Objectives: HIV pre-exposure prophylaxis (PrEP) is a proven tool for HIV prevention, but PrEP use in Ontario, Canada, and the effects of recent policies are unknown. We estimated the number and characteristics of PrEP users in Ontario and evaluated the impacts of policy changes between July 2015 and June 2018. Methods: We obtained tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) dispensation data for Ontario from IQVIA, and applied an algorithm to identify use for PrEP. We report prevalent PrEP use for the second quarter of 2018 according to age, sex, region, prescriber specialty, and payer type, and generate “PrEP-to-need ratios” (PNR) by dividing these numbers by the estimated numbers of new HIV diagnoses. We used interventional autoregressive integrated moving average models to examine the impact of three policy changes on PrEP use: Health Canada approval (February 2016), availability of generic TDF/FTC and partial public drug coverage (September 2017), and public drug coverage for individuals aged < 25 years (January 2018). Results: The estimated number of individuals receiving PrEP increased 713%, from 374 in 2015 Q3 to 3041 in 2018 Q2. Among PrEP users in 2018 Q2, 97.5% were male, 60.4% were < 40 years, 67.7% obtained PrEP from a family physician, 77.2% used private insurance, and 67.0% were in Toronto. PNRs were highest in 30–39-year-olds, males, Toronto and the Central East and West regions. Time series analyses found that Health Canada approval (p = 0.0001) and introducing generics/partial public drug coverage (p = 0.002) led to significantly increased use. Conclusions: PrEP use has risen in Ontario in association with favourable policy changes, but remains far below guideline recommendations.

Purpose: High‐strength opioid formulations were delisted (removed) from Ontario's public drug formulary in January 2017, except for palliative patients. We evaluated the impact of this policy on opioid utilization and dosing.Methods: We conducted a longitudinal study among patients receiving publicly funded, high‐strength opioids from August 2016 to July 2017. The primary outcome measure was weekly median daily opioid dose (in milligrams of morphine or equivalent; MME) of (1) publicly funded and (2) all opioid prescriptions irrespective of funding source, evaluated using interrupted time series analyses and stratified by palliative care status.Results: Following policy implementation, the weekly median daily dose of publicly funded opioids decreased immediately among non‐palliative patients by 10 MME (95% confidence limit [CL], −16.8 to −3.1) from a pre‐intervention dose of 424.5 MME (95% CL, 417.8‐431.2) and fell gradually among palliative patients by 3.9 MME per week (95% CL, −5.5 to −2.3) from a pre‐intervention dose of 450.1 MME (95% CL, 432.5‐467.7). In contrast, among all opioid prescriptions, gradual reductions in weekly median daily doses were observed only for non‐palliative patients, which decreased by 0.7 MME per week (95% CL, −1.3 to −0.2) from a pre‐intervention dose of 426.2 MME (95% CL, 420.9‐431.5).Conclusion: The delisting of publicly‐funded, high‐strength opioids was accompanied by changes in funding source and small reductions in the weekly median daily doses dispensed. Although observed dose reductions of less than 1 MME weekly are likely not clinically relevant, safety implications of these changes require further monitoring.

Introduction Ontario delisted high-strength fentanyl, hydromorphone and morphine from the public drug formulary for non-palliative care prescribers on 31 January, 2017. Our aim is to assess the early impact of this policy on prescribing patterns and to examine whether this impact varied by prescriber type, opioid type and opioid strength. Methods We conducted a population-based, cross-sectional study on palliative and non-palliative care patients dispensed fentanyl, hydromorphone or morphine through the Ontario public drug program between 1 January, 2014, and 31 July, 2017. For each month during the study period, we reported the total number of high-strength opioid recipients stratified by prescriber type, and the total volume of each drug dispensed, stratified by strength. We used interventional autoregressive integrated moving average (ARIMA) models to assess the policy’s impact on prescribing patterns. Results We observed a 98% decrease in the total number of publicly funded recipients of high-strength opioids between December 2016 and July 2017 (5930 to 133 recipients) for all prescribers. The policy led to a significant decline in the total volume of all three opioids dispensed: hydromorphone from 20 374 621 to 16 952 097 mg (p $lt; .01); morphine from 40 644 190 to 33 555 480 mg (p $lt; .03); and fentanyl from 9 604 913 to 5 842 405 mcg/h (p $lt; .01). For both fentanyl and hydromorphone, this reduction generally corresponded to an increase in the number of low-strength opioids dispensed. Conclusion Delisting high-strength opioids substantially reduced the number of highstrength opioid recipients and reduced the overall volume of long-acting opioids dispensed in Ontario through the public drug program. Future studies should examine its impact on patient outcomes.

Endometrial cancer (EC) incidence has increased in recent decades. However, population-based outcomes data are limited. In this retrospective cohort study, we examined characteristics, treatment patterns, and clinical outcomes, including time to next treatment (TNNT) and overall survival (OS), among advanced/recurrent (A/R) EC patients between 2010 and 2018 in Alberta, Canada. Kaplan–Meier statistics evaluated TTNT and OS, stratified by patient (A/R) and treatment. A total of 1053 patients were included: 620 (58.9%) advanced and 433 (41.1%) recurrent. A total of 713 (67.7%) patients received first-line therapy: 466 (75.2%) advanced and 247 (57.0%) recurrent. Platinum-based chemotherapy (PBCT) was the most common first-line regimen (overall: 78.6%; advanced: 96.1%; recurrent: 45.3%). The median TTNT and OS from first-line therapy were 19.9 months (95% confidence interval [CI]: 17.5–23.5) and 35.9 months (95% CI: 31.5–53.5), respectively. Following first-line PBCT, the median OS from second-line chemotherapy (N = 187) was 10.4 months (95% CI: 8.9–13.3) and higher for those rechallenged with PBCT (N = 72; 38.5%) versus no rechallenge (N = 115; 61.5%) (13.3 months [95% CI: 11.2–20.9] vs. 6.4 months [95% CI: 4.6–10.4; p < 0.001]). The findings highlight poor outcomes in A/R EC, particularly following first-line therapy, and that additional tolerable therapeutic options are needed to improve patient outcomes.

