HR+ HER2- Breast CancerPhase 1/2NCT07558733
Sapanisertib and Serabelisib (PIKTOR) in Various Combinations in Patients With HR+/HER2- Advanced/Metastatic Breast Cancer
A Phase 1/2 study testing Serabelisib, Sapanisertib and Fulvestrant in people with HR+ HER2- Breast Cancer, run by Faeth Therapeutics at 7 sites in United States.
Trial summary
The study is a Phase 1b/2, multi-center, open-label, dose escalation trial evaluating the safety and preliminary efficacy of sapanisertib and serabelisib (PIKTOR) with fulvestrant and/or other anticancer therapies in participants with HR+/HER2- advanced/metastatic breast cancer. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- HR+ HER2- Breast Cancer
- What is being tested?
- Serabelisib, Sapanisertib and Fulvestrant
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 7 sitesUnited States
- Study dates
- 22 Apr 2026to May 2033
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Histologically confirmed diagnosis of HR+/HER2- breast cancer.
- Documented evidence of advanced or recurrent disease that is not amenable to surgery/radiation for curative intent.
- Participant has received at least one prior systemic therapy.
- At least 1 measurable or evaluable target lesion according to RECIST v1.1
- Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 1 at Screening.
- Non-pregnant, non-lactating females who are postmenopausal, surgically sterile or who agree to use effective contraceptive methods.
Who cannot join
- Participants with triple-negative breast cancer.
- Participants with central nervous system metastases are not eligible, unless they have completed local therapy and have discontinued the use of corticosteroids for this indication for at least 4 weeks before starting treatment in this study.
- Active malignancy (except for breast cancer, definitively treated in-situ carcinomas [e.g., breast, cervix, bladder], or basal or squamous cell carcinoma of the skin) within the past 24 months prior to treatment. Fully resected localized malignancies are eligible.
- Gastric feeding tube (gastrostomy tube), gastrointestinal malabsorption, gastrointestinal anastomosis, bowel obstruction, or any other condition that might affect the absorption of study treatment.
- Significant cardiovascular impairment.
- Active, uncontrolled infection.
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- Concurrent participation in another therapeutic clinical trial.
- Prior radiation therapy within 21 days prior to start of study treatment.
- Participants who have received a prior PI3K, AKT, mTORC1/2, or dual PI3K/mTOR inhibitor.
- Strong CYP3A4 inhibitors, strong CYP1A2 inhibitors or CYP1A2 inducers, or clinically significant CYP3A4 inducers within 7 days before the first dose of study intervention, or participants who require treatment with strong CYP3A4 inhibitors or inducers during the study.
- Prolongation of QTc interval to >480 ms.
- Type 1 or Type 2 diabetes mellitus on insulin.
Trial locations and contacts
7 sites in 1 country. Contact the study team or a site near you to ask about taking part.
7 sites in 1 country
United States7 sites, 7 recruiting
- Recruiting
Texas Oncology - Central/South
Austin, Texas, 78731
- Recruiting
Rocky Mountain Cancer Centers
Lone Tree, Colorado, 80124
- Recruiting
START Los Angeles
Los Angeles, California, 90025
- Recruiting
SCRI Oncology Partners
Nashville, Tennessee, 37203
- Recruiting
START San Antonio
San Antonio, Texas, 78229
- Recruiting
Texas Oncology - San Aantonio
San Antonio, Texas, 78240
- Recruiting
Oncology Associates of Oregon
Springfield, Oregon, 97477
About this study
Official title: Open-Label Umbrella Study to Evaluate Safety and Efficacy of Sapanisertib and Serabelisib (PIKTOR) in Various Combinations in Patients With HR+/HER2- Advanced or Metastatic Breast Cancer
The study is a Phase 1b/2, multi-center, open-label, dose escalation trial evaluating the safety and preliminary efficacy of sapanisertib and serabelisib (PIKTOR) with fulvestrant and/or other anticancer therapies in participants with HR+/HER2- advanced/metastatic breast cancer.
Read the detailed description
The study is a Phase 1b/2, multi-center, open-label, dose escalation trial evaluating the safety and preliminary efficacy of sapanisertib and serabelisib (PIKTOR) with fulvestrant and/or other anticancer therapies in participants with HR+/HER2- advanced/metastatic breast cancer.
