A Study of ABI-2280 Vaginal Insert (Previously Referred to as ABI-2280 Vaginal Tablet) in Participants With Cervical Intraepithelial Neoplasia

Inclusion Criteria:

• Women, 25 to 55 years old.

• For Cohorts A1 and A2 in Part A, participants with biopsy-confirmed CIN (withvisible lesions) regardless of p16 positivity may be enrolled upon consultation withPI and Medical Monitor. These participants will not be required to get LLETZ if notmedically necessary, as determined by the PI in consultation with the MedicalMonitor.

• For Cohorts A3 and above in Part A and Part B POC cohorts, biopsy-confirmed cHSILthat is p16+ (p16INK4a expressed) within 60 days of enrollment (dosing) with noevidence of invasive cancer in any specimen. If biopsy was performed ≥ 60 daysbefore planned enrollment, participants must agree to have another biopsy performedat the Screening visit, unless approved by the Medical Monitor.

• A positive high-risk HPV (hrHPV) result by provider-obtained cervical swab atscreening or previously obtained and documented within the past 3 months.

• No prior treatment for Cervical intraepithelial neoplasia (CIN).

• Generally, in good health with no clinically significant pulmonary, cardiac,gastro-enterologic, neurologic, renal, musculoskeletal, rheumatologic, metabolic,neoplastic, or endocrine disease.

Exclusion Criteria:

• Women who are pregnant, plan to become pregnant in the next 4 months, or lactatingfemales.

• Unwilling to use stringent methods of contraception (including barrier method, aswell as another acceptable method) throughout the course of the study.

• History of cancer, except basal cell or squamous cell carcinoma of the skin.

• History of genital herpes with outbreak within prior 12 months.

• Have an active pelvic or non-HPV (Human papillomavirus) vaginal infection (e.g.,that was detected by a positive urine screen for gonorrhea or chlamydial infection,bimanual exam consistent with pelvic inflammatory disease, positive bedside testingcriteria for bacterial vaginosis, candida vaginitis or trichomonal vaginitis, etc).

• Current or recent abnormal vaginal discharge and /or abnormal vaginal bleeding.

• Had a therapeutic abortion or miscarriage less than 3 months prior.

• Any clinically significant immune suppressing condition.

• Participants with a significant acute condition or any other condition that in theopinion of the Investigator might interfere with the evaluation of the studyobjectives.

• Women who, in the PI's judgment, would be harmed by the delay in undergoingdefinitive treatment as a result of study participation and the ABI-2280 VaginalTablet dosing schedule.

• Vaccination (even 1 dose) with a prophylactic HPV vaccine (i.e., Gardasil®,Gardasil®-9 or Cervarix®) in the last 3 months.

• Vaccination with a therapeutic HPV vaccine.

• Other inclusion/exclusion criteria may apply