Study Evaluating ABCL635 for Vasomotor Symptoms of Menopause

June 11, 2026 updated by: AbCellera Biologics Inc.

A First-in-Human Phase 1/2 Study of ABCL635 in Healthy Participants and in Postmenopausal Women With Moderate-to-Severe Vasomotor Symptoms

The purpose of this study is to evaluate the effects of single and multiple doses of ABCL635 administered by subcutaneous (SC) injection to healthy men and to postmenopausal women with or without any vasomotor symptoms (VMS) or hot flashes, and to postmenopausal women with moderate-to-severe VMS associated with menopause. The safety, tolerability, pharmacokinetic (PK) and pharmacodynamic (PD) parameters of ABCL635 will be assessed in all study participants; the effects on frequency and severity of VMS will be assessed in postmenopausal women who experience moderate-to-severe symptoms.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The study consists of 3 parts: Part A and Part B (Phase 1) and Part C (Phase 2). In Part A, single ascending doses (SAD) of ABCL635 or placebo will be administered to healthy male and female participants. In Part B, up to 3 multiple ascending doses (MAD) of ABCL635 or placebo will be administered to healthy postmenopausal women with or without VMS. In Part C, a single dose of ABCL635 or placebo will be administered to postmenopausal women experiencing moderate-to-severe VMS associated with menopause. In Part C, all participants will be offered to participate in an open label extension (OLE) cohort and receive a single dose of ABCL635 upon completion of a 12-week assessment.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
136

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Canada
    • Alberta
      • Calgary, Alberta, Canada, T2N 4L7
        • CaRe Clinics
      • Red Deer, Alberta, Canada, T4P 1K4
        • CaRe Clinics
    • British Columbia
      • Vancouver, British Columbia, Canada, V5T 3N4
        • Mount Saint Joseph Hospital Clinical Trials Phase 1 Unit
    • Ontario
      • Toronto, Ontario, Canada, M4G 3E8
        • Centricity Research
      • Toronto, Ontario, Canada, M4W 4L6
        • Centricity Research
    • Quebec
      • Lévis, Quebec, Canada, G6V 0C9
        • Alpha Recherche Clinique
      • Montreal, Quebec, Canada, H1Y 3H5
        • GCP Research
      • Mount Royal, Quebec, Canada, H3P 3P1
        • Altasciences Company Inc.
      • Québec, Quebec, Canada, G1V 4T3
        • Diex Recherche Québec
      • Québec, Quebec, Canada, G1V 3M8
        • Clinique RSF Inc.
      • Sherbrooke, Quebec, Canada, J1L 0H8
        • Diex Recherche Sherbrooke
      • Trois-Rivières, Quebec, Canada, GSA 4P3
        • Diex Recherche Trois-rivieres
      • Victoriaville, Quebec, Canada, G6P 3Z8
        • Diex Recherche Victoriaville

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Good general health as determined through a review of their medical history and after conducting a general physical examination
  • Body weight ≥ 45 to ≤ 120 kg
  • Body mass index (BMI) between 18.5 kg/m2 and 35.0 kg/m2
  • Non- or ex-smoker (an ex-smoker is defined as someone who completely stopped using nicotine products for at least 90 days prior to the first study drug administration)
  • Healthy man or a postmenopausal woman who is ≥ 40 and ≤ 75 years of age OR a postmenopausal woman with or without VMS and who is ≥ 40 and ≤ 75 years of age OR a postmenopausal woman who is ≥ 40 and ≤ 75 years of age seeking treatment for relief for VMS

  • If a woman:

    1. has been compliant with local and/or national guidelines for breast cancer screening with documentation of a mammogram with normal/negative or no clinically significant findings. A screening mammogram may be conducted during study screening period, if needed
    2. has spontaneous amenorrhea for at least 12 consecutive months; or spontaneous amenorrhea for at least 6 months with biochemical criteria of menopause (follicle-stimulating hormone [FSH] > 40 IU/L); or had a bilateral oophorectomy > 6 weeks prior to screening, or s/p hysterectomy at least 6 weeks prior to screening and meeting the biochemical criteria of menopause (FSH > 40 IU/L)

  • If a man:

    1. possess a testosterone concentration of ≥ 15 nmol/L at the time of screening
    2. can procreate and agree to use one of the acceptable contraceptive regimens and not to donate sperm from the first study drug administration to at least 90 days after the last drug administration OR is unable to procreate; defined as surgically sterile

Exclusion Criteria:

