Advanced Cancers (Breast, Ovarian, mCRPC, Pancreatic Ductal Adenocarcinoma (PDAC), Brain Mets) With Specific Mutations (Homologous Recombination Deficiency)Phase 1NCT06458712
Study to Assess Safety, Tolerability and Activity of DSB2455 in Participants With Advanced Malignancies
A Phase 1 study testing DSB2455 in people with Advanced Cancers (Breast, Ovarian, mCRPC, Pancreatic Ductal Adenocarcinoma (PDAC), Brain Mets) With Specific Mutations (Homologous Recombination Deficiency), run by Duke Street Bio Ltd at 21 sites in 5 countries.
Trial summary
Open label, multi-centre, Phase Ia/b adaptive design study with an initial 2-stage Dose Escalation Phase followed by a Dose Expansion Phase. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Advanced Cancers (Breast, Ovarian, mCRPC, Pancreatic Ductal Adenocarcinoma (PDAC), Brain Mets) With Specific Mutations (Homologous Recombination Deficiency)
- What is being tested?
- DSB2455
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 180 participants
- Where
- 21 sitesin 5 countries
- Study dates
- 21 Nov 2024to Dec 2028
- 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
- The participant (or legally acceptable representative, if applicable) provides written informed consent for the study.
- Aged ≥18 years of age on the day of signing the informed consent.
- Histologically confirmed diagnosis of locally advanced and/or metastatic breast cancer, prostate cancer (mCRPC), ovarian cancer, or pancreatic ductal adenocarcinoma (PDAC) with confirmed gene alterations/ mutations as defined in the protocol
- Has received prior cancer treatment as outlined in the protocol
- Has measurable disease per RECIST v1.1, or non-measurable disease as defined in the protocol.
- ECOG performance status of 0 to 1.
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- Life expectancy >12 weeks.
- Adequate organ function as defined in the protocol.
- Willing and able to comply with scheduled visits (including follow-up visits), and protocol procedures.
- Willing and able to undergo imaging procedures as per protocol.
- Willing to provide blood samples for correlative research purposes.
- Able to swallow oral medication as an intact dosage form.
- Prior intervention with an approved non-selective PARP inhibitor is permitted in Dose Escalation only.
- Has received prior cancer treatment as outlined in the protocol, dependent on disease type.
- Known asymptomatic or symptomatic brain metastasis, as confirmed by an MRI brain scan, from a primary tumour and meeting the eligibility for the disease types noted above (Dose Expansion only, specific Cohort).
Who cannot join
- Myelodysplastic syndrome (MDS), acute myeloid leukaemia (AML) or features suggestive of MDS/AML.
- Has received a prior PARP1-selective inhibitor.
- Has received prior systemic anti-cancer therapy including investigational agents or device within 2 or 4 weeks prior to study intervention, dependent on the treatment.
- Received prior radiotherapy within 2 weeks of the start of study intervention or has a history of radiation pneumonitis.
- Diagnosis of immunodeficiency or receiving chronic systemic steroid therapy (exceeding 10 mg daily of prednisone equivalent) or any other form of immunosuppressive therapy within 7 days prior to the first dose of study drug.
- Has received a live or live-attenuated vaccine within 30 days prior to the first dose of study intervention. Note: administration of killed vaccines are allowed.
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- Has had an allogeneic tissue/solid organ transplant.
- Has an active autoimmune disease that has required systemic intervention in the past 2 years (i.e., with use of disease modifying agents, corticosteroids or immunosuppressive drugs).
- History of (non-infectious) pneumonitis/interstitial lung disease that required steroids or has current pneumonitis/interstitial lung disease.
- Refractory nausea and vomiting, impairment of gastrointestinal (GI) function or GI disease that may significantly alter the absorption of study drugs.
- Undergone major surgery, open biopsy or significant traumatic injury ≤28 days prior to starting study intervention.
