Progress of Essure Birth Control Implant Post-Marketing Study “Inadequate,” FDA Warns Bayer

Nearly half of participants have discontinued the Essure birth control implant post-marketing study, causing massive losses in follow-up data, the FDA warns.

The U.S. Food and Drug Administration (FDA) required Bayer to conduct post marketing research on side effects of Essure birth control implants, following thousands of reports involving complications among women who had the coils implanted. However, the agency recently described progress of the study “inadequate”, due to a high rate of dropouts among participants.

Essure was marketed by Bayer for years as a safe and effective form of permanent birth control, involving flexible coils inserted into the Fallopian tubes during an outpatient procedure. It is intended to cause scar tissue to develop, which blocks the tubes and prevents insemination. However, the device was removed from the market in 2018, following thousands of reports involving painful and debilitating Essure complications.

Following the device’s removal from the market, Bayer was ordered to conduct post-marketing surveillance of women who had received the implant, to get a better sense of the likely adverse health effects of the birth control device.

In the latest FDA Essure update issued on October 6, the agency announced that it is changing the post-marketing surveillance study’s status to “Progress Inadequate,” because of dropping follow-up rates among subjects who either received Essure implants or who underwent laparoscopic tubal sterilization (LTS), which is the group being used as a comparison to determine Essure complication and efficacy rates.

The patients enrolled in the study were supposed to complete 36-month, 48-month, and 60-month follow-up visits. However, according to a report on the FDA’s Postmarket Surveillance Studies Database, too many enrolled patients in both groups are discontinuing, resulting in poor quality follow-up data.

The FDA found that 47.4% of the Essure patients, or 161 out of 340, have discontinued the study, with 29%, or 100 patients, due to lost follow-up. Of the LTS patients, 43.6%, or 344 out of 790 enrolled in the study, have discontinued, with a third due to lost follow-up.

“The FDA changed the study status to ‘progress inadequate’ due to the increase in interim lost to follow-up rates in both groups from the previous database lock in 2021,” the report states. “’Progress Inadequate’ means that the progress of the study is not consistent with the study plan.”

FDA Calls on Bayer to Develop New Essure Post-Market Surveillance Strategies

The FDA indicates some of the loss in follow-up rates in both groups could be attributed to the COVID-19 pandemic. The FDA has informed Bayer it needs to develop and implement additional strategies to improve follow-up rates.

The next interim analysis of the data will be completed after all patients have finished three years of follow-up, and a final analysis will be done after all patients have completed five years of follow-up. However, that data could be unreliable if the number of patients discontinuing is not somehow addressed.

In an an update on Essure adverse event and product problem reports  issued in March, the FDA indicated it has received a total of 67,643 medical device reports linked to the Essure implant. While most reports received between 2013 and 2015 were voluntary submissions from women who received Essure implants, last year 98% of the 3,701 reports received by the FDA were submitted by Bayer. Of those, 85% were related to device removal, the FDA noted, and most were linked to litigation.

Bayer faced tens of thousands of Essure lawsuits filed by women who experienced adverse health effects while implanted with the birth control device.

After several years of litigation, the company announced in 2020 that it would pay $1.6 billion to settle about 90% of all Essure cases pending at that time. However, with approximately 750,000 women worldwide implanted with the device, and 70% of those Essure procedures occurring in the United States, it is expected that additional lawsuits will be filed in the coming years as women continue to experience complications.