Platelet PECAM-1 Inhibits Thrombus Formation In Vivo

Platelet endothelial cell adhesion molecule-1 (PECAM-1) is a cell surface glycoprotein receptor expressed on a range of blood cells including platelets, and is also on vascular endothelial cells. PECAM-1 possesses adhesive and signalling properties, the latter being mediated by an Immunoreceptor Tyrosine-based Inhibitory Motif present on the cytoplasmic tail of the protein. Recent studies in vitro have demonstrated that PECAM-1 signalling inhibits the aggregation of platelets. In the present study we have utilised PECAM-1 deficient mice and radiation chimeras to investigate the function of this receptor in the regulation of thrombus formation. Using intravital microscopy and laser induced injury to cremaster muscle arterioles, we show that thrombi formed in PECAM-1 deficient mice were larger, formed more rapidly than in control mice and were more stable. Larger thrombi were also formed in control mice transplanted with PECAM-1 deficient bone marrow, in comparison to control-transplanted mice. A ferric chloride model of thrombosis was used to investigate thrombus formation in carotid arteries. In PECAM-1 deficient mice the time to 75% vessel occlusion was significantly shorter than in control mice. These data provide evidence for the involvement of platelet PECAM-1 in the negative regulation of thrombus formation

Patient-reported health-related quality of life, work productivity, and activity impairment during treatment with ALO-02 (extended-release oxycodone and sequestered naltrexone) for moderate-to-severe chronic low back pain

Abstract Background The efficacy of ALO-02, an abuse-deterrent formulation containing extended-release oxycodone and sequestered naltrexone, in the treatment of chronic low back pain (CLBP) was studied in a 12-week randomized controlled trial. Primary efficacy endpoint results have been published previously (Rauck et al., 2015). The current paper focuses on patient-reported outcomes for health-related quality of life (HRQL), work productivity, and activity impairment that were assessed during this study. Methods This was a double-blind, placebo-controlled, randomized withdrawal study in patients with moderate-to-severe CLBP. After a screening period (≤2 weeks), patients entered an open-label titration period (4–6 weeks). Treatment responders were then randomized to a double-blind placebo-controlled treatment period (12 weeks). HRQL was assessed using changes in the Short Form-36 v2 Health Survey (SF-36v2) and the EuroQol-5 Dimensions Health Questionnaire 3-Level version (EQ-5D-3L). Work productivity and regular activities were evaluated using the Work Productivity and Activity Impairment Questionnaire: Specific Health Problem (WPAI:SHP). Results A total of 410 patients received ALO-02 during the open-label titration period, of which 280 (intent-to-treat (ITT) population) were treated during the double-blind placebo-controlled treatment period (placebo, n = 134; ALO-02, n = 146). Significant improvement was observed for all SF-36v2 subscales and component scores (p < 0.005) and the EQ-5D-3L summary index and visual analog scale (p < 0.0001) during the titration period. Improvement was also significant (p < 0.0001) for all WPAI:SHP outcomes except ‘work time missed due to CLBP’ for the titration period. Significant differences favoring ALO-02 compared with placebo were only observed for the SF-36v2 Bodily Pain subscale (p ≤ 0.0232; ITT population) during the double-blind treatment period and the overall study period (screening to the end of the double-blind treatment period). The percentage change in activity impairment due to low back pain subscale of the WPAI:SHP significantly favored ALO-02 compared with placebo for the ITT population when considering the overall study period (p = 0.0040). Conclusions HRQL, work productivity, and activity impairment may be improved with ALO-02 treatment. Trial registration ClinicalTrials.gov NCT01571362 , registered April 3, 2012

Peripheral Nerve Safety of Nerve Growth Factor Inhibition by Tanezumab: Pooled Analyses of Phase III Clinical Studies in Over 5000 Patients with Osteoarthritis

