FLIP-2: A placebo-controlled double blinded randomised trial to assess the safety and efficacy of LACTIN-V, a live biotherapeutic Lactobacillus crispatus strain CTV-05, in reducing the risk of preterm labour in a cohort of women predefined as at high risk
Preterm labour
LACTIN-V is supplied as a pre-filled, single-use vaginal applicator. Each applicator contains 200 mg of LACTIN-V powder at a dose of 2 x 109 CFU. The LACTIN-V powder formulation contains L. crispatus CTV-05, trehalose, xylitol, sodium ascorbate, colloidal silicon dioxide, and maltodextrin. The placebo for this trial will consist of an identical appearing inert powder delivered via the same single-use applicator. The study drug will be administered as an initial loading phase followed by a maintenance phase. The first five doses will occur on five consecutive days, which is referred to the ‘loading phase’. Further single doses will be given at once-weekly intervals (calculated 1 week from the 5th consecutive dose) up to the 34th week of pregnancy. This is referred to as the ‘maintenance phase’. Participants are randomised using Sealed Enveloped incorporated into the OpenClinica eCRF system. All participants are followed up until the birth of their baby. At 24 months of age, parents will be invited to complete the online PARCA-R questionnaire, which serves as a tool of assessing developmental outcomes in children.
1. Women confirmed to be at risk of preterm labour, as defined by previous preterm birth and/or mid trimester loss 2. Able to provide written, informed consent 3. Confirmed viable intrauterine singleton pregnancy between 12-16 weeks gestational age
Current key exclusion criteria as of 24/02/2026: 1. Women living with HIV 2. Women under the age of 17 years (updated 23/01/2026, previously under the age of 18 years) 3. Women with a multiple pregnancy 4. Known allergy or sensitivity to the investigational product 5. Participants taking part in an alternative interventional research study 6. Known congenital/structural or chromosomal anomaly in the fetus 7. Women with deep epithelial disruption observed on genital examination on or before the day of randomisation 8. Women with any condition requiring regular periodic use of systemic antibiotics during participation in the trial 9. Women with any social, medical, or psychiatric condition that in the opinion of the Investigator would complicate the evaluation or make it unlikely for the subject to comply with the study protocol 10. Use of immunosuppressive drugs within 60 days of randomisation 11. Women who are lactating. Previous key exclusion criteria: 1. Women living with HIV 2. Women under the age of 17 years (updated 23/01/2026, previously under the age of 18 years) 3. Women with a multiple pregnancy 4. Known allergy or sensitivity to the investigational product 5. Participants taking part in an alternative interventional research study 6. Known congenital/structural or chromosomal anomaly 7. Women with deep epithelial disruption observed on genital examination on or before the day of randomisation 8. Women with any condition requiring regular periodic use of systemic antibiotics during participation in the trial 9. Women with any social, medical, or psychiatric condition that in the opinion of the Investigator would complicate the evaluation or make it unlikely for the subject to comply with the study protocol 10. Use of immunosuppressive drugs within 60 days of randomisation