Cancer-NeoplasmsPhase 1STARLYSNCT07610941
Phase 1 Open Label Trial of MST-0312 Alone and in Combination in Subjects With Solid Malignancies
A Phase 1 study testing MST-0312 and Pembrolizumab in people with Cancer-Neoplasms, run by Mestag Therapeutics Limited at 6 sites in Spain.
Trial summary
The STARLYS trial is an adaptive, modular, Phase 1, open-label, multi-part, clinical trial evaluating MST-0312 in selected solid tumors. MST-0312 is a targeted bispecific antibody that is designed to locally stimulate the lymphotoxin beta receptor (LTBR) in order to boost the body's immune response to cancer. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cancer-Neoplasms
- What is being tested?
- MST-0312 and Pembrolizumab
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 157 participants
- Where
- 6 sitesSpain
- Study dates
- 9 Apr 2026to 31 Dec 2029
- Phase
- Phase 1
- 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
- Male and female subjects of any ethnic origin, aged 18 years and over.
- Must have given written informed consent and must be able to understand the full nature and purpose of the trial, including possible risks and adverse effects.
- Subject must have a solid malignancy (non-small cell lung cancer (NSCLC), melanoma, bladder cancer, colorectal cancer (CRC) and triple negative breast cancer (TNBC)).
- An ECOG performance status of 0 or 1 with no deterioration over the previous two weeks.
- Willing to permit access to stored historical tumour tissue and prior tumour radiological assessments, cancer treatment history, including response to treatment, and tumour biomarker data, where available.
- Willing and able to comply with all scheduled visits, treatment plans, laboratory tests, and other trial procedures.
Who cannot join
- Any unresolved toxicity (except alopecia) from prior therapy of ≥2 CTCAE Grade.
- Active or documented history of autoimmune disease requiring interventional therapy.
- Active infection requiring systemic antibiotic, antifungal, or antiviral medication within 14 days prior to first dose of IMP.
- Male or female subjects of childbearing potential unwilling to comply with contraception requirements.
Trial locations and contacts
6 sites in 1 country. Contact the study team or a site near you to ask about taking part.
6 sites in 1 country
Spain6 sites, 6 recruiting
- Not yet recruiting
Hospital Universitari Vall d'Hebron
Barcelona, 08035
- Not yet recruiting
Clinica Universidad De Navarra
Madrid, 28027
- Recruiting
Hospital Universitario Fundacion Jimenez Diaz
Madrid, 28040
- Not yet recruiting
Hospital Universitario 12 De Octubre
Madrid, 28041
- Recruiting
Hospital Universitario Hm Sanchinarro
Madrid, 28050
- Not yet recruiting
Hospital Clinico Universitario De Valencia
Valencia, 46010
About this study
Official title: A Multi-arm, Open-label, Phase 1 Trial to Evaluate the Safety and Tolerability, Pharmacokinetics and Anti-tumour Activity of MST-0312 When Given Alone and in Combination With Anticancer Treatments in Subjects With Solid Malignancies
The STARLYS trial is an adaptive, modular, Phase 1, open-label, multi-part, clinical trial evaluating MST-0312 in selected solid tumors. MST-0312 is a targeted bispecific antibody that is designed to locally stimulate the lymphotoxin beta receptor (LTBR) in order to boost the body's immune response to cancer. The LTBR pathway is important in forming tertiary lymphoid structures and high endothelial venules in tumors, which have been associated with improved patient outcomes. The purpose of this study is to determine the safety and tolerability, pharmacodynamics, pharmacokinetics and anti-tumor activity of MST-0312 in subjects with solid malignancies (initially non-small cell lung cancer (NSCLC), melanoma, bladder cancer, colorectal cancer (CRC) and triple negative breast cancer (TNBC)) when administered either as monotherapy or in combination with anti-cancer treatments (initially pembrolizumab). The STARLYS trial is the first time MST-0312 has been administered to humans.
- Conditions
- Cancer-Neoplasms
- Being tested
- MST-0312, Pembrolizumab
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MST-0312Drug
A complete treatment cycle is defined as 21 calendar days.
