OP0056 PERSISTENCE OF BIOLOGIC TREATMENT IN PSORIATIC ARTHRITIS: A POPULATION-BASED STUDY IN SWEDEN

Background:

Psoriatic arthritis (PsA) is a chronic, heterogeneous, immune-mediated seronegative arthritis characterized by joint inflammation in people with skin psoriasis (PsO). In recent years several effective biologic treatments such as tumour necrosis factor inhibitors (TNFi), interleukin (IL) 12 and 23 inhibitors (IL-12/23i), and IL 17 inhibitors (IL-17i) have been introduced for PsA. Discontinuation (non-persistence) of therapy is usually a consequence of lack of effect and intolerability.

Objectives:

Compare time to discontinuation of TNFi (adalimumab, ADA), IL-17i (secukinumab, SEC), and IL-12/23i (ustekinumab, UST) treatment exposures and the association with previous biologic treatment experience.

Methods:

Population-based national health data from the Swedish Patient Registry, Prescribed Drug Registry and Cause of Death Registry were linked at the patient level and used to identify treatment exposures in PsA patients initiating ADA, SEC, or UST between January 2008 and September 2018. Discontinuation was defined as a treatment switch to any other PsA-indicated biologic, or failure to re-dispense treatment within a grace period following end of drug supplied. The grace period, defined as the number of days between end of drug supply and re-dispensation during which a patient is considered to be on active treatment, was set dynamically to the number of days of drug supplied in the primary analysis. As a sensitivity analysis, a fixed 90-day grace period was used. Supply was calculated as total milligrams dispensed divided by maintenance dose posology, where the following assumptions were made due to the limitations of the administrative data used: UST patients’ weight corresponded to the amount of drug dispensed (both 45mg and 90mg dispensations last 84 days), SEC patients with prior TNFi experience consumed 300mg/28 days and all others consumed 150mg/28 days, and ADA patients consumed 40mg/14 days. Adjusted hazard ratios (HR) for time to discontinuation were calculated using a Cox proportional hazards model. Covariates for age, marital status, and previous biologic treatment experience were assessed at the initiation of treatment exposure, while comorbidity including skin PsO was assessed during the two years prior. Exposures without discontinuation events were censored at death or end of follow-up. The study was approved by the Stockholm Regional Ethical Review Board.

Results:

3,620 discontinuation events were observed in the main analysis across 4,649 treatment exposures (ADA: 3,255; SEC: 887; UST: 507) (Figure 1, unadjusted). 3,162 events were observed in the sensitivity analysis. Average age at treatment initiation was 50, 54% were female, 47% were biologic treatment naïve, and 39% had skin PsO. In the multivariate main analysis, UST exhibited lower discontinuation rates vs ADA (HR=0.56, 95% CI: 0.49-0.64) while there was no significant difference between SEC and ADA (HR=1.01, 95% CI: 0.88-1.15). In the multivariate sensitivity analysis, both UST (HR=0.81, 95% CI: 0.70-0.94) and SEC (HR=0.82, 95% CI: 0.70-0.95) were associated with significantly lower discontinuation rates ratio relative to ADA. Overall, patients with more biologic treatment experience were statistically significantly (p<0.05) associated with higher risk of treatment discontinuation.

Figure 1.

Unadjusted Kaplan-Meier curves of time to treatment discontinuation (main analysis, dynamic grace period)

Conclusion:

UST exhibits a favourable treatment persistency profile relative to ADA, regardless of the grace period definition. The relative risk of discontinuing SEC vs ADA is sensitive to the grace period. Treatment discontinuation was higher in treatment exposures with more biologic experience.

Disclosure of Interests:

Kirk Geale Consultant of: Quantify Research, Speakers bureau: Indirectly as a consultant, Ingrid Lindberg Consultant of: Quantify Research, Emma Paulsson Consultant of: Quantify Research, Christina Wennerström Employee of: Janssen-Cilag Sweden AB, Anna Tjärnlund Employee of: Janssen-Cilag Sweden AB, Virginia Taliadouros Shareholder of: JnJ, Employee of: Janssen Pharmaceuticals NV, Wim Noel Employee of: Janssen Pharmaceuticals NV, Dana Enkusson Employee of: Janssen-Cilag AB, Elke Theander Employee of: Janssen-Cilag Sweden AB, Sara Bruce Wirta Employee of: Janssen-Cilag Sweden AB

TIMFIE Sampler-A New Time-Integrating, Active, Low-Tech Sampling Device for Quantitative Monitoring of Pesticides in Whole Water