BACKGROUND: Tanezumab, a humanized anti-nerve growth factor antibody, was developed for the treatment of pain associated with osteoarthritis. Due to its mechanism of action, peripheral nerve safety was assessed in all clinical studies. OBJECTIVES: To summarize the neurological safety of intravenous (IV) and subcutaneous (SC) tanezumab versus placebo in patients with osteoarthritis. METHODS: Data were pooled from 3389 patients across seven studies that investigated IV administration, and from 1840 patients across three studies that investigated SC administration. The treatment period of each study ranged from 16 to 24 weeks, and follow-up periods ranged from 8 to 24 weeks. Neurological safety evaluations focused on adverse events (AEs) of abnormal peripheral sensation (APS), neurologic examinations, and consultations. RESULTS: Across datasets, the incidence of AEs of APS was higher in tanezumab groups versus placebo. Paresthesia and hypoesthesia were the most frequently reported AEs in tanezumab-treated patients, compared with placebo. In both datasets, most AEs were of mild severity, resolved, and rarely resulted in discontinuation. In all treatment groups in both IV and SC studies, over 90% of patients had no new or worsened neurological examination abnormalities at the last study visit. Across datasets, mononeuropathy was diagnosed more frequently in tanezumab groups compared with placebo. Polyneuropathy was diagnosed in ≤ 0.9% of patients in tanezumab and placebo groups. CONCLUSIONS: Tanezumab IV or SC had an increased incidence of AEs of APS, such as paresthesia and hypoesthesia, and diagnoses of mononeuropathy compared with placebo. However, tanezumab was not associated with generalized peripheral neuropathy. GOV IDENTIFIERS: NCT00733902, NCT00744471, NCT00830063, NCT00863304, NCT00863772, NCT01089725, NCT00985621, NCT02697773, and NCT02709486

Effect of Tanezumab on Joint Pain, Physical Function, and Patient Global Assessment of Osteoarthritis Among Patients With Osteoarthritis of the Hip or Knee: A Randomized Clinical Trial.

Importance: Patients with osteoarthritis (OA) may remain symptomatic with traditional OA treatments. Objective: To assess 2 subcutaneous tanezumab dosing regimens for OA. Design, Setting, and Participants: A randomized, double-blind, multicenter trial from January 2016 to May 14, 2018 (last patient visit). Patients enrolled were 18 years or older with hip or knee OA, inadequate response to OA analgesics, and no radiographic evidence of prespecified joint safety conditions. Interventions: Patients received by subcutaneous administration either tanezumab, 2.5 mg, at day 1 and week 8 (n = 231); tanezumab, 2.5 mg at day 1 and 5 mg at week 8 (ie, tanezumab, 2.5/5 mg; n = 233); or placebo at day 1 and week 8 (n = 232). Main Outcomes and Measures: Co-primary end points were change from baseline to week 16 in Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) Pain (0-10, no to extreme pain), WOMAC Physical Function (0-10, no to extreme difficulty), and patient global assessment of osteoarthritis (PGA-OA) (1-5, very good to very poor) scores. Results: Among 698 patients randomized, 696 received 1 or more treatment doses (mean [SD] age, 60.8 [9.6] years; 65.1% women), and 582 (83.6%) completed the trial. From baseline to 16 weeks, mean WOMAC Pain scores decreased from 7.1 to 3.6 in the tanezumab, 2.5 mg, group; 7.3 to 3.6 in the tanezumab, 2.5/5 mg, group; and 7.3 to 4.4 in the placebo group (least squares mean differences [95% CI] vs placebo were -0.60 [-1.07 to -0.13; P = .01] for tanezumab, 2.5 mg, and -0.73 [-1.20 to -0.26; P = .002] for tanezumab, 2.5/5 mg). Mean WOMAC Physical Function scores decreased from 7.2 to 3.7 in the 2.5-mg group, 7.4 to 3.6 in the 2.5/5-mg group, and 7.4 to 4.5 with placebo (differences vs placebo, -0.66 [-1.14 to -0.19; P = .007] for tanezumab, 2.5 mg, and -0.89 [-1.37 to -0.42; P \u3c .001] for tanezumab, 2.5/5 mg). Mean PGA-OA scores decreased from 3.4 to 2.4 in the 2.5-mg group, 3.5 to 2.4 in the 2.5/5-mg group, and 3.5 to 2.7 with placebo (differences vs placebo, -0.22 [-0.39 to -0.05; P = .01] for tanezumab, 2.5 mg, and -0.25 [-0.41 to -0.08; P = .004] for tanezumab, 2.5/5 mg). Rapidly progressive OA occurred only in tanezumab-treated patients (2.5 mg: n = 5, 2.2%; 2.5/5 mg: n = 1, 0.4%). The incidence of total joint replacements was 8 (3.5%), 16 (6.9%), and 4 (1.7%) in the tanezumab, 2.5 mg; tanezumab, 2.5/5 mg; and placebo groups, respectively. Conclusions and Relevance: Among patients with moderate to severe OA of the knee or hip and inadequate response to standard analgesics, tanezumab, compared with placebo, resulted in statistically significant improvements in scores assessing pain and physical function, and in PGA-OA, although the improvements were modest and tanezumab-treated patients had more joint safety events and total joint replacements. Further research is needed to determine the clinical importance of these efficacy and adverse event findings. Trial Registration: ClinicalTrials.gov Identifier: NCT02697773

