Comparative Effectiveness and Safety of Trastuzumab Biosimilars to Herceptin for Adjuvant Treatment of HER2+ Breast Cancer.

Background: Ontario publicly funds reference trastuzumab (Herceptin) and four biosimilar trastuzumab products for adjuvant treatment of HER2+ breast cancer. We assessed the real-world safety and effectiveness of biosimilar trastuzumab compared to Herceptin for adjuvant treatment of patients with HER2+ breast cancer. Methods: This was a population-based, retrospective study comparing the safety and effectiveness of biosimilar trastuzumab and Herceptin for neoadjuvant/adjuvant treatment of HER2+ breast cancer from 2016 to 2021. Treatment patients started biosimilar trastuzumab from November 2019 to June 2021; historical comparator patients started Herceptin from June 2016 to October 2019. Safety outcomes death within 30 days of last dose of trastuzumab, direct hospitalization, emergency department visit leading to hospitalization, early treatment discontinuation, and in-patient admission for congestive heart failure were measured using logistic/negative binomial regression. Overall survival (OS) was measured using Kaplan-Meier methods and Cox proportional hazards regression. Propensity score matching was applied. Results: From June 2016 to 2021, 5071 patients with breast cancer were treated with neoadjuvant/adjuvant trastuzumab. The rate of direct hospitalization (RR: 0.85, 95% CI: 0.74-0.98, p-value: 0.032) was significantly lower in biosimilar compared to Herceptin patients. OS (log-rank test p = 0.98) and risk of mortality (HR: 1.29, 95% CI: 0.72-2.30, p-value = 0.39) did not significantly differ between treatment groups. Conclusions: Biosimilar trastuzumab demonstrated similar safety and effectiveness to Herceptin. The findings can help improve confidence in and use of biosimilars and demonstrate the value of real-world evidence generation for supporting biosimilar implementations and reassessments.

Comparison of Use of Neoadjuvant Systemic Treatment for Breast Cancer and Short-term Outcomes Before vs During the COVID-19 Era in Ontario, Canada.

Importance: In response to an increase in COVID-19 infection rates in Ontario, several systemic treatment (ST) regimens delivered in the adjuvant setting for breast cancer were temporarily permitted for neoadjuvant-intent to defer nonurgent breast cancer surgical procedures. Objective: To examine the use and compare short-term outcomes of neoadjuvant-intent vs adjuvant ST in the COVID-19 era compared with the pre-COVID-19 era. Design, Setting, and Participants: This was a retrospective population-based cohort study in Ontario, Canada. Patients with cancer starting selected ST regimens in the COVID-19 era (March 11, 2020, to September 30, 2020) were compared to those in the pre-COVID-19 era (March 11, 2019, to March 10, 2020). Patients were diagnosed with breast cancer within 6 months of starting systemic therapy. Main Outcomes and Measures: Estimates were calculated for the use of neoadjuvant vs adjuvant ST, the likelihood of receiving a surgical procedure, the rate of emergency department visits, hospital admissions, COVID-19 infections, and all-cause mortality between treatment groups over time. Results: Among a total of 10 920 patients included, 7990 (73.2%) started treatment in the pre-COVID-19 era and 7344 (67.3%) received adjuvant ST; the mean (SD) age was 61.6 (13.1) years. Neoadjuvant-intent ST was more common in the COVID-19 era (1404 of 2930 patients [47.9%]) than the pre-COVID-19 era (2172 of 7990 patients [27.2%]), with an odds ratio of 2.46 (95% CI, 2.26-2.69; P < .001). This trend was consistent across a range of ST regimens, but differed according to patient age and geography. The likelihood of receiving surgery following neoadjuvant-intent chemotherapy was similar in the COVID-19 era compared with the pre-COVID-19 era (log-rank P = .06). However, patients with breast cancer receiving neoadjuvant-intent hormonal therapy were significantly more likely to receive surgery in the COVID-19 era (log-rank P < .001). After adjustment, there were no significant changes in the rate of emergency department visits over time between patients receiving neoadjuvant ST, adjuvant ST, or ST only during the ST treatment period or postoperative period. Hospital admissions decreased in the COVID-19 era for patients who received neoadjuvant ST compared with adjuvant ST or ST alone (P for interaction = .01 for both) in either setting. Conclusions and Relevance: In this cohort study, patients were more likely to start neoadjuvant ST in the COVID-19 era, which varied across the province and by indication. There was limited evidence to suggest any substantial impact on short-term outcomes.

The Association of Drug-Funding Reimbursement With Survival Outcomes and Use of New Systemic Therapies Among Patients With Advanced Pancreatic Cancer.