PembrolizumabDrug
Also called Keytruda
Monoclonal antibody
| Study group | Role | What they receive |
|---|---|---|
| Module 1A | Experimental | MST-0312 monotherapy dose escalation Receives: Drug: MST-0312 |
| Module 1B | Experimental | MST-0312 monotherapy backfill Receives: Drug: MST-0312 |
| Module 2A | Experimental | MST-0312 plus pembrolizumab dose escalation Receives: Drug: MST-0312; Drug: Pembrolizumab |
| Module 2B | Experimental | MST-0312 plus pembrolizumab backfill Receives: Drug: MST-0312; Drug: Pembrolizumab |
| Module 2C | Experimental | MST-0312 plus pembrolizumab expansion Receives: Drug: MST-0312; Drug: Pembrolizumab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of Dose-limiting Toxicities (DLTs)
Measured: From baseline to end cycle 1. A complete treatment cycle is defined as 21 calendar days.
Incidence of Adverse Events, Treatment Emergent Adverse Events, Serious Adverse Events measured by Criteria for Adverse Events Version 6.0 (CTCAE v6.0)
Measured: Up to 24 months
Secondary outcomes (14)
Maximum Concentration (Cmax) Derived for MST-0312
Measured: 24 months
Time of Maximum Concentration (Tmax)
Measured: 24 Months
Area Under the Curve (AUC) for Various Time Intervals
Measured: 24 Months
Half Life (t1/2) for MST-0312
Measured: 24 Months
Clearance (CL) for MST-0312
Measured: 24 Months
Percentage of Participants with Anti-Drug Antibodies (ADAs)
Measured: 24 Months
Objective Response Rate (ORR) by RECIST 1.1 and iRECIST
Measured: 12 Months
Disease Control Rate (DCR) by RECIST 1.1 and iRECIST
Measured: 12 Months
Duration of Response (DoR) by RECIST 1.1 and iRECIST
Measured: 12 Months
Progression Free Survival (PFS) by RECIST 1.1 and iRECIST
Measured: 12 Months
Best Overall Response (BoR) by RECIST 1.1 and iRECIST
Measured: 12 Months
Time To Response (TTR) by RECIST 1.1 and iRECIST
Measured: 12 Months
Progression Free Survival 2 (PFS2) by RECIST 1.1 and iRECIST
Measured: 48 Months
Overall Survival (OS)
Measured: 48 Months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 May 2026
- Study start9 Apr 2026
- Primary completion31 Dec 2029 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cancer-NeoplasmsStudies 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
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 157 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Mestag Therapeutics Limited
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07610941
- Sponsor's protocol ID
- MST-0312-1001
- Other IDs
- 2025-524446-10, 2025
- Acronym
- STARLYS
- Status last verified
- May 2026
- First submitted
- 14 May 2026
- Last updated
- 1 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Multi-arm, Open-label, Phase 1 Trial to Evaluate the Safety and Tolerability, Pharmacokinetics and Anti-tumour Activity of MST-0312 When Given Alone and in Combination With Anticancer Treatments in Subjects With Solid Malignancies
- ClinicalTrials.gov ID
- NCT07610941
- Acronym / sponsor ID
- STARLYS / MST-0312-1001
- Conditions
- Cancer-Neoplasms
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 157 participants (estimated)
- Lead sponsor
- Mestag Therapeutics LimitedIndustry (pharma, biotech, devices)
- Study start
- 9 Apr 2026 (actual)
- Primary completion
- 31 Dec 2029 (estimated)
- Study completion
- 31 Dec 2029 (estimated)
- First posted
- 28 May 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 STARLYS trial is an adaptive, modular, Phase 1, open-label, multi-part, clinical trial evaluating MST-0312 in selected solid tumors. MST-0312 is a targeted bispecific antibody that is designed to locally stimulate the lymphotoxin beta receptor (LTBR) in order to boost the body's immune response to cancer. The LTBR pathway is important in forming tertiary lymphoid structures and high endothelial venules in tumors, which have been associated with improved patient outcomes. The purpose of this study is to determine the safety and tolerability, pharmacodynamics, pharmacokinetics and anti-tumor activity of MST-0312 in subjects with solid malignancies (initially non-small cell lung cancer (NSCLC), melanoma, bladder cancer, colorectal cancer (CRC) and triple negative breast cancer (TNBC)) when administered either as monotherapy or in combination with anti-cancer treatments (initially pembrolizumab). The STARLYS trial is the first time MST-0312 has been administered to humans.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| Module 1A | Experimental | Drug: MST-0312MST-0312 monotherapy dose escalation |
| Module 1B | Experimental | Drug: MST-0312MST-0312 monotherapy backfill |
| Module 2A | Experimental | Drug: MST-0312, Drug: PembrolizumabMST-0312 plus pembrolizumab dose escalation |
| Module 2B | Experimental | Drug: MST-0312, Drug: PembrolizumabMST-0312 plus pembrolizumab backfill |
| Module 2C | Experimental | Drug: MST-0312, Drug: PembrolizumabMST-0312 plus pembrolizumab expansion |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Male and female subjects of any ethnic origin, aged 18 years and over.
