Dwight R. Stickney

Safety and Activity of the Immune Modulator HE2000 on the Incidence of Tuberculosis and Other Opportunistic Infections in AIDS Patients

ABSTRACT Twenty-five AIDS patients were treated with HE2000, a synthetic adrenal hormone. The drug was well tolerated and safe and reduced both the incidence of tuberculosis coinfection by 42.2% (P < 0.05) and the cumulative incidence of opportunistic infections (P < 0.05). These results warrant further clinical investigation of HE2000.

Enhancement of immune status by high levels of dietary vitamin B‐6 without growth inhibition of human malignant melanoma in athymic nude mice

The effects of dietary vitamin B-6 supplementation on the development of human malignant melanoma (M21-HPB) xenografts and on in vitro responses of leukocytes were examined. Male athymic nude mice, five weeks old, were divided into two groups of 48 each and fed 20% casein diets containing pyridoxine (PN) at 4.1 (control diet) and 61.6 mg/kg diet for 10 weeks. After four weeks of dietary treatment, 20 animals from each dietary group were injected subcutaneously with 3 x 10(7) melanoma cells. After 4, 8, and 10 weeks of dietary regimen, animals from each group were killed and blood, liver, and spleen samples were obtained. Food consumption and mouse body weights were similar between groups, and no difference was noted in tumor incidence or volume. Noninjected and tumor-bearing mice given the PN 61.6 diet generally exhibited greater oxygen radical production by phagocytic cells from blood and spleen than did animals fed the PN 4.1 diet. Spleen and blood B lymphocyte proliferation in response to lipopolysaccharide (LPS) was enhanced (10 and 30%) in the noninjected animals given the PN 61.6 diet. In addition, tumor-bearing mice fed the PN 61.6 diet had significantly greater LPS-induced spleen cell proliferation at eight weeks when compared with mice consuming the PN 4.1 diet. Despite immune enhancement, tumor incidence and progression was not modified by a high level of dietary vitamin B-6. Therefore, it is tempting to speculate that tumor inhibition by high dietary vitamin B-6 may be mediated by T lymphocyte-dependent mechanisms that are lacking in these genetically immuno-deficient mice.

A synthetic anti-inflammatory sterol improves insulin sensitivity in insulin-resistant obese impaired glucose tolerance subjects

To study the activity of HE3286 (17α‐ethynylandrost‐5‐ene‐3β,7β,17β‐triol), an anti‐inflammatory sterol that is active in models of obesity‐induced inflammation and insulin resistance in high body mass index (BMI) subjects with impaired glucose tolerance (IGT).

Effect of pyridoxine and pyridoxal on the in vitro growth of human and murine cancer cells

Abstract Previous work conducted in our laboratories, using a murine model, suggested that the consumption of high levels of vitamin B-6 [pyridoxine (PN)] may suppress tumor development either by immune enhancement or by pyridoxal 5′-phosphate (PLP) growth regulation. To explore this relationship further, we assessed the effects of PN and pyridoxal (PL) on the growth of human (MCF-7, mammary; DU-145, prostate; CAKI-1, renal) and mouse (H238, fibrosarcoma) cancer cell lines. The incubation of cancer cells for 3 (H238) to 20 (MCF-7, DU-145, CAKI-1) days in culture media supplemented with high doses of PN (2.5–5.0 mM) or PL (0.05–5.0 mM) showed significant reductions in proliferation (13% to 100%) as compared to control cultures. PL was more efficacious than PN as a cytotoxin. Cell mortality was observed in a dose-dependent manner, but sensitivity to PN and PL at concentrations approximating physiologic levels (0.005 mM) did not retard growth. Intracellular levels of PL and PLP were significantly elevated in H238 cultures exposed to pharmacologic, but not physiologic concentrations of PN and PL. MCF-7, DU-145, CAKI-1, and H238 cells cultured for 3 h in media supplemented with 0.5 mM PL and labeled with [ 3 H] precursors generally incorporated significantly less leucine, uridine, and thymidine into TCA-precipitable material than did control cultures. In contrast, cells supplemented with 0.005 mM PL showed no inhibition in incorporation. The results indicate that physiological concentrations of PN and PL may not be directly cytotoxic to human or animal cancer cells in vivo .

In vivo and in vitro stimulation of cell-mediated immunity by vitamin B-6

Abstract The effects of vitamin B-6 supplementation and deficiency on responses relating to cell-mediated immunity were studied. Male BALB/cByJ mice (n=80), 5 weeks of age, were fed 20% casein diets containing pyridoxine (PN) at 0.2, 1.2 (control diet), 7.7, or 74.3 mg/kg diet. After 7 weeks of dietary treatment, mice fed the diets supplemented with PN 7.7 or PN 74.3 exhibited 29% and 27% greater footpad swelling after challenge with purified protein derivative (PPD) when compared to the PN 1.2 diet group (p

17α-Alkynyl 3α, 17β-androstanediol non-clinical and clinical pharmacology, pharmacokinetics and metabolism

Summary17α-ethynyl-5α-androstane-3α, 17β-diol (HE3235, Apoptone) is an orally bioavailable synthetic analogue of 3β-androstanediol, that is active in rodent models of prostate and breast cancer, and is in Phase IIa clinical trials for the treatment of early- and late-stage prostate cancer. In preparation for clinical studies, nuclear hormone receptor and P450 interactions for HE3235 and major metabolites were characterized in vitro, and pharmacokinetics and metabolite profiles were studied in rodents, dogs, and monkeys. Four-week safety studies conducted in rats and dogs indicated a substantial margin of safety for clinical use, and no evidence of electrocardiographic or neurological effects, although anorexia, thrombocytopenia, and hypokalemia were identified as potentially dose-limiting toxicities at superpharmacological exposures. Pharmacokinetics and drug metabolism have been studied in prostate cancer patients.