- Conditions
- HR+ HER2- Breast Cancer
- Being tested
- Serabelisib, Sapanisertib, Fulvestrant
- Keywords
- Serabelisib, Sapanisertib, Fulvestrant, Palbociclib, PI3K, mTOR, Dual PI3K/mTOR inhibition, Genetic Mutation, Faslodex, SERDs, Select Estrogen Receptor Degraders, CDK, CDK46, CDK4-6, HER2-, HER2 negative, HR+, HR positive, Hormone Receptor Positive, Advanced Breast Cancer
- Medical subject headings
- Breast Neoplasms, Hereditary Sensory and Autonomic Neuropathies
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SerabelisibDrug
Serabelisib is a selective, small molecule inhibitor of PI3Kα.
SapanisertibDrug
Sapanisertib is a small molecule inhibitor of the mammalian mTOR serine/threonine kinase.
FulvestrantDrug
Fulvestrant is a first-in-class SERD.
| Study group | Role | What they receive |
|---|---|---|
| Cohort A1 - Sapanisertib and serabelisib (PIKTOR) with fulvestrant | Experimental | Subjects will receive doses of sapanisertib and serabelisib (PIKTOR) administered orally and fulvestrant administered intramuscularly. Receives: Drug: Serabelisib; Drug: Sapanisertib; Drug: Fulvestrant |
| Cohort A2 - Sapanisertib and serabelisib (PIKTOR) with fulvestrant | Experimental | Subjects will receive doses of sapanisertib and serabelisib (PIKTOR) at a higher dose than Cohort A1 administered orally and fulvestrant administered intramuscularly. Receives: Drug: Serabelisib; Drug: Sapanisertib; Drug: Fulvestrant |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety and tolerability of drugs by assessment of adverse events (AEs) / serious adverse events (SAEs)
Graded according to the National Cancer Institute (NCI CTCAE v5.0).
Measured: 2 years
Secondary outcomes (6)
Objective Response Rate (ORR)
Defined as the proportion of participants from the Response-Evaluable population who have confirmed best overall response of either CR or PR according to RECIST v1.1 as confirmed by the Investigator.
Measured: Up to 2 years.
Progression Free Survival (PFS)
Defined as the time from first dose to the date of the first evidence of disease progression or death.
Measured: Up to 5 years.
Progression Free Survival (PFS) at 6 months
Defined as the progression free survival (PFS) rate at 6 months.
Measured: 6 months
Overall Survival (OS)
Defined as the time from first dose to the date of death due to any cause.
Measured: Up to 5 years.
Clinical Benefit Rate (CBR)
Defined as the percentage of participants from the All Treated population who achieve CR, PR, or SD.
Measured: Up to 5 years.
Duration of Response (DoR)
Defined for participants with a confirmed CR or PR as the time from response to the date of first evidence of disease progression or death.
Measured: Up to 5 years.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Apr 2026
- Study start22 Apr 2026
- Primary completionMay 2029 (estimated)
- Study completionMay 2033 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HR+ HER2- Breast CancerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 32 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Faeth Therapeutics
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07558733
- Sponsor's protocol ID
- FTH-PIK-101
- Status last verified
- Apr 2026
- First submitted
- 17 Apr 2026
- Last updated
- 2 Jul 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Open-Label Umbrella Study to Evaluate Safety and Efficacy of Sapanisertib and Serabelisib (PIKTOR) in Various Combinations in Patients With HR+/HER2- Advanced or Metastatic Breast Cancer
- ClinicalTrials.gov ID
- NCT07558733
- Acronym / sponsor ID
- FTH-PIK-101
- Conditions
- HR+ HER2- Breast Cancer
- Keywords
- Serabelisib, Sapanisertib, Fulvestrant, Palbociclib, PI3K, mTOR, Dual PI3K/mTOR inhibition, Genetic Mutation
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 32 participants (estimated)
- Lead sponsor
- Faeth TherapeuticsIndustry (pharma, biotech, devices)
- Study start
- 22 Apr 2026 (actual)
- Primary completion
- May 2029 (estimated)
- Study completion
- May 2033 (estimated)
- First posted
- 30 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The study is a Phase 1b/2, multi-center, open-label, dose escalation trial evaluating the safety and preliminary efficacy of sapanisertib and serabelisib (PIKTOR) with fulvestrant and/or other anticancer therapies in participants with HR+/HER2- advanced/metastatic breast cancer.
