Co-administration Of Substance Research Articles

Pathogenesis-Based Development of Potential Mitigation Strategies for Blinatumomab-Associated Neurologic Events (NEs)

▪Introduction: Blinatumomab (blin), a CD19/CD3 bispecific T-cell engager (BiTE®) antibody construct, has shown clinical efficacy in patients with both B-precursor acute lymphoblastic leukemia (ALL) and B-cell non-Hodgkin lymphoma (NHL). NEs are known blin-associated adverse drug reactions; most NEs occur early during the first treatment cycle and are transient and fully reversible. While NEs are manageable in ALL (favorable risk/benefit profile at a maximum target dose of 28 µg/day), NEs increase in frequency and were dose-limiting in low-grade NHL. The maximum tolerated dose in NHL was 112 µg/day. Here we present translational and single-patient data for potential mitigation strategies for blin-associated NEs.Methods: Pharmacokinetic and pharmacodynamic data from blin clinical studies in NHL and ALL were combined to develop a pathogenetic model for blin-associated NEs. The mitigation potential of substances with antiadhesive properties was studied in vitro in a flow chamber system mimicking blin-induced T-cell redistribution. Three patients with low-grade NHL who had a higher risk of developing NEs due to their low peripheral blood B/T-cell ratios received concomitant pentosan polysulfate (PPS) at infusion start and dose step. ClinicalTrials.gov NCT00274742, NCT00560794, NCT01209286, NCT01471782.Results: T-cell redistribution occurred at infusion start and dose step of blin irrespective of circulating B cells. Concurrently, T cells upregulated the activation marker CD69 and the T-cell adhesion molecule LFA-1 switched from its low to intermediate affinity isoform as shown by binding of soluble ICAM-1. Blood vessel endothelial cells were activated as indicated by release of angiopoietin-2 and clinical signs of peripheral edema. Monocyte and thrombocyte redistribution were also observed. Both B and T cells were detected in cerebrospinal fluid (CSF) of some patients with NEs, and quantifiable blin concentrations were measured in CSF of some patients independent of blood-CSF barrier integrity. A low B/T-cell ratio in peripheral blood (NHL) and/or bone marrow (ALL) has been identified as a potential risk factor for developing NEs. In flow chamber experiments, addition of blin mimicked T-cell redistribution as indicated by reduced T-cell rolling velocity and increased T-cell adhesion to brain microvascular endothelial cells and by upregulation of P-selectin and ICAM-1 adhesion molecules on endothelial cells. Substances potentially interfering with interactions between T cells and endothelial cells (eg, PPS, minocycline) reversed the above-described effects to levels seen without the addition of blin. T-cell kinetics of three patients receiving concomitant PPS at infusion start and dose step showed delayed T-cell redistribution (without circulating B cells) compared with patients without PPS coadministration. These altered T-cell kinetics correlated with less severe NEs; no treatment interruptions or discontinuations were necessary. Finite PPS coadministration had no apparent negative impact on clinical response as two patients achieved an objective response, including one patient who has been in ongoing remission for more than six years.Conclusion: We propose an evidence-based model for the development of blin-associated NEs: 1) First exposure to blin or dose steps increase endothelial adhesiveness of circulating T cells. 2) Adhering T cells activate the endothelium and start extravasating; activated endothelium attracts other circulating leukocytes. 3) At low B/T-cell ratios, extravasated T cells first encountering (rare) B cells in the brain are activated by blin in the perivascular space to locally secret cytokines and chemokines that induce transient neuroinflammation including transmigration of monocytes. 4) Attracted non-T cells and other released factors enhance transient neurotoxicity. Based on this model, T-cell adhesion to blood vessel endothelial cells is the first necessary (but not sufficient) step in the pathogenesis of blin-associated NEs. Coadministration of substances with antiadhesive properties at infusion start and dose steps may offer opportunities to mitigate blin-associated NEs to further improve the safety and efficacy of blin therapy. DisclosuresKlinger:Amgen Research (Munich) GmbH: Employment, Equity Ownership, Patents & Royalties: Blinatumomab. Zugmaier:Amgen: Employment, Patents & Royalties. Naegele:Amgen Research (Munich) GmbH: Employment, Equity Ownership, Patents & Royalties. Goebeler:GEmoAb: Consultancy; Novartis: Consultancy; Roche: Consultancy. Brandl:Amgen: Employment. Kufer:AMGEN Research Munich: Employment, Equity Ownership, Patents & Royalties.