5-Androstene-3β,17β-diol Promotes Recovery of Immature Hematopoietic Cells Following Myelosuppressive Radiation and Synergizes With Thrombopoietin

PURPOSE 5-Androstene-3β,17β-diol (5-AED) stimulates recovery of hematopoiesis after exposure to radiation. To elucidate its cellular targets, the effects of 5-AED alone and in combination with (pegylated) granulocyte colony-stimulating factor and thrombopoietin (TPO) on immature hematopoietic progenitor cells were evaluated following total body irradiation. METHODS AND MATERIALS BALB/c mice were exposed to radiation delivered as a single or as a fractionated dose, and recovery of bone marrow progenitors and peripheral blood parameters was assessed. RESULTS BALB/c mice treated with 5-AED displayed accelerated multilineage blood cell recovery and elevated bone marrow (BM) cellularity and numbers of progenitor cells. The spleen colony-forming unit (CFU-S) assay, representing the life-saving short-term repopulating cells in BM of irradiated donor mice revealed that combined treatment with 5-AED plus TPO resulted in a 20.1-fold increase in CFU-S relative to that of placebo controls, and a 3.7 and 3.1-fold increase in comparison to 5-AED and TPO, whereas no effect was seen of Peg-G-CSF with or without 5-AED. Contrary to TPO, 5-AED also stimulated reconstitution of the more immature marrow repopulating (MRA) cells. CONCLUSIONS 5-AED potently counteracts the hematopoietic effects of radiation-induced myelosuppression and promotes multilineage reconstitution by stimulating immature bone marrow cells in a pattern distinct from, but synergistic with TPO.

An Anti-Inflammatory Sterol Decreases Obesity-Related Inflammation-Induced Insulin Resistance and Metabolic Dysregulation

Obesity-related inflammation-induced insulin resistance and metabolic dysregulation were investigated in retrospective analysis of placebo hematologic and metabolic laboratory data from trials associated with increasing chronic low-grade inflammation and body mass index. Studies included healthy subjects and those with progressive stages of metabolic dysregulation, including type 2 diabetes mellitus with uncontrolled hemoglobin A1c. Intrasubject variances in erythroid and metabolic values increased with metabolic dysregulation. Random effects were demonstrated in treatment-naïve diabetes for erythroid, glucose, and HbA1c fluctuations. The anti-inflammatory insulin sensitizer, HE3286, was tested for its ability to decrease obesity-related inflammation-induced insulin resistance and metabolic dysregulation in diabetes. HE3286 significantly decreased erythroid and metabolic variances and improved 1,5-anhydroglucitol (a surrogate of postprandial glucose) compared to the placebo group. HE3286 HbA1c decrease correlated with weight loss and inversely with baseline monocyte chemoattractant protein-1 (MCP-1) in metformin-treated diabetics. Normalization of HbA1c to the 84-day average hemoglobin revealed that HE3286 HbA1c decrease correlated with high baseline MCP-1 and MCP-1 decrease in treatment-naïve diabetics. HE3286 decreased insulin resistance, increased the frequency of decreased day 84 HbA1c in metformin-treated subjects, and decreased day 112 HbA1c in treatment-naïve diabetics. HE3286 may be useful to restore metabolic homeostasis in type 2 diabetes.

Abstract A221: Results of preclinical and clinical phase I/II open‐label dose‐ranging trial with HE3235, a synthetic adrenal hormone, in castrate‐resistant prostate cancer

Background: HE3235 (17α‐ethynyl‐5α‐androstane‐3α, 17β‐diol) is an androstenediol analog, which shows activity in preclinical CRPC and breast cancer models. HE3235 decreased AR expression in LNCaP cells in vitro, in the CRPC LuCaP 35V xenograft, and suppressed ER‐a expression in MNU‐induced breast tumors in rats. HE3235 also decreased intra‐tumoral androgen synthesis (both T and DHT) in the LuCaP 35V tumors. In toxicology studies, it decreased steroidogenesis (DHEA and T in male dogs and sex steroids in female rats). HE3235 did not inhibit CYP17 in H295R adrenal tumor cells, but inhibited the conversion of d‐cholesterol to d‐pregnenolone. We are therefore conducting a Phase I/II clinical study in CRPC patients to determine safety, tolerance, pharmacokinetics, maximum tolerated dose and activity of this compound. Methods: Men with CRPC and an ECOG PS of Results: 22 subjects have been treated to date at doses of 10 mg/day (n=7), 20 mg/day (n=9) and 30 mg/day (n=6). Dose escalation continues to determine the MTD. Pharmacokinetics was dose proportional with a drug half‐life of 11–14 hours. HE3235 was well tolerated. Nine of 22 subjects experienced a drop in PSA during treatment with 6 of 22 equal to or greater than 20%. No patient had a 50% decline in PSA. Eight of 17 (47%) subjects who were evaluable for response had stable disease. Median time to progression was 56 days (IQR 55, 224) for 10 mg/day, 112 days (IQR 56, 168) for 20 mg/days, 112 days (IQR 56, >122) for 30 mg/day and 112 days (IQR 56, 168) for all 22 subjects. Conclusion: HE3235 is a novel, small orally delivered compound with preclinical activity for CRPC. It is well tolerated through a dose of 30 mg, and has a T1/2 linear to dose in cohorts tested to date. The trial continues to accrue, and a cohort of patients with chemotherapy‐naive CRPC will be enrolled into the ongoing Phase I/II Study. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A221.