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Not yet recruitingNCT07888699Updated Oct 22, 2026

WST03 Capsule Combined With Metronidazole for Bacterial Vaginosis

A Phase 2 interventional study of High-dose WST03 Vaginal Capsule Metronidazole and Low-dose WST03 Vaginal Capsule Metronidazole in Bacterial Vaginosis (BV), sponsored by SPH Sine Pharmaceutical Laboratories Co., Ltd.. Not yet recruiting at 14 sites in China. Open to female participants aged 18 Years to 55 Years. Per ClinicalTrials.gov, last updated 2026-10-22.

Sponsored by SPH Sine Pharmaceutical Laboratories Co., Ltd. · Phase 2, Interventional, and Treatment

Updated Oct 22, 2026Newly registeredGo to Updates ↓
Phase
Phase 2
Study type
Interventional
Enrollment
150
Allocation
Randomized
Ages
18 Years to 55 Years
Sex
Female
01

Study summary

This is a multicenter, randomized, double-blind, placebo-controlled Phase 2 trial enrolling approximately 150 pre-menopausal women with bacterial vaginosis (BV). Participants will be randomized 1:1:1 to three groups. All participants will receive oral metronidazole 0.4 g twice daily for 7 days. In addition, participants will take vaginal capsules (high-dose WST03, low-dose WST03, or matched placebo) once daily for 14 days. The primary endpoint is cumulative BV recurrence rate at Week 12. This trial evaluates the efficacy and safety of WST03 plus metronidazole for lowering BV recurrence and explores its impact on vaginal microecology.

02

Conditions studied

  • Bacterial Vaginosis (BV)

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03

In context

Vaginosis, Bacterial

228 studies on the registry are indexed under Vaginosis, Bacterial; 39 are open to participants now.

This study's planned enrollment of 150 is above the median of 100 across 194 interventional studies indexed under Vaginosis, Bacterial.

Browse Vaginosis, Bacterial studies →

Lead sponsor

SPH Sine Pharmaceutical Laboratories Co., Ltd. is the lead sponsor of 2 studies on the registry; 1 is open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 55 Years
Sexes eligible
Female
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Pre-menopausal female aged 18-55 years inclusive.
  2. Regular menstrual cycle of 21-35 days.
  3. Clinically diagnosed bacterial vaginosis: at least 3 of 4 Amsel criteria positive with mandatory clue-cell positive; screening Nugent score ≥7.
  4. No prior treatment for current episode of BV.
  5. Sexually active history; willing for vaginal drug administration; agree to avoid prohibited vaginal products and comply with sexual activity restrictions per protocol.
  6. No pregnancy plan during study and within 3 months after last study dose, agree to use effective barrier contraception.
  7. Voluntarily sign informed consent form and be able to comply with all study procedures.

Exclusion criteria

Exclusion Criteria:

  1. Current pelvic inflammatory disease, cervicitis or acute genitourinary infection.
  2. Other genital tract infections including vulvovaginal candidiasis, trichomoniasis, aerobic vaginitis, gonorrhea, genital herpes, condyloma acuminata.
  3. Unexplained vaginal bleeding; uterine leiomyoma, endometrial hyperplasia or adenomyosis interfering with study assessment.
  4. Systemic/vaginal antibacterial or microecological agents within 2 weeks prior to randomization or planned use; vaginal douching / local vaginal therapy within 1 week.
  5. Other vaginal infection diagnosed within 2 weeks before randomization except current index BV episode.
  6. Long-acting injectable contraceptives / sustained-release contraceptives without required wash-out.
  7. Planned systemic steroid therapy within 2 weeks prior to randomization.
  8. Use of disulfiram; systemic alcohol- or propylene-glycol-containing products within 3 days before randomization or planned use, with known interaction with metronidazole.
  9. Major gynecologic surgery within 6 months; superficial gynecologic procedures within 60 days; pregnancy termination less than 60 days.
  10. History of complicated / recurrent vulvovaginal candidiasis within 1 year before ICF.
  11. Malignancy within past 5 years (except basal-/squamous-cell skin carcinoma, papillary thyroid carcinoma, cervical carcinoma in-situ).
  12. Obvious vaginal mucosal injury on gynecological examination.
  13. Intrauterine device in-situ at screening.
  14. Abnormal cervical cytology or positive HPV-16 / HPV-18.
  15. Abnormal lab parameters: Neutrophil\<1.5×10⁹/L; Hb ≤90g/L; platelet\<75×10⁹/L; liver-renal function over 1.5-2×ULN; positive HIV or syphilis test.
  16. Known hypersensitivity to metronidazole, WST03 investigational product or similar vaginal lactobacillus preparations.
  17. History of alcohol or drug abuse.
  18. Psychiatric disorder making subject unable to comply with study.
  19. Pregnant or lactating female.
  20. Participation in another clinical trial within 4 weeks before randomization.
  21. Previous participation in any WST03-related clinical trial.
  22. Any other condition judged by investigator making subject unsuitable for enrollment.
05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Investigator)
Enrollment
150 participants (estimated)

Study arms

  • Experimental
    High-dose WST03 Group

    Participants will receive high-dose WST03 vaginal capsule and oral metronidazole.

