Pregnancy Outcomes in the Tofacitinib Safety Databases for Rheumatoid Arthritis and Psoriasis.

INTRODUCTION: Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA), and is being investigated for the treatment of psoriasis. Both conditions can present in women of child-bearing potential, but pregnancy was an exclusion and discontinuation criterion in tofacitinib randomized controlled trials (RCTs) because of the unknown effects of tofacitinib on mother and child. Tofacitinib is a small molecule that has the potential to cross the placenta. OBJECTIVE: The objective was to report outcomes of pregnancy cases identified through April 2014 from tofacitinib RA/psoriasis RCTs, RA post-approval non-interventional studies, and spontaneous adverse-event reporting. METHODS: Pregnancy outcomes were categorized as follows: healthy newborn, medical termination, fetal death, congenital malformation, spontaneous abortion, or pending/lost to follow-up. RESULTS: Out of 9815 patients, 1821 female patients of child-bearing age were enrolled in the RA/psoriasis RCTs; 47 women became pregnant, including 33 who received tofacitinib monotherapy, 13 who received combination therapy with methotrexate (RA patients only), and one patient whose therapy was still blinded. No fetal deaths were reported. One congenital pulmonary valve stenosis (monotherapy, n = 1), seven spontaneous abortions (monotherapy, n = 4; combination therapy, n = 3), and eight medical terminations (monotherapy, n = 4; combination therapy, n = 3; blinded therapy, n = 1) were identified. Remaining cases reported healthy newborns (n = 25) or were pending/lost to follow-up (n = 6). Forty-four cases of paternal exposure to tofacitinib were reported (monotherapy, n = 43; combination therapy, n = 1), including five spontaneous abortions (monotherapy, n = 4; combination therapy, n = 1), 23 healthy newborns, and 16 pending/lost to follow-up. CONCLUSIONS: The pregnancy outcomes reported in this small number of RA/psoriasis patients appear similar to those observed in the general population and in patients treated with biologic therapies for inflammatory diseases. However, definitive conclusions cannot be drawn, and pregnancy outcomes in patients receiving tofacitinib will continue to be monitored.

Passive limb movement augments ventilatory response to CO2 via sciatic inputs in anesthetized rats.

Passive limb movement (PLM) in humans induces a phasic hyperpnea, but the underlying physiological mechanisms remain unclear. We asked whether PLM in anesthetized rats would produce a similar phasic hyperpnea associated with an augmented ventilatory (V(E)) response to CO(2) that is dependent on sciatic afferents. The animals underwent 5 min threshold PLM, 3 min hypercapnia (5% CO(2)), and their combination (CO(2) exposure at the end of 2nd min of 5-min PLM) before and after bilateral transection of the sciatic nerves. We found that a threshold PLM evoked a phasic hyperpnea, similar to that denoted in humans, and an augmented V(E) response to CO(2). Both responses were greatly diminished by sciatic nerve transection. Moreover, similar responses were also evoked by electrically stimulating the central end of the transected sciatic nerve. Our findings suggest an ability of the sciatic afferents to augment the V(E) response to CO(2) that likely contributes to the PLM-induced hyperpnea.

Neurotoxic effects of zoniporide: a selective inhibitor of the NA+/H+ exchanger isoform 1.

Zoniporide, an inhibitor of the Na+-H+ exchanger-1, was administered by continuous intravenous infusion to rats and dogs for up to 1 month. In 1-month studies, histological and functional changes were observed in select portions of the peripheral nervous system; however, these findings were not detected in 2-week studies at similar or higher doses. In the 1-month rat study, there was dose-dependent, minimal, focal, or multifocal nerve fiber (axonal) degeneration in the spinal cord and/or sciatic nerve. In a follow-up rat study, findings included slowing of caudal nerve conduction velocity and axonal degeneration in the spinal cord (dorsal funiculus), dorsal roots, dorsal root ganglia (DRG), radial, sciatic, and tibial nerves. In the 1-month dog study, there was impairment of the patellar reflex and associated postural reaction changes, minimal to marked proximal nerve fiber degeneration in the DRG, and minimal nerve fiber degeneration in the dorsal roots and funiculi of the spinal cord. Minimal nerve fiber degeneration of equivocal significance was noted in various peripheral nerves. Taken together, these findings were consistent with a specific effect on peripheral sensory nerve fibers. These studies demonstrated that zoniporide produces clinical, electrophysiologic, and microscopic evidence of peripheral sensory axonopathy and establishes the importance of careful preclinical evaluation of neurological function.

Hyperventilation evoked by activation of the vicinity of the caudal inferior olivary nucleus depends on the fastigial nucleus in anesthetized rats.