Substance P and glutamate receptor antagonists improve the anti‐arthritic actions of dexamethasone in rats

Current single drug treatments for rheumatoid arthritis have problems of limited efficacy and/or high toxicity. This study investigates the benefits of individual and combined treatments with dexamethasone and substance P and glutamate receptor antagonists in a rat model of arthritis. Arthritis was induced in rats by unilateral intra-articular injection of Freund's complete adjuvant. Separate groups of rats were subjected to the following treatments 15 min before induction of arthritis: (i) control with no drug treatment; (ii) single intra-articular injection of a NK(1) receptor antagonist RP67580; (iii) single intra-articular injection of a NMDA receptor antagonist AP7 plus a non-NMDA receptor antagonist CNQX; (iv) daily oral dexamethasone; and (v) combined treatment with dexamethasone and all of the above receptor antagonists. Knee joint allodynia, swelling, hyperaemia and histological changes were examined over a period of 7 days. Treatment with dexamethasone suppressed joint swelling, hyperaemia and histological changes that include polymorphonuclear cell infiltration, synovial tissue proliferation and cartilage erosion in the arthritic rat knees. Treatment with RP67580 or AP7 plus CNQX did not attenuate hyperaemia or histological changes, but reduced joint allodynia and swelling. Co-administration of dexamethasone with these receptor antagonists produced greater inhibition on joint allodynia and swelling than their individual effects. The data suggest substance P and glutamate contribute to arthritic pain and joint swelling. The efficacy of dexamethasone in reducing arthritic pain and joint swelling can be improved by co-administration of substance P and glutamate receptor antagonists.

Intrathecal substance P augments morphine-induced antinociception: Possible relevance in the production of substance P N-terminal fragments

The present study sought to examine the mechanism of substance P to modulate the antinociceptive action of intrathecal (i.t.) morphine in paw-licking/biting response evoked by subcutaneous injection of capsaicin into the plantar surface of the hindpaw in mice. The i.t. injection of morphine inhibited capsaicin-induced licking/biting response in a dose-dependent manner. Substance P (25 and 50 pmol) injected i.t. alone did not alter capsaicin-induced nociception, whereas substance P at a higher dose of 100 pmol significantly reduced the capsaicin response. Western blots showed the constitutive expression of endopeptidase-24.11 in the dorsal and ventral parts of lumbar spinal cord of mice. The N-terminal fragment of substance P (1–7), which is known as a major product of substance P by endopeptidase-24.11, was more effective than substance P on capsaicin-induced nociception. Combination treatment with substance P (50 pmol) and morphine at a subthreshold dose enhanced the antinociceptive effect of morphine. The enhanced effect of the combination of substance P with morphine was reduced significantly by co-administration of phosphoramidon, an inhibitor of endopeptidase-24.11. Administration of d-isomer of substance P (1–7), [ d-Pro 2, d-Phe 7]substance P (1–7), an inhibitor of [ 3H] substance P (1–7) binding, or antisera against substance P (1–7) reversed the enhanced antinociceptive effect by co-administration of substance P and morphine. Taken together these data suggest that morphine-induced antinociception may be enhanced through substance P (1–7) formed by the enzymatic degradation of i.t. injected substance P in the spinal cord.

Skin toxicity of jet fuels: ultrastructural studies and the effects of substance P

Topical exposure to jet fuel is a significant occupational hazard. Recent studies have focused on dermal absorption of fuel and its components, or alternatively, on the biochemical or immunotoxicological sequelae to exposure. Surprisingly, morphological and ultrastructural analyses have not been systematically conducted. Similarly, few studies have compared responses in skin to that of the primary target organ, the lung. The focus of the present investigation was 2-fold: first, to characterize the ultrastructural changes seen after topical exposure to moderate doses (335 or 67 μl/cm 2) of jet fuels [Jet A, Jet Propellant (JP)-8, JP-8+100] for up to 4 days in pigs, and secondly, to determine if co-administration of substance P (SP) with JP-8 jet fuel in human epidermal keratinocyte cell cultures modulates toxicity as it does to pulmonary toxicity in laboratory animal studies. The primary change seen after exposure to all fuels was low-level inflammation accompanied by formation of lipid droplets in various skin layers, mitochondrial and nucleolar changes, cleft formation in the intercellular lipid lamellar bilayers, as well as disorganization in the stratum granulosum–stratum corneum interface. An increased number of Langerhans cells were also noted in jet fuel-treated skin. These changes suggest that the primary effect of jet fuel exposure is damage to the stratum corneum barrier. SP administration decreased the release of interleukin (IL)-8 normally seen in keratinocytes after JP-8 exposure, a response similar to that reported for SP's effect on JP-8 pulmonary toxicity. These studies provide a base upon which biochemical and immunological data collected in other model systems can be compared.