  • Pregnancy and/or lactation.
  • Has endometrial hyperplasia or history of abnormal uterine bleeding without an identified cause in the past 6 months
  • Previous or current history of a malignant tumor, except for non-melanoma skin cancer.
  • Seated pulse rate less than 50 beats per minute (bpm) or more than 100 bpm or a seated blood pressure < 90/50 mmHg or > 140/90 mmHg
  • eGFR < 60 mL/min/1.73 m2
  • Severe hypersensitivity reactions (like angioedema) to any drugs.
  • Significant uncontrolled cardiovascular, pulmonary, gastrointestinal, hepatic, renal, hematologic, neurological, psychiatric, endocrine, immunologic, or dermatologic disease.
  • Clinically significant ECG abnormalities
  • Presence or history of cardiogenic syncope in the past 6 months.
  • Use of any over-the-counter products (including supplements) containing testosterone or any medication (hormonal, prescription, over the counter, herbal, or natural) for the treatment of hot flashes during the screening period and throughout the study; must be discontinued at least 28 days prior to study drug administration
  • Employees of the sponsor or the investigator site and other individuals who are directly involved in the conduct of the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: ABCL635 Part A
Part A: healthy male and female participants will receive a single dose of ABCL635 administered by subcutaneous (SC) injection
Biological: ABCL635
Participants will receive SC administrations of ABCL635
Placebo Comparator: Placebo Part A
Part A: Healthy male and female participants will receive a single dose of placebo (dextrose 5% solution) administered by SC injection
Biological: Placebo
Participants will receive SC administration of placebo (5% dextrose solution)
Experimental: ABCL635 Part B
Part B: healthy postmenopausal women with or without VMS will receive up to 3 doses of ABCL635 administered by SC injection
Biological: ABCL635
Participants will receive SC administrations of ABCL635
Placebo Comparator: Placebo Part B
Part B: healthy postmenopausal women with or without VMS will receive up to 3 doses of placebo (dextrose 5% solution) administered by SC injection
Biological: Placebo
Participants will receive SC administration of placebo (5% dextrose solution)
Experimental: ABCL635 Part C
Part C: postmenopausal women with moderate to severe VMS will receive a single dose of ABCL635 administered by SC injection
Biological: ABCL635
Participants will receive SC administrations of ABCL635
Placebo Comparator: Placebo Part C
Part C: postmenopausal women with moderate to severe VMS will receive a single dose of placebo (dextrose 5% solution) administered by SC injection
Biological: Placebo
Participants will receive SC administration of placebo (5% dextrose solution)
Experimental: ABCL635 Part C OLE
Part C open label extension (OLE): postmenopausal women with moderate to severe VMS will receive a single dose of ABCL635 administered by SC injection upon completion of 12-week assessment.
Biological: ABCL635
Participants will receive SC administrations of ABCL635

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Frequency and severity of adverse events (AE)
Time Frame: Day 0 to day 197
Day 0 to day 197
Number of participants with abnormalities in 12-lead safety electrocardiograms (ECG)
Time Frame: Day 0 to day 197
Day 0 to day 197
Number of participants with abnormalities in physical examination
Time Frame: Day 0 to day 197
Day 0 to day 197
Number of participants with abnormalities in laboratory parameters, including general biochemistry, hematology, endocrinology, and urinalysis
Time Frame: Day 0 to day 197
Day 0 to day 197

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Plasma concentrations of ABCL635
Time Frame: Day 0 to day 197
Day 0 to day 197
Incidence of anti-ABCL635 antibodies
Time Frame: Day 0 to day 197
Day 0 to day 197
PK parameters; maximum plasma concentration (Cmax)
Time Frame: Day 0 to day 197
Day 0 to day 197
PK parameters; time to maximum plasma concentration (Tmax)
Time Frame: Day 0 to day 197
Day 0 to day 197
PK parameters; area under the plasma concentration-time curve from zero to the time of the last quantifiable concentration (AUC0-T)
Time Frame: Day 0 to day 197
Day 0 to day 197
PK parameters; area under the plasma concentration-time curve from zero to hour 672 (AUC0-672)
Time Frame: Day 0 to day 197
Day 0 to day 197
PK parameters; area under the plasma concentration-time curve from zero to infinity (AUC0-∞)
Time Frame: Day 0 to day 197
Day 0 to day 197
PK parameters; percent of AUC obtained by extrapolation (%AUCextrap)
Time Frame: Day 0 to day 197
Day 0 to day 197
PK parameters; terminal rate constant (λz)
Time Frame: Day 0 to day 197
Day 0 to day 197
PK parameters; apparent plasma clearance of drug after extravascular administration (CL/F)
Time Frame: Day 0 to day 197
Day 0 to day 197
PK parameters; apparent volume of distribution after extravascular administration (Vz/F)
Time Frame: Day 0 to day 197
Day 0 to day 197
PK parameters; half-life (Thalf)
Time Frame: Day 0 to day 197
Day 0 to day 197
Mean change from baseline to each study week in the frequency of moderate and severe VMS (VMSM-S frequency)
Time Frame: up to day 141 (Part C)
up to day 141 (Part C)
Mean change from baseline to each study week in the severity of moderate and severe VMS (VMSM-S severity)
Time Frame: up to day 141 (Part C)
up to day 141 (Part C)
Mean change from baseline to each study week in the frequency of all reported VMS (VMSTotal frequency).
Time Frame: up to day 141 (Part C)
up to day 141 (Part C)
Mean change from baseline to each study week in the moderate to severe hot flash score (HFM-S).
Time Frame: up to day 141 (Part C)

