Safety, Pharmacokinetics, and Pharmacodynamics Study in Healthy Subjects of Oral NEO6860, a Modality Selective Transient Receptor Potential Vanilloid Subtype 1 Antagonist.

Most previous transient receptor potential vanilloid subtype 1 (TRPV1) antagonist programs have been put on hold, mainly because of on-target adverse events: hyperthermia and impaired noxious heat sensation. NEO6860 is a TRPV1 antagonist, blocking capsaicin activation of the target, with little or no effect against pH or heat activation. The hypothesis is that this pharmacological profile will translate into analgesia without undesired effects on the body temperature or heat-pain threshold. This phase I, double blind, placebo controlled, ascending dose study, included 64 subjects. Pharmacodynamics (intradermal capsaicin test) was explored. The study was comprised of 6 dose levels (50, 100, 200, 400, 800, and 1,200 mg) and 2 doses of 500 mg, 12 hours apart. NEO6860 was rapidly absorbed and systemic exposure increases were less than dose proportional. Median time of maximum observed plasma concentration values ranged from 2 to 3 hours. The mean apparent plasma terminal elimination half-life was between 4 and 8 hours. No significant food-effect or gender-effect was observed. The most frequently reported events were feeling hot, headache, paresthesia, nausea, and dizziness. Single oral doses of up to 800 mg and two 500-mg doses administered 12 hours apart of NEO6860 were well tolerated in this study. Unlike other TRPV1 antagonists, no clinically significant increase in temperature or heat pain threshold/tolerance was noted despite thorough and specific monitoring of these parameters. At all doses, most subjects reported a sensation of "feeling hot," with a rapid onset and transient. NEO6860 showed an improvement in the pharmacodynamics parameters (evoked pain and secondary hyperalgesia) at 3 and 8 hours post NEO6860 dosing. PERSPECTIVE: This first in human study on NEO6860, showed that an antagonist of TRPV1, blocking only the activation by capsaicin has been identified. This finding paves the way for the development of a new powerful analgesic for many pain conditions, without the fear of the side effects observed with previous TRPV1 antagonists.

Demographic and clinical features of inclusion body myositis in North America.

INTRODUCTION: Few studies of the demographics, natural history, and clinical management of inclusion body myositis (IBM) have been performed in a large patient population. To more accurately define these characteristics, we developed and distributed a questionnaire to patients with IBM. METHODS: A cross-sectional, self-reporting survey was conducted. RESULTS: The mean age of the 916 participants was 70.4 years, the male-to-female ratio was 2:1, and the majority reported difficulty with ambulation and activities of daily living. The earliest symptoms included impaired use and weakness of arms and legs. The mean time from first symptoms to diagnosis was 4.7 years. Half reported that IBM was their initial diagnosis. A composite functional index negatively associated with age and disease duration, and positively associated with participation in exercise. CONCLUSIONS: These data are valuable for informing patients how IBM manifestations are expected to impair daily living and indicate that self-reporting could be used to establish outcome measures in clinical trials.

Reproducibility of the semiflexed (metatarsophalangeal) radiographic knee position and automated measurements of medial tibiofemoral joint space width in a multicenter clinical trial of knee osteoarthritis.

OBJECTIVE: To determine the baseline and longitudinal consistency in reproducibility of the semiflexed metatarsophalangeal (MTP) position in repeat examinations of patients with knee osteoarthritis (OA) recruited for a multicenter clinical trial that terminated within one year (mean duration 0.81 yr), based on precise measurements both of minimum medial tibiofemoral compartment joint space width (JSW) and of tibial inter-rim distance. METHODS: Two technologists from 8 and one technologist from 14 clinical radiology units had received previous training in performing nonfluoroscopic semiflexed MTP knee examinations and in quality control criteria for film acceptance. Patients (N = 402; F = 269) were recruited from 58 rheumatology sites and referred to 22 centers, or "x-ray hubs," across North America. At baseline and at study exit, both knees were x-rayed twice on the same day. All films had quality control, and accepted films were digitized at the Central Radiographic Facility and transmitted to the Central Analysis Facility for computerized measurement of minimum medial compartment JSW and tibial inter-rim distance. JSW loss was calculated in the placebo group for the study period. RESULTS: The median SD of the difference in JSW between same-day test/retest film pairs was 0.9 mm for 767 baseline film pairs (knees with JSW > 0 mm), and 0.08 mm for 631 exit film pairs. JSW reproducibility was unaffected by subject's sex, age, and degree of JSW loss. Among all x-ray hubs, JSW reproducibility was excellent in 14 (SD < 0.1 mm), good in 6 (0.1 < SD < 0.2 mm), and moderate in 2 hubs (0.2 < SD < 0.3 mm). No statistical difference was found in technologists' ability either in positioning OA knees or in their test/retest reproducibility in repositioning joints at baseline and at study exit. JSW did not alter significantly during the study period. CONCLUSION: The protocol for the semiflexed MTP knee position provides a highly reproducible method for anatomically repositioning the knee and for measuring JSW, necessary for OA clinical trials. It is a simple method that can be employed readily at clinical radiology units, as shown by the similarity in JSW precision between x-ray hubs. The results from this large dataset show that throughout the study precise measurements of JSW were obtained from same-day repeat radiographs, findings that together with previous single-center studies confirm the reliability of this method for clinical trial use.

Molecular changes in human osteoarthritic cartilage after 3 weeks of oral administration of BAY 12-9566, a matrix metalloproteinase inhibitor.

OBJECTIVE: To determine the effect of BAY 12-9566, a matrix metalloproteinase inhibitor, on articular cartilage metabolism in patients with osteoarthritis (OA). METHODS: Thirty-five patients with OA were randomized to receive oral daily dosing of BAY 12-9566 (25, 100, or 400 mg) or placebo for 3 weeks prior to knee surgery. Cartilage samples were obtained at surgery and examined for markers of proteoglycan aggrecan turnover (846 epitope, a putative synthesis marker, and keratan sulfate epitope content) and type II collagen synthesis (C-propeptide content), cleavage by collagenase (COL 2-3/4C short), denaturation, and content (COL2-3/4m epitope). BAY 12-9566 concentrations were measured by HPLC in serum, synovial fluid, and cartilage. RESULTS: Comparisons between study drug and placebo treatments revealed that at the 100 mg dose there was a significant increase in the 846 epitope (p = 0.012). Total type II collagen content was also higher at this dosage (p = 0.012). Alterations in collagen degradation and synthesis were not detected. CONCLUSION: BAY 12-9566 at daily doses of 100 mg significantly altered proteoglycan turnover, resulting in a cartilage composition reflected by the content of the 846 epitope that is more characteristic of a young growing individual. The increase in this epitope may signify increased matrix synthesis. The increase in type II collagen content was unexpected, since there was no other evidence for altered collagen turnover. However, increased matrix assembly would also be indicated by this increased content.