The need for inexpensive, time-averaged, quantitative determination of pesticides and other organic pollutants in whole water is not matched by the field sampling procedures available. Our new Time-Integrating, MicroFlow, In-line Extraction (TIMFIE) sampler comprises a low-tech syringe pump driven by a rubber band and connected to a flow restrictor enabling low microliter per minute water flow through a solid phase extraction (SPE) cartridge. This allows target compounds to be continuously extracted in the field over 1 week. The extracted water ends up in the syringe, where sample volume is accurately determined. TIMFIE followed by online SPE-LC-MS/MS determination was validated for 72 selected pesticides, and, except for three compounds, detection limit was 0.1-1 ng/L. In a field study, concentrations in TIMFIE samples and in grab samples were compared. Following TIMFIE sampling, on average 19 pesticides per sample were quantified, compared with nine pesticides per sample with grab sampling, as a result of the extra in-field concentration step. Duplicate TIMFIE sampling showed Pearson's correlation coefficient r = 0.998. Comparing concentrations from TIMFIE sampling to grab sampling resulted in ratios between 0.05 and 16.5 (mean 1.7; r = 0.532), demonstrating a discrepancy between the two sampling strategies and possible underestimation of chronic exposure by grab sampling.

Pesticides from wastewater treatment plant effluents affect invertebrate communities

We quantified pesticide contamination and its ecological impact up- and downstream of seven wastewater treatment plants (WWTPs) in rural and suburban areas of central Germany. During two sampling campaigns, time-weighted average pesticide concentrations (c_TWA) were obtained using Chemcatcher® passive samplers; pesticide peak concentrations were quantified with event-driven samplers. At downstream sites, receiving waters were additionally grab sampled for five selected pharmaceuticals. Ecological effects on macroinvertebrate structure and ecosystem function were assessed using the biological indicator system SPEAR_pesticides (SPEcies At Risk) and leaf litter breakdown rates, respectively. WWTP effluents substantially increased insecticide and fungicide concentrations in receiving waters; in many cases, treated wastewater was the exclusive source for the neonicotinoid insecticides acetamiprid and imidacloprid in the investigated streams. During the ten weeks of the investigation, five out of the seven WWTPs increased in-stream pesticide toxicity by a factor of three. As a consequence, at downstream sites, SPEAR values and leaf litter degradation rates were reduced by 40% and 53%, respectively. The reduced leaf litter breakdown was related to changes in the macroinvertebrate communities described by SPEAR_pesticides and not to altered microbial activity. Neonicotinoids showed the highest ecological relevance for the composition of invertebrate communities, occasionally exceeding the Regulatory Acceptable Concentrations (RACs). In general, considerable ecological effects of insecticides were observed above and below regulatory thresholds. Fungicides, herbicides and pharmaceuticals contributed only marginally to acute toxicity. We conclude that pesticide retention of WWTPs needs to be improved.

Influence of culture conditions on porphyrin production in Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis

BACKGROUND

Increasing antibiotic resistance among pathogens has raised the demands for new treatment methods such as antimicrobial photodynamic therapy (aPDT) and phototherapy (PT). Experiments for investigating the effects of these methods are often performed in vitro, but the procedures for cultivation of microbes vary between different studies. The aim of this study has been to elucidate how the profile of endogenously produced porphyrins differs by changing the variables of bacteria culturing conditions.

METHODS

Two oral pathogens, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, were selected as model organisms. The contents of porphyrins and heme in the bacteria were analysed with liquid chromatography-tandem mass spectrometry when bacteria was cultivated for different lengths of time (3-9 days), upon passaging as well as when growth medium were supplemented with or without horse blood.

RESULTS

Both porphyrin and heme content in A. actinomycetemcomitans are highly affected by the age of the culture, and that the porphyrin profiles changes during cultivation. When cultivated colonies of A. actinomycetemcomitans were passaged onto a new, fresh growth medium a large change in porphyrin content occurred. Additional porphyrins were detected; uroporphyrin and 7-carboxylporphyrin, and the total porphyrin content increased up to 28 times. When P. gingivalis was grown on blood containing medium higher concentrations of protoporphyrin IX (2.5 times) and heme (5.4 times) were quantified compared to bacteria grown without blood.

CONCLUSIONS

This study demonstrate that there is a need for more standardized culturing protocols when performing aPDT and PT experiments in vitro to avoid large variations in porphyrin profiles and concentrations, the aPDT/PT target compounds, depending on the culturing conditions.