Spinally-mediated behavioural responses evoked by intrathecal high-dose morphine: possible involvement of substance P in the mouse spinal cord

Intrathecal (i.t.) administration of morphine in the spinal subarachnoid space of mice produced a severe hindlimb scratching followed by biting and licking. The onset of the scratching behaviour was observed 60–70 s after i.t. injection of morphine (60 and 90 nmol), and had a duration of 3–4 min. The morphine-induced behaviour was increased additively by i.t. co-administration of substance P (SP). This characteristic behavioural response was inhibited dose-dependently by i.t. co-administration of the tachykinin NK-1 receptor antagonists, sendide and CP-96,345. Significant antagonistic effects of SP (1–7), a putative antagonist for NK-1 receptors and [ d-Phe 7, d-His 9jSP (6–11), a selective antagonist for SP receptors, were observed against the morphine-induced behaviour. Pretreatment with i.t. SP antiserum and i.t. capsaicin resulted in reduction of the response to morphine. I.t. administration of somatostatin (SOM) antiserum, cysteamine, a relatively selective depletor of SOM and cyclo-SOM, a SOM receptor antagonist, produced no inhibitory effect on the morphine-induced behaviour. These results demonstrate that a spinal system of neurones containing SP may be involved in elicitation of the behavioural episode following i.t. injection of morphine in mice.

Differential antinociceptive effects of sendide, a NK 1-receptor antagonist, and morphine in the capsaicin test

The peptide NK 1-receptor antagonists, sendide and [ d-Trp 7]sendide, have been evaluated for antinociceptive activity in the capsaicin test. Both peptides, injected intrathecally (i.t.) 5 min prior to intraplantar capsaicin, produced a dose-dependent reduction of the capsaicin-induced paw licking response. Naloxone (4.0 mg/kg) pretreatment did not affect sendide- and [ d-Trp 7]sendide-induced antinociception, wherease naloxone at a dose of 0.5 mg/kg antagonized the antinociceptive effect of i.t. administered morphine. Conversely, the antinociceptive action induced by both NK 1-receptor antagonists was reduced significantly by i.t. co-administration of substance P. Morphine-induced antinociception was not antagonized by co-administration of substance P. These results led us to the understanding of differential action mechanism of NK 1-receptor antagonist- and morphine-induced antinociception as assayed by the capsaicin test.

Enhancement of the plasma concentration of albendazole sulphoxide in sheep following coadministration of parenteral netobimin and liver oxidase inhibitors

The effects of methimazole ( mtz), metyrapone ( mtp) and quinine ( qne) on the pharmacokinetics and bioavailability of parenterally administered netobimin ( ntb) and its major metabolites, albendazole sulphoxide ( abzso) and albendazole sulphone ( abzso 2 ), were studied in sheep. ntb trisamine solution was first administered alone at 20 mg kg −1 by subcutaneous injection and then coadministered with either mtz (1·5 mg kg − intramuscularly), mtp (20 mg kg −1 subcutaneously) or qne (30 mg kg −1 intraruminally) in adult sheep. Blood samples were taken serially over a 120 hour period and plasma was analysed for ntb and its metabolites by high performance liquid chromatography. ntb parent drug showed a similar pharmacokinetic behaviour after all parenteral treatments. Both abzso aucs (P<0·01) and C max (P<0·05) were significantly higher in the presence of MTz and MTP than with the treatment with ntb alone. In the presence of each of the oxidation inhibitor compounds, the ratio of auc abzso/abzs0 2 was significantly higher than with the ntb alone treatment. It has been demonstrated that the co-administration of substances which alter liver microsomal oxidation resulted in a modified pharmacokinetic pattern for the metabolites of ntb. Both ntb+mtz and ntb+mtp treatments resulted in an improved pharmacokinetic profile for the anthelmintically active abzso metabolite.