- Has an active infection requiring systemic therapy or an uncontrolled concurrent illness.
- Known history of human immunodeficiency virus (HIV) infection. No HIV testing is required unless mandated by the local health authority.
- Known history of Hepatitis B or known active Hepatitis C virus (HCV)
- Cirrhosis of the liver.
- Clinically significant pulmonary illness.
- Impaired cardiac function or clinically significant cardiac disease.
- Participants with a healing, serious or open wound, ulcer, or bone fracture within 28 days prior to first dose of study intervention.
- History or current evidence of any condition, therapy, or laboratory abnormality, or other circumstance that might confound the results of the study or interfere with the participants involvement for the full duration of the study.
- A WOCBP who has a positive urine pregnancy test (within 72 hours) prior to starting the study intervention. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required.
- Has a known psychiatric or substance abuse disorder that would interfere with the participant's ability to cooperate with the requirements of the study.
- Weight loss of >5% in the 8-week period prior to starting study intervention.
- Known allergy or hypersensitivity to any of the formulation components of DSB2455.
- Has received radiation therapy to the lung that is >30Gy within 6 months of the first dose of study intervention.
- Other disease-specific criteria as outlined in the protocol.
Trial locations and contacts
21 sites in 5 countries. Contact the study team or a site near you to ask about taking part.
21 sites in 5 countries
Spain11 sites, 11 recruiting
- Recruiting
Hospital Universitari Vall d'Hebron
Barcelona
Principal Investigator, +3493 489 30 00, comunica@vhir.org
- Recruiting
START Barcelona, CIOCC, Hospital Universitario Nou Delfos
Barcelona
Principal Investigator, +34 93 254 50 30, tatiana.hernandez@start-barcelona.com
- Recruiting
Hospital Universitario Reina Sofía
Córdoba
Principal Investigator, +34 957 011 464, asuncion.aranda21@gmail.com
- Recruiting
START La Rioja, Hospital Universitario San Pedro
Logroño, La Rioja, 26006
Principal Investigator, +34 941 27 87 60, maria.demiguel@startrioja.com
- Recruiting
Clinica Universidad de Navarra - Madrid
Madrid, 28027
Principal Investigator, +34 913 53 19 20, agonzalezma@unav.es
- Recruiting
Hospital 12 de Octubre
Madrid
Principal Investigator, +34 91 390 80 00, gdevelasco.gdv@gmail.com
- Recruiting
START Madrid-CIOCC, Hospital Universitario HM Sanchinarro
Madrid
Principal Investigator, +34917567825, information@startresearch.com
- Recruiting
Hospital Universitario Virgen de la Victoria
Málaga, 29010
Principal Investigator, +34 671 594 566, fasestempranas@ibima.eu
- Recruiting
Clinica Universidad de Navarra - Pamplona
Pamplona, 31008
Principal Investigator, +34 948 25 54 00, agonzalezma@unav.es
- Recruiting
Universitary Hospital Virgen del Rocio
Seville, 41013
Principal Investigator, +34 62 867 82 09, afalconglez@gmail.com
- Recruiting
Instituto Valenciano de Oncologia
Valencia, 46009
Principal Investigator, +34961114000, dlorente@fivo.org
United States4 sites, 4 recruiting
- Recruiting
The University of Texas M. D. Anderson Cancer Center
Houston, Texas, 77030
Principal Investigator, 713-563-1784, tyap@mdanderson.org
- Recruiting
Yale Cancer Center - Yale New Haven Hospital
New Haven, Connecticut, 06520
Principal Investigator, 203-785-4069, ingrid.palma@yale.edu
- Recruiting
Tisch Cancer Institute Icahn School of Medicine at Mount Sinai