The moderate to severe hot flash score (HFM-S) is a metric that combines the frequency and severity of hot flashes:

  • The daily score is calculated as follows: (number of moderate hot flashes x 2) + (number of severe hot flashes x 3)
  • The weekly score is the average daily score over seven days. A negative change in the score from Baseline to Week 1 indicates a reduction in the severity and frequency of hot flashes
up to day 141 (Part C)
Mean change in the Menopause-Specific Quality of Life Questionnaire (MENQOL) 4-domain scores (ie, physical, vasomotor, psychosocial, and sexual) from baseline to weeks 1, 2, 3, 4, 5, 9, and 13
Time Frame: up to day 141 (Part C)

The Mean change in the Menopause-Specific Quality of Life Questionnaire (MENQOL) measures the impact of menopause symptoms over the last week.

The questionnaire has 29 items across four domains: vasomotor (items 1 to 3), psychosocial (items 4 to 10), physical (items 11 to 26), and sexual (items 27 to 29). Items pertaining to a specific symptom are rated as present or not present, and if present, how bothersome on a 0 (not bothersome) to 6 (extremely bothersome) scale.

The mean change in the MENQOL domain scores will be assessed from Baseline to each week measured. A negative change in the score from Baseline to each week measured indicates an improvement in quality of life.
up to day 141 (Part C)
Mean change in the Patient-Reported Outcomes Measurement Information System Sleep Disturbance 8b Short Form (PROMIS-SD-SF-8b) total score from baseline to weeks 1, 2, 3, 4, 5, 9, and 13.
Time Frame: up to day 141 (Part C)

The PROMIS-SD-SF-8b assesses the perception of sleep quality, sleep depth, and any perceived difficulties related to getting and staying asleep. Questions are scored using the following scale: 1 (very much), 2 (quite a bit), 3 (somewhat), 4 (a little bit), and 5 (not at all).

The mean change in the PROMIS-SD-SF-8b score will be assessed from Baseline to each week measured. A positive change in the score from Baseline to each week measured indicates a reduction in sleep disturbance.
up to day 141 (Part C)
Frequency of Patient Global Impression of Change in VMS (PGI-C VMS) responses at weeks 2, 3, 4, 5, 9, and 13.
Time Frame: up to day 141 (Part C)
The Patient Global Impression of Change (PGI-C) for vasomotor symptoms (VMS) rates the perception of their hot flashes and night sweats at each designated timepoint compared to the start of the study. The response is a seven-point scale ranging from "much better" to "much worse." The frequency of each PGI-C VMS score will be reported at each scheduled timepoint.
up to day 141 (Part C)
Mean change from baseline to each study week in the total hot flash score (HFTotal).
Time Frame: up to day 141 (Part C)

The total hot flash score (HFTotal) is a metric that combines the frequency and severity of hot flashes:

  • The daily score is calculated as follows: (number of mild hot flashes x 1) + (number of moderate hot flashes x 2) + (number of severe hot flashes x 3)
  • The weekly score is the average daily score over seven days. A negative change in the score from Baseline to Week 1 indicates a reduction in the severity and frequency of hot flashes.
up to day 141 (Part C)

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Time Frame
Physiological PD parameters; change over time from baseline in LH and FSH (men and women), testosterone in men only, and estradiol in women only
Time Frame: Day 0 to day 197
Day 0 to day 197
PK-PD; Relationship between selected PK endpoints and relevant physiological and behavioral PD endpoints
Time Frame: Day 0 to day 197
Day 0 to day 197

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
AbCellera Biologics Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Eric Sicard, Altasciences Company Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 23, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 16, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 5, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 12, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 11, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ABCL635-101
  • 297103 (Other Identifier: Health Canada CTA control number)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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