GlaxoSmithKline (GSK) said it has stopped enrollment in three phase 3 trials evaluating its respiratory syncytial virus vaccine (RSV) in pregnant women pending further analysis of safety data.

The British drugmaker paused the trials last week, following a recommendation from the independent data monitoring committee after a routine safety assessment. However, GSK has not said what those safety findings were.

GSK said it will continue a phase 3 clinical trial for RSV in adults who are 60 years and up. Results from that trial are expected during the first half of this year.