- Must have given written informed consent and must be able to understand the full nature and purpose of the trial, including possible risks and adverse effects.
- Subject must have a solid malignancy (non-small cell lung cancer (NSCLC), melanoma, bladder cancer, colorectal cancer (CRC) and triple negative breast cancer (TNBC)).
- An ECOG performance status of 0 or 1 with no deterioration over the previous two weeks.
- Willing to permit access to stored historical tumour tissue and prior tumour radiological assessments, cancer treatment history, including response to treatment, and tumour biomarker data, where available.
Key exclusion criteria (4 listed)
- Any unresolved toxicity (except alopecia) from prior therapy of ≥2 CTCAE Grade.
- Active or documented history of autoimmune disease requiring interventional therapy.
- Active infection requiring systemic antibiotic, antifungal, or antiviral medication within 14 days prior to first dose of IMP.
- Male or female subjects of childbearing potential unwilling to comply with contraception requirements.
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 |
|---|---|---|
| MST-0312A complete treatment cycle is defined as 21 calendar days. | Drug | Module 1A, Module 1B, Module 2A, Module 2B, Module 2C |
| PembrolizumabAlso: KeytrudaMonoclonal antibody | Drug | Module 2A, Module 2B, Module 2C |
Primary outcome
Incidence of Dose-limiting Toxicities (DLTs)
Time frame: From baseline to end cycle 1. A complete treatment cycle is defined as 21 calendar days.
Incidence of Adverse Events, Treatment Emergent Adverse Events, Serious Adverse Events measured by Criteria for Adverse Events Version 6.0 (CTCAE v6.0)
Time frame: Up to 24 months
14 secondary outcomes
Maximum Concentration (Cmax) Derived for MST-0312
Time frame: 24 months
Time of Maximum Concentration (Tmax)
Time frame: 24 Months
Area Under the Curve (AUC) for Various Time Intervals
Time frame: 24 Months
Half Life (t1/2) for MST-0312
Time frame: 24 Months
Clearance (CL) for MST-0312
Time frame: 24 Months
Percentage of Participants with Anti-Drug Antibodies (ADAs)
Time frame: 24 Months
Objective Response Rate (ORR) by RECIST 1.1 and iRECIST
Time frame: 12 Months
Disease Control Rate (DCR) by RECIST 1.1 and iRECIST
Time frame: 12 Months
Duration of Response (DoR) by RECIST 1.1 and iRECIST
Time frame: 12 Months
Progression Free Survival (PFS) by RECIST 1.1 and iRECIST
Time frame: 12 Months
Best Overall Response (BoR) by RECIST 1.1 and iRECIST
Time frame: 12 Months
Time To Response (TTR) by RECIST 1.1 and iRECIST
Time frame: 12 Months
Progression Free Survival 2 (PFS2) by RECIST 1.1 and iRECIST
Time frame: 48 Months
Overall Survival (OS)
Time frame: 48 Months
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 1 Jun 2026.
- 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.
6 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing MST-0312 and Pembrolizumab in people with Cancer-Neoplasms, run by Mestag Therapeutics Limited at 6 sites in Spain.
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 4 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 1 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 6 sites in Spain. 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 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.
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 Mestag MST-0312-1001 (+447721893628, medical@mestagtx.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of Dose-limiting Toxicities (DLTs) (time frame: From baseline to end cycle 1. A complete treatment cycle is defined as 21 calendar days.). The study lists 2 primary outcomes in all. 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 1 Jun 2026.