New York, New York, 10029
Principal Investigator, 212-824-7945, Jordan.Cuevas@mssm.edu
- Recruiting
UC Davis Medical Centre
Sacramento, California, 95817
Principal Investigator, 800-282-3284, OCRReferral@health.ucdavis.edu
Poland3 sites, 3 recruiting
- Recruiting
Centrum Terapii Wspolczesnej
Lodz, 90-338
Principal Investigator, +48 42 230 0608, w.laszczewska@ctw.com.pl
- Recruiting
Polish Mother's Memorial Hospital - Research Institute
Lodz
Principal Investigator, +48422711107, ewakalinka@wp.pl
- Recruiting
Uniwersytecki Szpital Kliniczny w Poznaniu
Poznan, 60-569
Principal Investigator, +48 61 854 9040, rramlau@gmail.com
France2 sites, 2 recruiting
- Recruiting
Institut Bergonie
Bordeaux, 33000
Principal Investigator, +33 5 56 33 33 33, d.teyssonneau@bordeaux.unicancer.fr
- Recruiting
Institut Godinot
Reims, 51100
Principal Investigator, +33326504111, camille.mazza@reims.unicancer.fr
Hungary1 site, 1 recruiting
- Recruiting
Orszagos Onkologiai Intezet
Budapest, 1122
Principal Investigator, +3612248600/3211, galgoczy.tunde@oncol.hu
About this study
Official title: Phase Ia/Ib Open Label, Multi-Centre Dose Escalation Study With Expansion Cohorts to Assess the Safety, Tolerability, and Activity of DSB2455 as Monotherapy in Participants With Advanced Malignancies
Open label, multi-centre, Phase Ia/b adaptive design study with an initial 2-stage Dose Escalation Phase followed by a Dose Expansion Phase.
- Being tested
- DSB2455
- Keywords
- BRCA1, BRCA2, PALB2, RAD51B, RAD51C, RAD51D, Breast, Ovarian, Prostate (mCRPC), Pancreatic Ductal Adenocarcinoma (PDAC), Brain Mets/ Metastases
- Medical subject headings
- Anophthalmia with pulmonary hypoplasia, Fanconi Anemia, Complementation Group D1, Fanconi Anemia, Complementation Group N
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DSB2455Drug
PARP1 selective inhibitor
| Study group | Role | What they receive |
|---|---|---|
| DSB2455 Dose Escalation & Expansion | Experimental | DSB2455 Dose Escalation \& Expansion Receives: Drug: DSB2455 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of patients demonstrating dose limiting toxicities and SAEs
Number of patients demonstrating dose limiting toxicities and SAEs
Measured: Through study completion, an average of 1 year
Number of patients exhibiting reduction in tumor size.
Objective Response Rate (ORR)
Measured: Through study completion, an average of 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jun 2024
- Study start21 Nov 2024
- Primary completionAug 2028 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Advanced Cancers (Breast, Ovarian, mCRPC, Pancreatic Ductal Adenocarcinoma (PDAC), Brain Mets) With Specific Mutations (Homologous Recombination Deficiency)Studies 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
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 180 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Duke Street Bio Ltd
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06458712
- Sponsor's protocol ID
- DSB2455-001
- Status last verified
- Sep 2026
- First submitted
- 7 Jun 2024
- Last updated
- 2 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Nelson A, Zheng KF, Wanderley CWS, Michaud DE, Cowley PM, Campbell GM, Kochupurakkal B, Jiao Y, Li CM, Lynce F, Shapiro GI, McGuinness BE, Wise A, Guerriero JL. PARP1-selective inhibitor DSB1559 demonstrates superior efficacy and antitumor immunity in triple-negative breast cancer. J Immunother Cancer. 2026 Oct 7;14(10):e014578. doi: 10.1136/jitc-2025-014578.