Several studies have demonstrated that cerebellar deep nuclei, particularly the rostral fastigial nucleus (FNr), are involved in respiratory modulation. These nuclei receive inputs from the contralateral caudal inferior olivary nuclei of the medulla. The objectives of this study were to determine whether electrical and chemical activation of the vicinity of the caudal inferior olivary nuclei (vIOc) affected respiration and, if true, whether the FNr was involved in the vIOc stimulation-evoked ventilatory responses. Experiments were conducted in 30 anesthetized and spontaneously breathing rats. Our results showed that 1) electrical (25 or 100 microA at 10 or 20 Hz for 10 s) and chemical (1 or 100 mM, 25-50 nl N-methyl-D-aspartate) stimulation of the vIOc augmented ventilation predominantly via increasing tidal volume; 2) the responses to the electrical stimulation were almost eliminated by lesion of the contralateral FNr via microinjection of ibotenic acid; and 3) the respiratory responses to electrical stimulation in the vicinity of the rostral IO were 65-70% smaller compared with that evoked by vIOc stimulation. These findings strongly suggest that vIOc neurons play a significant role in modulation of respiratory activity, largely depending on their projections to the FNr.

Purkinje cell degeneration elevates eupneic and hypercapnic ventilation in rats.

Previous studies have demonstrated that among cerebellar nuclei, the fastigial nucleus (FN) plays a major role in facilitation of respiration, especially during hypercapnia. Since the FN primarily receives inhibitory afferents from Purkinje cells (PCs), we hypothesized that degeneration of PCs would increase both eupneic and hypercapnic ventilation. Experiments were carried out on 20 animals (n=10 for both normal and PC-degenerated) that were divided into three groups based on the different preparations used, i.e., four pairs for the awake, three pairs for the anesthetized, and three other pairs initially for the awake and subsequently for the anesthetized. The awake normal and PCD rats were separately placed in an unrestrained whole-body plethysmograph and ventilatory parameters measured before (room air) and during hypercapnia (5% CO2 + 21% O2 + 74% N2) for 30 min. The anesthetized animals were exposed to the same level of hypercapnia applied for approximately 5 min. The results showed that both eupneic breathing and hypercapnia-induced ventilatory augmentation were significantly greater in the awake PCD rat than those observed in the normal one, primarily due to a remarkable elevation in VT with little changes in f. The same results were also observed in anesthetized preparations. A Fos protein Immunocytochemical approach was employed to determine the effect of degeneration on PCs and FN neuronal activity. Fos expression of PCs was very intensive in normal rats, but absent or diminished in PCD rats. In sharp contrast, FN Fos expression was obscure in normal rats, but very apparent in PCD rats. These data suggest that PCs play an inhibitory role in modulation of eupneic and hypercapnic ventilation via inhibiting FN neuronal activity.

Medial vestibular nucleus mediates the cardiorespiratory responses to fastigial nuclear activation and hypercapnia.

Electrical stimulation of the cerebellar fastigial nucleus (FN) evokes hyperventilation and hypertension responses that are similar to those induced by stimulation of the medial region of the vestibular nucleus (VNM). Because there are mutual projections between these two nuclei morphologically, we hypothesized that the FN-mediated cardiorespiratory responses were related to the integrity of the VNM. Experiments were conducted on 21 anesthetized, tracheotomized, and spontaneously breathing rats. Electrical stimulation (approximately 10 s) of the FN was used to evoke cardiorespiratory responses, and the same stimulus was repeated 30-45 min after bilateral lesions of the VNM by local microinjection of ibotenic acid (100 mM, 100 nl). We found that FN stimulation-induced hyperventilation and hypertension were attenuated significantly by the lesions. The role of the VNM in the ventilatory responses to chemical challenges was subsequently defined. The animals were exposed to hypercapnia (10% CO2) and hypoxia (10% O2) for 1-2 min randomly before and after VNM lesions. The results showed that VNM lesions significantly attenuated the cardiorespiratory responses to hypercapnia but not to hypoxia, with little effect on baseline respiratory variables. These findings suggest that the VNM is required for full expression of the cardiorespiratory responses to electrical stimulation of the FN as well as to hypercapnia. However, neurons within the VNM do not appear to be critical for maintaining eupneic breathing and the cardiorespiratory responses to hypoxia.

Zoniporide: a potent and selective inhibitor of the human sodium-hydrogen exchanger isoform 1 (NHE-1).

