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MV-NIS is an oncolytic measles virus encoding the human thyroidal sodium iodide symporter (NIS).Here, we report the results of preclinical pharmacology and toxicology studies conducted in support of our clinical protocol "Phase I Trial of Systemic Administration of Edmonston Strain of Measles Virus, Genetically Engineered to Express NIS, with or without Cyclophosphamide, in Patients with Recurrent or Refractory Multiple Myeloma." Dose-response studies in the KAS-6/1 myeloma xenograft model demonstrated a minimum effective dose of 4 × 10 6 TCID 50 (tissue culture infectious dose 50)/kg. Toxicity studies in measles-naive squirrel monkeys and measles-susceptible transgenic mice were negative at intravenous doses up to 10 8 and 4 × 10 8 TCID 50 /kg, respectively. Abundant viral mRNA, maximal on day 8, was detected in cheek swabs of squirrel monkeys, more so after pretreatment with cyclophosphamide. On the basis of these data, the safe starting dose of MV-NIS for our clinical protocol was set at 1 -2 × 10 4 TCID 50 /kg (10 6 TCID 50 per patient).Measles virus (MV, family Paramyxoviridae) was isolated in 1954 from the throat washings of a measles patient, David Edmonston. 1 Tissue culture passage resulted in loss of pathogenicity and attenuation of wild-type MV (Figure 1), giving rise to the Edmonston measles vaccines used worldwide today. 2 We recently discovered that attenuated Edmonston strain MV has potent antitumor activity in vitro and in vivo. 3 Intravenous, intratumoral, or intraperitoneal administration of the virus inhibited tumor growth or induced tumor regression in a variety of human tumor xenograft models. [4][5][6][7] To tailor the virus for cancer therapy, we Correspondence: SJ Russell (sjr@mayo.edu). CONFLICT OF INTERESTThe authors declared no conflict of interest. NIH Public Access Author ManuscriptClin Pharmacol Ther. Author manuscript; available in PMC 2009 October 28. Published in final edited form as:Clin Pharmacol Ther. 2007 December ; 82(6): 700-710. doi:10.1038/sj.clpt.6100409. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscripthave genetically engineered the viral coat protein to display tumor-targeting ligands to enable tumor-specific killing or inserted trackable transgenes into the viral genome to enable noninvasive monitoring of viral gene expression. [8][9][10][11][12] MV-NIS is an Edmonston-lineage MV that expresses the human sodium iodide symporter (hNIS) (Figure 2). 12 The NIS protein is normally expressed in the thyroid, mammary glands, stomach, and salivary tissue. Expression of NIS allows cells to actively transport iodide ions into the cell. Thus, patients with thyroid cancer are typically treated with 131 I to destroy the NIS-expressing thyroid cancer while leaving most normal tissues undamaged. 13 Loss of thyroid function due to the radiotherapy can be treated by replacement therapy with synthetic thyroid hormones. Insertion of NIS into MV facilitates pharmacokinetic evaluation and enhancement of MV oncolytic activity. MV-NIS-infected cells express...

Abstract1-methyl-D-tryptophan (D-1MT) reverses the immunosuppressive effect of indoleamine 2,3-dioxygenase (IDO), and it is currently being developed both as a vaccine adjuvant and as an immunotherapeutic agent for combination with chemotherapy. The present study examined the pharmacokinetics and toxicity of D-1MT in preparation for clinical trials. Incubation of D-1MT in rat plasma for 24 h produced no significant degradation, with <15% of D-1MT being bound to plasma protein. Following oral administration, D-1MT exhibited a larger AUC and V d , longer elimination t 1/2 , and slower clearance in rats than in dogs. When oral doses of D-1MT exceeded levels of 600 mg/m 2 /day in rats, or 1200 mg/m 2 /day in dogs, the C max and AUC values decreased, resulting in a corresponding decrease in oral bioavailability. Thus, the doses were indicative of the lowest saturating doses in dogs and rats corresponding with an elimination t 1/2 of 6.0 h and 28.7 h, a T max of 1 h and 8 h, and a bioavailability of 47% and 92%, respectively. Tissue concentrations of D-1MT in mice were highest in the kidney, followed by the liver, muscle, heart, lung, and spleen, respectively; 48 h post dosing, D-1MT was excreted in the urine (35.1%) and feces (13.5%). Oral administration of D-1MT in rats from 150 to 3000 mg/m 2 /day (25 to 500 mg/kg/day) and in dogs from 600 to 1200 mg/m 2 /day (30 and 60 mg/kg/day) for 28 consecutive days did not lead to mortality, adverse events, histopathological lesions, or significant changes in hematology, clinical chemistry, and body weight. These results suggested that 3000 and 1200 mg/m 2 /day were the no-observed-adverse-effect levels in rats and dogs, respectively. Mean plasma concentrations of D-1MT (600 and 1200 mg/m 2 /day) in dogs 1 h post dosing were 54.4 and 69.5 μg/ml on Day 1, respectively, and 53.1 and 66.6 μg/ml on Day 28, respectively; thus, indicating no increase in plasma D-1MT with a change in dose. In conclusion, D-1MT has little toxicity when administered orally to rats and dogs. Exceeding the saturating dose of D-1MT is unlikely to cause systemic toxicity, since any further increase in D-1MT plasma levels would be minimal.

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Jaspamide (jasplakinolide; NSC-613009) is a cyclodepsipeptide that has antitumor activity. A narrow margin of safety was observed between doses required for efficacy in mouse tumor models and doses that caused severe acute toxicity in rats and dogs. We explored the hypothesis that the observed toxicity was due to cardiotoxicity. Jaspamide was tested in a patch clamp assay to determine its effect on selected cardiac ion channels. Jaspamide (10 μM) inhibited Kv1.5 activity by 98.5%. Jaspamide also inhibited other channels including Cav1.2, Cav3.2, and HCN2; however, the Kv11.1 (hERG) channel was minimally affected. Using spontaneously contracting human cardiomyocytes derived from induced pluripotent stem cells, effects on cardiomyocyte contraction and viability were also examined. Jaspamide (30 nM to 30 μM) decreased cardiomyocyte cell indices and beat amplitude, putative measurements of cell viability and cardiac contractility, respectively. Concentration-dependent increases in rhythmic beating rate were noted at ≤6 h of treatment, followed by dose-dependent decreases after 6 and 72 hours exposure. The toxic effects of jaspamide were compared with that of the known cardiotoxicant mitoxantrone, and confirmed by multiparameter fluorescence imaging analysis. These results support the hypothesis that the toxicity observed in rats and dogs is due to toxic effects of jaspamide on cardiomyocytes.