Plasticity of enkephalin, tachykinin and monoamine systems of the basal ganglia following neonatal dopaminergic denervation

The functional role of striatonigral neurokinins were studied by analysing the effects of intranigral injections of substance P and neurokinin A on the extracellular level of dopamine and dihydroxyphenylacetic acid in the striatum, as measured by in vivo microdialysis in rats. Two substance P antagonists, substance Pd-Pro2d-Trp7,9 and substance Pd-Arg1d-Trp7,9 Leu11 were tested and analysed for their ability to block the neurokinin effects.Unilateral injections of substance P (0.00007–7.0 nmol injected in 0.2 μl) as well as neurokinin A (0.009–9.0 nmol) into the substantia nigra, pars reticulata of halothane anaesthetized rats produced long-lasting increases in ipsilateral striatal dopamine and dihydroxyphenylacetic acid levels. The dose-response relationship for substance P on dopamine was biphasic, with maximal effects occurring after the middle dose (0.007–0.07 nmol). The dose-response relationship for neurokinin A was monophasic. Intranigral injections of substance Pd-Pro2d-Trp (0.07–0.7 nmol) or substance Pd-Arg1d-Trp7,9 Leu11 (0.07–0.7 nmol) produced a decrease in striatal dopamine, but an increase in striatal dihydroxyphenylacetic acid. At a low dose (0.07 nmol) substance Pd-Pro2d-Trp7,9 enhanced the dopamine increase produced by intranigral substance P (0.07 nmol) or neurokinin A (0.09), while at a high dose (0.7 nmol) it blocked both substance P and neurokinin A effects. Both doses of substance Pd-Arg1d-Trp7,9 Leu11 (0.07 and 0.7 nmol) blocked the substance P- but not the neurokinin A-induced increase in striatal dopamine. Immunohistochemical analysis revealed that high doses of substance P (7.0 nmol) and neurokinin A (0.9 and 9.0 nmol), as well as substanced-Arg1d-Trp7,9 and substance Pd-Arg1d-Trp7,9 Leu11 (0.07 and 0.7 nmol), induced a restricted loss of tyrosine hydroxylase in dendrites and cells, and neuropeptide K in terminals, at the site of injection. Further analysis shows that co-administration of substance P (0.07 nmol) or neurokinin A (0.09 nmol) did not modify the extent of the depletion of both immunoreactivities induced by substance Pd-Arg1d-Trp7,9 Leu11 (0.7 nmol). The extent of the effect produced by substance Pd-Arg1d-Trp7,9 Leu11 (0.7 nmol) was, however, smaller than the spread of intranigral injection of [125I]Bolton-Hunter-labelled substance Pd-Arg1d-Trp7,9 Leu11, and it is suggested that the “neurotoxic” effects of the substance P antagonists are not primarily involved in their abilities to inhibit striatal dopamine release and block the stimulation of dopamine after intranigral substance P and neurokinin A. We propose that striatonigral substance P and neurokinin A produce a tonic excitatory modulation of nigrostriatal dopamine via neurokinin receptors which can be blocked by substance Pd-Arg1d-Trp7,9. However, substance P and neurokinin A are probably acting via different receptors since substance Pd-Arg1d-Trp7,9 Leu11 blocked substance P but not neurokinin A stimulation of striatal dopamine release.

Role of Substance P Amino Terminal Metabolites in Substance P-Induced Desensitization in Mice

