and will identify a lead compound for drug development, and offer insight into its mechanism of action. Citation Format: Lawrence Helson, Walter A. Shaw, Stephen W. Burgess, George Shopp, Annie Bouchard, Dany Savail, Muhammed Majeed. Identifying a lead compound for mitigation of drug-induced PQTS. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2610. doi:10.1158/1538-7445.AM2015-2610

Abstract LB-165: Safety and pharmacokinetics of liposomal curcumin in healthy subjects:A randomized placebo-controlled double blind first-in human study.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DCnnPurpose: Curcumin exerts anti-proliferative and pro-apoptotic effects against various tumors in vitro and in vivo, and it has been found to suppress carcinogenesis in various organs. A liposomal curcumin formulation was developed enabling intravenous application.nnMethods: 50 healthy male or female subjects between 18 and 45 years were allocated to receive single ascending doses of liposomal curcumin as a continuous infusion over 120 min. Dose levels ranged from 10 to 400 mg/m2. Within each dose group one subject was randomized to receive placebo. A premedication of intravenous diphenhydramine and dexamethasone or diphenhydramine alone was administered to prevent hypersensitivity reactions. Pharmacokinetic assessments included plasma and urine levels of Curcumin and tetrahydrocurcumin (THC), the active metabolite of Curcumin and were analyzed by a validated LC/MS/MS method. Safety assessments included monitoring for adverse events, laboratory safety parameters with special focus on hemolysis, vital signs and ECG.nnResults and Conclusions: Liposomal curcumin infusions were tolerated without clinical symptoms. At the maximum tolerated dose of 400 mg/m2 of liposomal curcumin, transient increases in erythrocyte mean cell volume, echinocyte formation, and increased plasma lactate were observed. Markers of hemolysis (HBDH, potassium, haptoglobin, LDH, erythrocytes, Hb) did not change significantly, however, a tendency of erythrocyte loss (-0.5 T/l) was observed.nnAt a dose of 120 mg/m2 intermittent echinocyte formation of some erythrocytes was evident. Curcumin and THC levels were established rapidly forming a plateau during infusion with Cmax for curcumin ranging between 42 ± 22 and 2359 ± 412 ng/mL for doses of 10 to 400mg/m2, respectively. Cmax for THC was 7.1 - 15.8-fold lower than Cmax of curcumin. Upon termination of infusion Curcumin and THC were rapidly cleared from plasma with a mean residence time of 0.62 hr for curcumin and 1.69 hr for THC. Urinary curcumin levels accounted for <0.12% of total systemic clearance.Conclusions: Relevant plasma levels of Curcumin were achieved by infusion of liposomal curcumin over 120 min. A continuous infusion (eg 24h) seems appropriate to achieve sustained exposure to curcumin. 120 mg liposomal curcumin/m2 is proposed as safe starting dose for phase I studies in patients with solid tumors.nnCitation Format: Angela Storka, Michael Wolzt, Brigitta Vcelar, Gordon Bolger, Muhammed Majeed, Lawrence Helson. Safety and pharmacokinetics of liposomal curcumin in healthy subjects:A randomized placebo-controlled double blind first-in human study. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-165. doi:10.1158/1538-7445.AM2013-LB-165