Platelet PECAM-1 Inhibits Thrombus Formation In Vivo

Platelet endothelial cell adhesion molecule-1 (PECAM-1) is a cell surface glycoprotein receptor expressed on a range of blood cells including platelets, and is also on vascular endothelial cells. PECAM-1 possesses adhesive and signalling properties, the latter being mediated by an Immunoreceptor Tyrosine-based Inhibitory Motif present on the cytoplasmic tail of the protein. Recent studies in vitro have demonstrated that PECAM-1 signalling inhibits the aggregation of platelets. In the present study we have utilised PECAM-1 deficient mice and radiation chimeras to investigate the function of this receptor in the regulation of thrombus formation. Using intravital microscopy and laser induced injury to cremaster muscle arterioles, we show that thrombi formed in PECAM-1 deficient mice were larger, formed more rapidly than in control mice and were more stable. Larger thrombi were also formed in control mice transplanted with PECAM-1 deficient bone marrow, in comparison to control-transplanted mice. A ferric chloride model of thrombosis was used to investigate thrombus formation in carotid arteries. In PECAM-1 deficient mice the time to 75% vessel occlusion was significantly shorter than in control mice. These data provide evidence for the involvement of platelet PECAM-1 in the negative regulation of thrombus formation

Platelet PECAM-1 Inhibits Thrombus Formation In Vivo

Platelet endothelial cell adhesion molecule- 1 (PECAM-1) is a cell surface glycoprotein receptor expressed on a range of blood cells, including platelets, and on vascular endothelial cells. PECAM-1 possesses adhesive and signaling properties, the latter being mediated by immunoreceptor tyrosine-based inhibitory motifs present on the cytoplasmic tail of the protein. Recent studies in vitro have demonstrated that PECAM-1 signaling inhibits the aggregation of platelets. In the present study we have used PECAM-1– deficient mice and radiation chimeras to investigate the function of this receptor in the regulation of thrombus formation. Using intravital microscopy and laser induced injury to cremaster muscle arterioles, we show that thrombi formed in PECAM-1–deficient mice were larger, formed more rapidly than in control mice, and were more stable. Larger thrombi were also formed in control mice that received transplants of PECAM-1–deficient bone marrow, in comparison to mice that received control transplants. A ferric chloride model of thrombosis was used to investigate thrombus formation in carotid arteries. In PECAM-1–deficient mice the time to 75% vessel occlusion was significantly shorter than in control mice. These data provide evidence for the involvement of platelet PECAM-1 in the negative regulation of thrombus formation. (Blood. 2006;107:535-541