Intrathecal injection of mice with substance P or its C-terminal fragments evokes a well documented behavioral syndrome characterized by caudally-directed biting and scratching. We have previously shown that repeated injections of substance P result in naloxone-sensitive desensitization to this substance P-induced behavior, possibly through interactions of N-terminal fragments of substance P with mu opiate binding sites. The present investigation tests the hypothesis that substance P metabolites play a role in the development of desensitization to substance P by using the biting and scratching behavioral paradigm. While substance P-induced behaviors are produced by as little as 1 pmol of substance P, repeated injections of 7.5 pmol at 60-s intervals was found to be the minimum dose capable of causing desensitization. The C-terminal peptides, substance P3-11 and substance P5-11, elicited substance P-like behaviors, but repeated injection of these compounds did not result in desensitization to this behavior. In contrast to C-terminal fragments, intrathecal injection of N-terminal fragments, (substance P1-4, substance P1-7 and substance P1-9), did not elicit any overt substance P-like behaviors when administered alone, but when co-administered with substance P, decreased the magnitude of substance P-induced behaviors in a dose-related fashion. Various peptidase inhibitors significantly inhibited the catabolism of co-administered substance P. Co-administration of substance P with peptidase inhibitors enhanced and prolonged the substance P-induced behavioral episode, but also prevented the development of substance P-induced desensitization. Together these results support the hypothesis that the accumulation of endogenously generated N-terminal metabolites of substance P mediate desensitization to substance P-induced behaviors in the spinal cord. Substance P metabolism may therefore decrease ongoing substance P activity both by the hydrolysis of the C-terminal portion of substance P as well as by the production of N-terminal metabolites that are capable of inhibiting the effects of substance P.

Effects of intranigral substance p and neurokinin a on striatal dopamine release—i. Interactions with substance p antagonists

The functional role of striatonigral neurokinins were studied by analysing the effects of intranigral injections of substance P and neurokinin A on the extracellular level of dopamine and dihydroxyphenylacetic acid in the striatum, as measured by in vivo microdialysis in rats. Two substance P antagonists, substance P d-Pro 2 d-Trp 7,9 and substance P d-Arg 1 d-Trp 7,9 Leu 11 were tested and analysed for their ability to block the neurokinin effects. Unilateral injections of substance P (0.00007–7.0 nmol injected in 0.2 μl) as well as neurokinin A (0.009–9.0 nmol) into the substantia nigra, pars reticulata of halothane anaesthetized rats produced long-lasting increases in ipsilateral striatal dopamine and dihydroxyphenylacetic acid levels. The dose-response relationship for substance P on dopamine was biphasic, with maximal effects occurring after the middle dose (0.007–0.07 nmol). The dose-response relationship for neurokinin A was monophasic. Intranigral injections of substance P d-Pro 2 d-Trp (0.07–0.7 nmol) or substance P d-Arg 1 d-Trp 7,9 Leu 11 (0.07–0.7 nmol) produced a decrease in striatal dopamine, but an increase in striatal dihydroxyphenylacetic acid. At a low dose (0.07 nmol) substance P d-Pro 2 d-Trp 7,9 enhanced the dopamine increase produced by intranigral substance P (0.07 nmol) or neurokinin A (0.09), while at a high dose (0.7 nmol) it blocked both substance P and neurokinin A effects. Both doses of substance P d-Arg 1 d-Trp 7,9 Leu 11 (0.07 and 0.7 nmol) blocked the substance P- but not the neurokinin A-induced increase in striatal dopamine. Immunohistochemical analysis revealed that high doses of substance P (7.0 nmol) and neurokinin A (0.9 and 9.0 nmol), as well as substance d-Arg 1 d-Trp 7,9 and substance P d-Arg 1 d-Trp 7,9 Leu 11 (0.07 and 0.7 nmol), induced a restricted loss of tyrosine hydroxylase in dendrites and cells, and neuropeptide K in terminals, at the site of injection. Further analysis shows that co-administration of substance P (0.07 nmol) or neurokinin A (0.09 nmol) did not modify the extent of the depletion of both immunoreactivities induced by substance P d-Arg 1 d-Trp 7,9 Leu 11 (0.7 nmol). The extent of the effect produced by substance P d-Arg 1 d-Trp 7,9 Leu 11 (0.7 nmol) was, however, smaller than the spread of intranigral injection of [ 125I]Bolton-Hunter-labelled substance P d-Arg 1 d-Trp 7,9 Leu 11, and it is suggested that the “neurotoxic” effects of the substance P antagonists are not primarily involved in their abilities to inhibit striatal dopamine release and block the stimulation of dopamine after intranigral substance P and neurokinin A. We propose that striatonigral substance P and neurokinin A produce a tonic excitatory modulation of nigrostriatal dopamine via neurokinin receptors which can be blocked by substance P d-Arg 1 d-Trp 7,9. However, substance P and neurokinin A are probably acting via different receptors since substance P d-Arg 1 d-Trp 7,9 Leu 11 blocked substance P but not neurokinin A stimulation of striatal dopamine release.