    Drug: High-dose WST03 Vaginal Capsule Metronidazole

  • Experimental
    Low-dose WST03 Group

    Participants will receive low-dose WST03 vaginal capsule and oral metronidazole.

    Drug: Low-dose WST03 Vaginal Capsule Metronidazole

  • Placebo comparator
    Placebo Control Group

    Participants will receive visually matched placebo vaginal capsule and oral metronidazole.

    Drug: Placebo Vaginal Capsule Metronidazole

Interventions

  • DrugHigh-dose WST03 Vaginal Capsule Metronidazole

    High-dose vaginal capsule containing multi-strain live lactobacilli; vaginal administration, once daily for 14 consecutive days (Day 1-14). Metronidazole 0.4 g twice daily for 7 days (Day1-7).

  • DrugLow-dose WST03 Vaginal Capsule Metronidazole

    Low-dose vaginal capsule containing multi-strain live lactobacilli; vaginal administration, once daily for 14 consecutive days (Day 1-14). Metronidazole 0.4 g twice daily for 7 days (Day1-7).

  • DrugPlacebo Vaginal Capsule Metronidazole

    Placebo vaginal capsule, visually identical to WST03 capsule, vaginal administration, once daily for 14 consecutive days (Day1-14). Metronidazole 0.4 g twice daily for 7 days (Day1-7).

06

What researchers measure

Primary outcomes

  1. Cumulative recurrence rate of bacterial vaginosis (BV) up to Week-12 visit

    Percentage of participants with BV recurrence through Week 12 among those who achieve composite cure at or before Week 4.

    Time frame: From first study drug administration up to Week-12 visit

Secondary outcomes

  1. BV clinical cure rate at Day-8, Day-15, Week-4 visits

    Percentages of participants achieving protocol-defined clinical cure at each visit.

    Time frame: Day8, Day15, Week4

  2. BV bacteriological cure rate at Day-8, Day-15, Week-4 visits

    Percentages of participants achieving protocol-defined bacteriological cure at each visit.

    Time frame: Day8, Day15, Week4

  3. BV composite cure rate at Day-8, Day-15, Week-4 visits

    Percentages of participants achieving protocol-defined composite cure at each visit.

    Time frame: Day8, Day15, Week4

  4. Cumulative BV recurrence rate up to Week-4 and Week-8 visits

    Percentage of participants with BV recurrence through Weeks 4 and 8 among those who achieve composite cure at or before Week 4.

    Time frame: Up to Week-4, Week-8

  5. Time to first BV recurrence

    Time from composite cure to first BV recurrence among participants who achieve composite cure at or before Week 4.

    Time frame: From composite cure up to Week-12

  6. adverse events during treatment and follow-up period

    Adverse events summarized by participant counts and severity (mild, moderate, or severe)

    Time frame: up to 12 weeks

  7. laboratory abnormalities during treatment and follow-up period

    abnormal laboratory test results will be listed.

    Time frame: up to 12 weeks

07

Study locations

14 sites
  • Beijing Tsinghua Changgung Hospital
    Beijing, Beijing Municipality, China
  • Peking University First Hospital
    Beijing, Beijing Municipality, China
    • Bingbing Xiao · Contact
  • The Second Affiliated Hospital of Chongqing Medical University
    Chongqing, Chongqing Municipality, China
    • Xiaojing Dong · Contact
  • Shenzhen University of Technology General Hospital
    Shenzhen, Guangdong, China
    • Patiman Mijiti · Contact
  • Liuzhou Maternal and Child Health Hospital
    Liuzhou, Guangxi, China
  • The First Affiliated Hospital of Henan Medical University
    Xinxiang, Henan, China
    • Jun Yang · Contact
  • Taihe Hospital, Shiyan City
    Shiyan, Hubei, China
    • Caiyun Fang · Contact
  • Zhuzhou Maternal and Child Health Hospital
    Zhuzhou, Hunan, China
    • Jiqing Wang · Contact
  • The Second Hospital of Jilin University
    Changchun, Jilin, China
    • Tianmin Xu · Contact
  • The First Affiliated Hospital of Xi'an Jiaotong University
    Xi'an, Shaanxi, China
    • Ruifang An · Contact
  • Shanghai First Maternity and Infant Hospital
    Shanghai, Shanghai Municipality, China
    • Xiaowen Pu · Contact
  • The Second Hospital of Shanxi Medical University
    Taiyuan, Shanxi, China
    • Min Hao · Contact
  • Chengdu Women's and Children's Central Hospital
    Chengdu, Sichuan, China
    • Qianling Dai · Contact
  • Women's Hospital, Zhejiang University School of Medicine
    Hangzhou, Zhejiang, China
    • Xiufeng Huang · Contact
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

1 registry update since Sep 25, 2026
Registered
First appeared on the registry. No changes since
Oct 22, 2026
Show all 1 update
  1. Oct 22, 2026
    First appeared on the registry

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT07888699
Lead sponsor
SPH Sine Pharmaceutical Laboratories Co., Ltd.
Responsible party
Sponsor
First posted
Oct 22, 2026
Start date
Oct 20, 2026 (estimated)
Primary completion
Oct 15, 2027 (estimated)
Completion
Dec 25, 2027 (estimated)
Last update
Oct 22, 2026

Study contacts

Qinping Liao
Contact
13701124527@163.com
+8613701124527

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.

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