- A postmarket surveillance study has linked Bayer’s Essure birth-control implant to a numerically higher rate of some safety outcomes than laparoscopic tubal sterilization (LTS).
- The latest interim analysis of the study, which the Food and Drug Administration asked Bayer to run, shows trends seen in previous years persisted. Rates of gynecologic surgical procedures and endometrial ablation were numerically higher in the Essure group.
- Bayer has acted on the FDA’s request for actions to improve follow-up rates in the study, leading the administration to remove the “inadequate” progress tag it applied to the trial last year.
The origins of the postmarket surveillance study date back to 2016, when the FDA asked Bayer to collect data on the device. Bayer stopped selling the device in the U.S. two years later, framing the action as a business decision rather than a reflection of the safety of a product that was the subject of tens of thousands of reports of complications, including reports of injuries and deaths.
While the withdrawal prevented Bayer from hitting the enrollment target in its postmarket surveillance study, the company has continued to collect data on the 1,130 patients it recruited at 60 investigational sites in the U.S.
The FDA on Monday published an analysis of the data as of March 10.
The findings of the 2023 interim analysis are in line with the results of earlier looks at the data. The overall adjusted incidence of patients undergoing gynecologic surgical procedures after the sterilization procedures remains higher in the Essure group (23.9%) than the LTS arm (7.6%). The gap between the arms, which is unchanged from the 2020 analysis, is driven by device removals and endometrial ablation.
There was also a higher instance of chronic lower abdominal and/or pelvic pain in the Essure group (14.4%) than in the LTS group (10.2%), and similar rates of reports of abnormal uterine bleeding for Essure (21.6%) and LTS (20.8%). Both categories are among the main safety endpoints of the study, along with gynecological surgical procedures.
Officials used the 2023 analysis to reassess the status of the study. Last year, the FDA said progress was “inadequate” because the rate of participants lost to follow-up had increased. The proportion of subjects who have discontinued the study has risen from one-third to half since the 2022 analysis, but the FDA is satisfied with Bayer’s efforts to reduce the proportion of participants lost to follow-up.
“Since 2022, Bayer has taken measures to reduce interim lost to follow-up rates at 3 years in both groups. The current study status is now ‘ongoing’ because the progress of the study is consistent with the study plan. The FDA will continue to closely monitor lost to follow-up rates in the study and work with Bayer to take additional measures as needed,” the FDA wrote.
The agency also made a change to its information about Essure for patients and healthcare providers in relation to the updated data. Officials deleted a line about the timing of the interim analysis and clarified when the final analysis will happen. In the updated text, the FDA states final analyses of endpoints will happen after all patients have completed five years of follow-up.