The sodium-hydrogen exchanger isoform-1 (NHE-1) plays an important role in the myocardial response to ischemia-reperfusion; inhibition of this exchanger protects against ischemic injury, including reduction in infarct size. Herein we describe a novel, potent, and highly selective NHE-1 inhibitor, zoniporide (CP-597,396; [1-(quinolin-5-yl)-5-cyclopropyl-1H-pyrazole-4-carbonyl] guanidine). Zoniporide inhibits human NHE-1 with an IC(50) of 14 nM, has >150-fold selectivity vs. other NHE isoforms, and potently inhibits ex vivo NHE-1-dependent swelling of human platelets. This compound is well tolerated in preclinical animal models, exhibits moderate plasma protein binding, has a t(1/2) of 1.5 h in monkeys, and has one major active metabolite. In both in vitro and in vivo rabbit models of myocardial ischemia-reperfusion injury, zoniporide markedly reduced infarct size without adversely affecting hemodynamics or cardiac function. In the isolated heart (Langendorff), zoniporide elicited a concentration-dependent reduction in infarct size (EC(50) = 0.25 nM). At 50 nM it reduced infarct size by 83%. This compound was 2.5-20-fold more potent than either eniporide or cariporide (EC(50)s of 0.69 and 5.11 nM, respectively), and reduced infarct size to a greater extent than eniporide. In open chest, anesthetized rabbits, zoniporide also elicited a dose-dependent reduction in infarct size (ED(50) = 0.45 mg/kg/h) and inhibited NHE-1-mediated platelet swelling (93% inhibition at 4 mg/kg/h). Furthermore, zoniporide attenuated postischemic cardiac contractile dysfunction in conscious primates, and reduced both the incidence and duration of ischemia-reperfusion-induced ventricular fibrillation in rats. Zoniporide represents a novel class of potent and selective human NHE-1 inhibitors with potential utility for providing cardioprotection in a clinical setting.

Activation of different vestibular subnuclei evokes differential respiratory and pressor responses in the rat.

Activation of the vestibular system can either increase or decrease ventilation. The objectives of the present study were to clarify whether these different responses are the result of activating different vestibular subnuclei, by addressing three questions. Do neurones within the medial, lateral and spinal vestibular nuclei (VN(M), VN(L) and VN(S), respectively) function differently in respiratory modulation? Is the ventral medullary nucleus gigantocellularis (NGC) required to fully express the VN-mediated respiratory responses? Is glutamate, by acting on N-methyl-D-aspartic acid (NMDA) receptors in the vestibular subnuclei, capable of modulating respiration? In anaesthetized, tracheotomized and spontaneously breathing rats, electrical stimuli (< 10 s) applied in the VN(L) and VN(S) significantly elevated ventilation by 35 % and 30 % (P < 0.05), respectively. However, VN(M) stimulation produced statistically significant (P < 0.05) changes that differed depending upon the stimulation site: either ventilatory inhibition (by 40 % in 57 % of the trials) or excitation (by 55 % in 43 % of trials), and which were often accompanied by a pressor response. These electrical-stimulation-evoked cardiorespiratory responses were almost eliminated following microinjection of ibotenic acid into the stimulation sites (P < 0.05) or bilaterally into the NGC (P < 0.05). As compared to vehicle, microinjection of NMDA into the unilateral VN(M), VN(L) and VN(S) significantly increased ventilation to 74 %, 58 % and 60 % (P < 0.05), respectively, with no effect on arterial blood pressure. These data suggest that neurones within the vestibular subnuclei play different roles in cardiorespiratory modulation, and that the integrity of the NGC is essential for the full expression of these VN-mediated responses. The evoked respiratory excitatory responses are probably mediated by glutamate acting on NMDA receptors, whereas the neurotransmitters involved in VN(M)-mediated respiratory inhibition and hypertension remain unknown.

Role of the cerebellar deep nuclei in respiratory modulation.

The cerebellum contains three deep nuclei, i.e., the fastigial, interposed and lateral nucleus. Recent studies demonstrate that these nuclei play different roles in respiratory modulation. Activation of fastigial nuclear neurons predominantly increases ventilation via elevation of respiratory frequency and/or tidal volume. Ablation of the fastigial nucleus did not significantly alter eupneic breathing, but did markedly attenuate the respiratory response to medium and severe hypercapnia as well as hypoxia. The fastigial nucleus contains respiratory-modulated neurons and about 25% of these neurons do not show their respiratory-related phasic activity until exposed to hypercapnia. The fastigial nucleus also contains CO2/H+ chemosensitive sites that contributed to the respiratory response to hypercapnia. Therefore, it is concluded that fastigial nuclear facilitatory influence on chemoreflexes emerges during hypercapnia via recruiting intrinsic chemoreception and respiratory-modulated neurons. Full expression of the fastigial nucleus-mediated respiratory responses depends on the integrity of the medullary gigantocellular nucleus at least partially via monosynaptic projections. Additionally, the fastigial nucleus receives inhibitory inputs primarily from Purkinje cells located in the medial vermis and recent observations indicate that simulation of these Purkinje cells inhibits respiration. As compared to chemoreflexes, fastigial nuclear role in the respiratory mechanoreflexes is not significant. The studies related to the role of the interposed and lateral nucleus in eupneic breathing are limited and the results appear controversial. However, there is evidence to show that the interposed nucleus contains respiratory-modulated neurons and is involved in coughing motor control.