Detailed description
The study is a Phase 1b/2, multi-center, open-label, dose escalation trial evaluating the safety and preliminary efficacy of sapanisertib and serabelisib (PIKTOR) with fulvestrant and/or other anticancer therapies in participants with HR+/HER2- advanced/metastatic breast cancer.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Cohort A1 - Sapanisertib and serabelisib (PIKTOR) with fulvestrant | Experimental | Drug: Serabelisib, Drug: Sapanisertib, Drug: FulvestrantSubjects will receive doses of sapanisertib and serabelisib (PIKTOR) administered orally and fulvestrant administered intramuscularly. |
| Cohort A2 - Sapanisertib and serabelisib (PIKTOR) with fulvestrant | Experimental | Drug: Serabelisib, Drug: Sapanisertib, Drug: FulvestrantSubjects will receive doses of sapanisertib and serabelisib (PIKTOR) at a higher dose than Cohort A1 administered orally and fulvestrant administered intramuscularly. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Histologically confirmed diagnosis of HR+/HER2- breast cancer.
- Documented evidence of advanced or recurrent disease that is not amenable to surgery/radiation for curative intent.
- Participant has received at least one prior systemic therapy.
- At least 1 measurable or evaluable target lesion according to RECIST v1.1
- Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 1 at Screening.
Key exclusion criteria (12 listed)
- Participants with triple-negative breast cancer.
- Participants with central nervous system metastases are not eligible, unless they have completed local therapy and have discontinued the use of corticosteroids for this indication for at least 4 weeks before starting treatment in this study.
- Active malignancy (except for breast cancer, definitively treated in-situ carcinomas [e.g., breast, cervix, bladder], or basal or squamous cell carcinoma of the skin) within the past 24 months prior to treatment. Fully resected localized malignancies are eligible.
- Gastric feeding tube (gastrostomy tube), gastrointestinal malabsorption, gastrointestinal anastomosis, bowel obstruction, or any other condition that might affect the absorption of study treatment.
- Significant cardiovascular impairment.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SerabelisibSerabelisib is a selective, small molecule inhibitor of PI3Kα. | Drug | Cohort A1 - Sapanisertib and serabelisib (PIKTOR) with fulvestrant, Cohort A2 - Sapanisertib and serabelisib (PIKTOR) with fulvestrant |
| SapanisertibSapanisertib is a small molecule inhibitor of the mammalian mTOR serine/threonine kinase. | Drug | Cohort A1 - Sapanisertib and serabelisib (PIKTOR) with fulvestrant, Cohort A2 - Sapanisertib and serabelisib (PIKTOR) with fulvestrant |
| FulvestrantFulvestrant is a first-in-class SERD. | Drug | Cohort A1 - Sapanisertib and serabelisib (PIKTOR) with fulvestrant, Cohort A2 - Sapanisertib and serabelisib (PIKTOR) with fulvestrant |
Primary outcome
Safety and tolerability of drugs by assessment of adverse events (AEs) / serious adverse events (SAEs)
Time frame: 2 years
Graded according to the National Cancer Institute (NCI CTCAE v5.0).
6 secondary outcomes
Objective Response Rate (ORR)
Time frame: Up to 2 years.
Progression Free Survival (PFS)
Time frame: Up to 5 years.
Progression Free Survival (PFS) at 6 months
Time frame: 6 months
Overall Survival (OS)
Time frame: Up to 5 years.
Clinical Benefit Rate (CBR)
Time frame: Up to 5 years.
Duration of Response (DoR)
Time frame: Up to 5 years.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Jul 2026.
- Related InfoLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
7 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Serabelisib, Sapanisertib and Fulvestrant in people with HR+ HER2- Breast Cancer, run by Faeth Therapeutics at 7 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Medical Monitor ((708) 406-9282, clinicaltrials@faeththerapeutics.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety and tolerability of drugs by assessment of adverse events (AEs) / serious adverse events (SAEs) (time frame: 2 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jul 2026.