Importance: Gemcitabine-nab-paclitaxel (GEMNAB) and fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) both improve survival of patients with advanced pancreatic cancer when compared with single-agent gemcitabine in clinical trials. Objective: To describe changes in the survival of patients with advanced pancreatic cancer associated with sequential drug-funding approvals and to determine if there exist distinct patient populations for whom GEMNAB and FOLFIRINOX are associated with survival benefit. Design, Setting, and Participants: This population-based, retrospective cohort study examined all incident cases of advanced pancreatic cancer treated with first-line chemotherapy in Ontario, Canada (2008-2018) that were identified from the Cancer Care Ontario (Ontario Health) New Drug Funding Program database. Statistical analysis was performed from October 2020 to January 2021. Exposures: First-line chemotherapy for advanced pancreatic cancer. Main Outcomes and Measures: The main outcomes were the proportion of patients treated with each chemotherapy regimen over time and overall survival for each regimen. Cox proportional hazards regression models were used to compare overall survival between treatment regimens after adjustment for confounding variables, inverse probability of treatment weighting, and matching. Results: From 2008 to 2018, 5465 patients with advanced pancreatic cancer were treated with first-line chemotherapy in Ontario, Canada. The median (range) age of patients was 66.9 (27.8-93.4) years; 2447 (45%) were female; 878 (16%) had prior pancreatic resection, and 328 (6%) had prior adjuvant gemcitabine. During the time period when only gemcitabine and FOLFIRINOX were funded (2011-2015), 49% (929 of 1887) received FOLFIRINOX. When GEMNAB was subsequently funded (2015-2018), 9% (206 of 2347) received gemcitabine, 44% (1034 of 2347) received FOLFIRINOX, and 47% (1107 of 2347) received GEMNAB. The median overall survival increased from 5.6 months (95% CI, 5.1-6.0 months) in 2008 to 2011 to 6.9 months (95% CI, 6.5-7.4 months) in 2011 to 2015 to 7.6 months (95% CI, 7.1-8.0 months) in 2015 to 2018. Patients receiving FOLFIRINOX were younger and healthier than patients receiving GEMNAB. After adjustment and weighting, FOLFIRINOX was associated with better overall survival than GEMNAB (hazard ratio [HR], 0.75 [95% CI, 0.69-0.81]). In analyses comparing patients treated with GEMNAB and gemcitabine, GEMNAB was associated with better overall survival (HR, 0.86 [95% CI, 0.78-0.94]). Conclusions and Relevance: This cohort study of patients with advanced pancreatic cancer receiving first-line palliative chemotherapy within a universal health care system found that drug funding decisions were associated with increased uptake of new treatment options over time and improved survival. Both FOLFIRINOX and GEMNAB were associated with survival benefits in distinct patient populations.

Comparison of response rates on invitation mode of a web-based survey on influenza vaccine adverse events among healthcare workers: a pilot study.

BACKGROUND: Web-based surveys have become increasingly popular but response rates are low and may be prone to selection bias. How people are invited to participate may impact response rates and needs further study as previous evidence is contradictory. The purpose of this study was to determine whether response to a web-based survey of healthcare workers would be higher with a posted or an emailed invitation. We also report results of the pilot study, which aims to estimate the percentage of adults vaccinated against influenza who report recurrent systemic adverse events (the same systemic adverse event occurring successively following receipt of influenza vaccines). METHODS: The pilot study was conducted in November 2016 in Toronto, Canada. Members of a registry of adults (18 years and older and predominantly healthcare workers) who volunteered to receive information regarding future studies about influenza were randomly assigned to receive either an email or postal invitation to complete a web-based survey regarding influenza vaccinations. Non-respondents received one reminder using the same mode of contact as their original invitation. RESULTS: The overall response rate was higher for those sent the invitation by email (34.8%) than by post (25.8%; p < 0.001) and for older versus younger participants (ptrend < 0.001). Of those who responded, 387/401 had been vaccinated against influenza at least once since adulthood. Of those responding to the question, 70/386 (18.1%) reported a systemic adverse event after their most recent influenza vaccine including 22 (5.7%) who reported a recurring systemic event. Systemic adverse events were reported more often by males 18-49 years old than by other groups (p = 0.01). Recurrent systemic adverse events were similar by age and sex with muscle ache being the most commonly reported recurrent reaction. More respondents who reported only a local adverse event (93.1%) planned to be vaccinated again next year than those with a systemic adverse event (69.7%; p = 0.04). CONCLUSIONS: In this convenience sample of registry volunteers, response rates were generally low, but were higher for the emailed than posted invitations and for older than younger adults.

Urinary bisphenol A concentrations positively associated with glycated hemoglobin and other indicators of diabetes in Canadian men.

BACKGROUND: Bisphenol A (BPA), an endocrine disrupting chemical (EDC), may pose a risk to human health, including diabetes. However, epidemiological studies from the U.S., China and South Korea showed inconsistent results. OBJECTIVE: To examine the associations between BPA and indicators of diabetes in the general Canadian population. METHODS: The analysis was based on cross-sectional data from the Canadian Health Measures Survey (CHMS) Cycle 2 (2009-2011). We included 1915 participants with glycated hemoglobin (HbA1c) measurement and 2405 participants with serum glucose (SG) measurement aged 3-79 years, respectively. Multiple linear regression analyses were performed to model HbA1c and log-transformed SG levels associated with quartiles of urinary BPA concentrations controlling for potential confounders. Further, in adults (age≥18 years), logistic regression analysis was conducted to evaluate the association between BPA and physician-diagnosed diabetes mellitus (DM). Bootstrap weights were applied to all the analyses to account for the complex survey design. RESULTS: The geometric mean of urinary BPA was 1.21 (±0.05)µg/L. Overall, a positive association was observed between urinary BPA quartiles and HbA1c levels in men after controlling for potential confounders (P<0.05), but not in women and children. Similar patterns were found for the associations of BPA with log-transformed SG levels and doctor-diagnosed DM. CONCLUSIONS: Higher urinary BPA levels were associated with adverse glucose homeostasis in Canadian men, independent of major covariates. Prospective studies with longitudinal design are needed to further investigate the causality.