E17624 Background: Endometrial cancer (EC) incidence in Canada is steadily increasing and a paucity of real-world data exists. This study aimed to examine treatment (tx) patterns and clinical outcomes for patients (pts) with advanced and recurrent (A/R) EC in Canada. Methods: A retrospective observational cohort study was conducted among pts with primary advanced EC (de novo stage IIIB, IIIC, IV) or recurrent EC (progression from de novo stage I, II, IIIA) between 2010 and 2018 in Alberta, Canada. Health administrative data were used to describe baseline characteristics, time to next tx (TTNT), and overall survival (OS). Using Kaplan-Meier methods, TTNT was defined from tx initiation to initiation of subsequent tx or death from any cause, and OS was examined from tx initiation until death from any cause. Outcomes were stratified by pt type (A/R) and tx. Results: 1,053 pts were included: 620 (58.9%) advanced and 433 (41.1%) recurrent pts. 713 (67.7%) pts received first-line (1L) systemic therapy; this differed by pt type (75.2% of advanced and 57.0% of recurrent pts). Advanced pts who received chemotherapy were more likely to have prior surgery (p < 0.001), radiotherapy (p = 0.01), were younger (p < 0.001), and had fewer comorbidities (p < 0.001) than those without chemotherapy. Platinum-based chemotherapy (PBCT) was the most common 1L regimen (78.6%), differing by pt type (96.1% for advanced and 45.4% for recurrent pts). Hormone therapy in 1L was higher for recurrent compared to advanced pts (27.9% vs 3.2%). Median TTNT and OS from 1L systemic therapy was 19.9 months (95% confidence interval [CI]: 17.5–23.5) and 35.9 months (95% CI: 31.5–53.5), differing by therapy (p < 0.05). Median OS from 1L ranged from 8.5 months (95% CI: 6.2–20.0; platinum monotherapy) to 62.5 months (95% CI: 59.2–NA; hormone therapy). 257 pts received second-line (2L) chemotherapy, with a median TTNT of 7.0 months (95% CI: 6.1–8.2) and median OS of 12.6 months (95% CI: 10.0–14.6). Outcomes differed by tx (p < 0.05), with median OS ranging from 8.0 months (95% CI: 5.9–13.2; non-platinum monotherapy) to 17.1 months (95% CI: 12.7–NA; non-platinum combination). Among pts who received a 1L PBCT, median OS from 2L chemotherapy (N = 187) was 10.4 months (95% CI: 8.9–13.3) and was significantly higher for those rechallenged with PBCT compared to no rechallenge (13.3 months [95% CI: 11.2–20.9] vs 6.4 months [95% CI: 4.6–10.4]). Median OS in third-line (N = 71) and fourth-line (N = 26) chemotherapy was 11.0 months (95% CI: 8.2–13.5) and 12.0 months (95% CI: 7.5–NA), respectively. Outcomes did not differ significantly by pt type (A/R; p≥0.05). Conclusions: Outcomes for pts with A/R EC in Alberta, Canada are poor, particularly following 1L therapy where tx options are limited. Novel therapies with proven efficacy could address this unmet need and improve pt outcomes. Funding: GSK (216962; diana.d.martins@gsk.com).

Objectives: Interstitial lung disease (ILD) is a pulmonary manifestation of connective tissue diseases (CTDs). Limited data exist describing the epidemiology of CTD-ILD; therefore, this study aimed to estimate the incidence and prevalence of CTD-ILD in the US, overall and by CTD-ILD subtypes. Methods: Patients with CTD-ILD and rheumatoid arthritis (RA), systemic sclerosis (SSc), systemic lupus erythematosus (SLE), idiopathic inflammatory myopathy (IIM), mixed CTD (MCTD), and Sjögren’s disease (SjD) were identified from Optum ^® de-identified Electronic Health Record data set (Optum ^® EHR) and MarketScan ^® Commercial and Medicare US databases between 2019 and 2024. Results: ILD was present in 4.3% (n = 21,366/496,690; Optum ^® EHR) and 3.2% (n = 7521/234,468; MarketScan) of identified patients with CTD. This proportion was highest for those with SSc (Optum ^® EHR: 20.3%; MarketScan: 21.1%). Most patients with CTD-ILD were female in both Optum ^® EHR and MarketScan, with median ages 64 and 56 years, respectively; race was available only in Optum ^® EHR, where 72.1% were categorized as Caucasian. Age- and sex-adjusted incidence rates were 7.6 and 10.0 per 100,000 person-years, with adjusted prevalence rates 46.7 and 43.4 per 100,000 persons. Rates varied by CTD subtype and were highest for RA-ILD and lowest for MCTD-ILD across databases. Crude rates of CTD-ILD regardless of subtype were higher among female patients, patients aged ≥ 65 years, and among patients of Black African ancestry. Conclusion: Consistent age- and sex-adjusted CTD-ILD incidence and prevalence estimates between two large, demographically distinct US databases provide contemporary population-level estimates of CTD-ILD frequency and distribution that can inform disease screening and patient care. Key points • US CTD-ILD incidence estimated at 7.6 and 10.0/100,000 person-years and prevalence estimated at 46.7 and 43.4/100,000 persons. • Incidence and prevalence rates were highest in female patients, patients aged ≥ 65 years, and patients of Black African ancestry. • Incidence and prevalence rates varied between CTD subtypes and were highest for RA-ILD and lowest for MCTD-ILD.