PubMed 42843923
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase Ia/Ib Open Label, Multi-Centre Dose Escalation Study With Expansion Cohorts to Assess the Safety, Tolerability, and Activity of DSB2455 as Monotherapy in Participants With Advanced Malignancies
- ClinicalTrials.gov ID
- NCT06458712
- Acronym / sponsor ID
- DSB2455-001
- Keywords
- BRCA1, BRCA2, PALB2, RAD51B, RAD51C, RAD51D, Breast, Ovarian, Prostate (mCRPC), Pancreatic Ductal Adenocarcinoma (PDAC), Brain Mets/ Metastases
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 180 participants (estimated)
- Lead sponsor
- Duke Street Bio LtdIndustry (pharma, biotech, devices)
- Study start
- 21 Nov 2024 (actual)
- Primary completion
- Aug 2028 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 14 Jun 2024 (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.
Open label, multi-centre, Phase Ia/b adaptive design study with an initial 2-stage Dose Escalation Phase followed by a Dose Expansion Phase.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| DSB2455 Dose Escalation & Expansion | Experimental | Drug: DSB2455DSB2455 Dose Escalation \& Expansion |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (15 listed)
- The participant (or legally acceptable representative, if applicable) provides written informed consent for the study.
- Aged ≥18 years of age on the day of signing the informed consent.
- Histologically confirmed diagnosis of locally advanced and/or metastatic breast cancer, prostate cancer (mCRPC), ovarian cancer, or pancreatic ductal adenocarcinoma (PDAC) with confirmed gene alterations/ mutations as defined in the protocol
- Has received prior cancer treatment as outlined in the protocol
- Has measurable disease per RECIST v1.1, or non-measurable disease as defined in the protocol.
Key exclusion criteria (25 listed)
- Myelodysplastic syndrome (MDS), acute myeloid leukaemia (AML) or features suggestive of MDS/AML.
- Has received a prior PARP1-selective inhibitor.
- Has received prior systemic anti-cancer therapy including investigational agents or device within 2 or 4 weeks prior to study intervention, dependent on the treatment.
- Received prior radiotherapy within 2 weeks of the start of study intervention or has a history of radiation pneumonitis.
- Diagnosis of immunodeficiency or receiving chronic systemic steroid therapy (exceeding 10 mg daily of prednisone equivalent) or any other form of immunosuppressive therapy within 7 days prior to the first dose of study drug.
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 |
|---|---|---|
| DSB2455PARP1 selective inhibitor | Drug | DSB2455 Dose Escalation & Expansion |
Primary outcome
Number of patients demonstrating dose limiting toxicities and SAEs
Time frame: Through study completion, an average of 1 year
Number of patients demonstrating dose limiting toxicities and SAEs
Number of patients exhibiting reduction in tumor size.
Time frame: Through study completion, an average of 1 year
Objective Response Rate (ORR)
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 Sep 2026.
- Derived from this study: PubMed 42843923Nelson A, Zheng KF, Wanderley CWS, Michaud DE, Cowley PM, Campbell GM, Kochupurakkal B, Jiao Y, Li CM, Lynce F, Shapiro GI, McGuinness BE, Wise A, Guerriero JL. PARP1-selective inhibitor DSB1559 demonstrates superior efficacy and antitumor immunity in triple-negative breast cancer. J Immunother Cancer. 2026 Oct 7;14(10):e014578. doi: 10.1136/jitc-2025-014578.
- Individual participant dataSharing planned: No
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.
21 sites in 5 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing DSB2455 in people with Advanced Cancers (Breast, Ovarian, mCRPC, Pancreatic Ductal Adenocarcinoma (PDAC), Brain Mets) With Specific Mutations (Homologous Recombination Deficiency), run by Duke Street Bio Ltd at 21 sites in 5 countries.
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 15 inclusion and 25 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 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 21 sites in Spain, United States, Poland, France, Hungary. 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 Duke Street Bio (+44 (0)203 890 8710, clinicaltrials@dukesb.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of patients demonstrating dose limiting toxicities and SAEs (time frame: Through study completion, an average of 1 year). 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?
On the ClinicalTrials.gov record for NCT06458712, which also lists 1 linked publication.
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 Sep 2026.