A Phase II, Open-Label Randomized Study of Intravenous Tambiciclib in Combination with the Standard of care Venetoclax and Azacitidine in Patients with Newly Diagnosed AML Who Failed to Achieve at Least MLFS After the First Two Cycles of Treatment with Venetoclax and Azacitidine Alone

2025-524308-31-00 Protocol IRST204.09 Therapeutic exploratory (Phase II) Authorised, recruitment pending

Status Authorised, recruitment pending · 2 EU/EEA countries · 10 sites · Protocol IRST204.09

Overview

Sponsor-declared trial summary

Phase Therapeutic exploratory (Phase II)
Status Authorised, recruitment pending
Participants planned 40
Countries 2
Sites 10

Acute myeloid leukemia

To evaluate efficacy of Tambiciclib as an add on to standard VEN+AZA therapy in patients who did not respond with at least MLFS to the first two cycles of treatment with standard Ven+Aza therapy.

Key facts

Sponsor
Istituto Romagnolo Per Lo Studio Dei Tumori Dino Amadori IRST S.r.l., IIS La Fe
Participant type
Patients
Age range
18-64 years, 65+ years
Gender
Male and Female
Therapeutic area
Diseases [C] - Neoplasms [C04]
Decision date (initial)
2026-05-19
Transition trial
No
Low-intervention
No
Rare-disease indication
Yes
Vulnerable population
No
Funding sources
SELLAS Life Sciences

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Efficacy, Therapy, Safety

To evaluate efficacy of Tambiciclib as an add on to standard VEN+AZA therapy in patients who did not respond with at least MLFS to the first two cycles of treatment with standard Ven+Aza therapy.

Secondary objectives 3

  1. To evaluate the safety and tolerability of Tambiciclib in combination with VEN+AZA
  2. To compare event-free survival (EFS) between patients treated with or without Tambiciclib.
  3. To compare overall survival (OS) between patients treated with or without Tambiciclib.

Conditions and MedDRA coding

Acute myeloid leukemia

VersionLevelCodeTermSystem organ class
28.1 LLT 10000886 Acute myeloid leukemia 10029104

Regulatory references

Plan to share IPD
No
EU CT numberTitleSponsor
2026-525453-36-00 IMPD-Q-only application Sellas Life Sciences Group Inc.

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 14

  1. Male or female ≥ 18 years
  2. Patients must have histologically or cytologically confirmed acute myeloid leukemia according to WHO2022 or ICC2022 definition. Patients must have ≥20 % blasts in the bone marrow and/or blood at diagnosis (excepting AML with defining genetic abnormalities according to WHO 2022).
  3. Patients should have received exactly 2 courses of the SOC venetoclax + azacitidine before study entry.
  4. Patients must have an insufficient response from standard of care treatment, defined as not having achieved at least morphological leukemia free state after course 2 of venetoclax + azacitidine (standard of care).
  5. Patients must have measurable disease, defined as at least 5% of bone marrow blast at the time of enrollment; extramedullary-only disease is excluded. Patients must have measurable disease, defined as at least 5% of bone marrow blast at the time of enrollment; extramedullary-only disease is excluded.
  6. ECOG performance status <2
  7. Patients must have normal organ function (- Total bilirubin ≤ 1.5 × upper limit of normal (ULN) except for patients with Gilbert’s syndrome, who are included if total bilirubin is < 3 × ULN or if direct bilirubin is < 1.5 × ULN. - Aspartate aminotransferase (AST), alanine aminotransferase (ALT) ≤ 2.5 × ULN. For those with known or suspected disease liver infiltration, AST and ALT ≤ 5 × ULN. - Measured or calculated (determined by the Cockcroft-Gault equation) serum creatinine clearance (CrCl) ≥ 50 mL/min (glomerular filtration rate can be alternative to CrCl) Whether the value is calculated by equation or measured directly can be based on institutional standard practice.)
  8. Peripheral WBC counts < 25,000/µL. Cytoreduction prior to study will be allowed with hydroxyurea; hydroxyurea use will also be permitted during treatment period in patients with proliferative, progressive disease. Use of leukapheresis for the purpose of lowering WBC counts to make the patient eligible for enrolment is not permitted.
  9. Recovery to grade ≤1 from adverse events related to the ongoing Ven+Aza SOC therapy occurring during the first two cycles of SOC except alopecia, fatigue, endocrinopathies and lab abnormalities controlled with medical therapy, and/or hematological toxicity.
  10. Female patients of childbearing potential (WOBC) must accept and be compliant with a highly effective contraceptive method (APPENDIX F) during treatment and up to 6 months after last administration of study drug. Since no sufficient data are available on the interaction between tambiciclib and hormonal contraceptives, if hormonal contraceptive methods are used, also a barrier method (condom) is required.
  11. For woman of childbearing potential (WOCBP), a negative serum pregnancy test must be confirmed prior to first dose.
  12. Male patients whose partner is a pregnant woman or a WOBC must use a condom during treatment and up to 3 months after last administration of study drug.
  13. WOBC and male patients whose partner is a pregnant woman or a WOBC must be informed and must accept and be compliant with no gamete donation (sperm/egg) during treatment and through the full contraception follow up period.
  14. Participant is willing and able to give informed consent for participation in the study.

Exclusion criteria 18

  1. Systemic therapy for AML (excluding ATRA if used for suspected APL, or hydroxyurea or cytarabine if used emergently for emergent cytoreduction or disease stabilization (a maximum total cumulative dose of cytarabine 1 g) and Ven+Aza), within 30 days.
  2. Radiotherapy with wide field radiation within 28 days or radiotherapy with a limited field of radiation for palliation within 7 days of the first dose.
  3. Symptomatic central nervous system (CNS) involvement. Patients with asymptomatic CNS involvement who are radiologically and neurologically stable ≥ 4 weeks following CNS-directed therapy and are on a stable or decreasing dose of corticosteroids are eligible for study entry.
  4. Receiving any investigational agents in another clinical trial within 30 days prior to study screening.
  5. Ongoing therapy with corticosteroids greater than 25 mg of prednisone or its equivalent per day. Inhaled and topical steroids are allowed.
  6. Uncontrolled hypertension with clinically meaningful episodes such as a history of recurrent hypertensive crisis, or a history of hypertensive encephalopathy.
  7. Severe cardiovascular disease within 6 months of study entry, including any of the following: a. Clinically significant heart disease such as congestive heart failure requiring treatment (NYHA class III or IV), or clinically significant arrhythmia. Subjects with pacemakers are eligible if they have no history of fainting or clinically relevant arrhythmias while using the pacemaker. b. Evidence of acute coronary syndromes (including myocardial infarction, and/or unstable angina). c. Average QTcF ≥ 480 msec on screening ECG. QTcF may be not considered if <500 msec in presence of complete or incomplete branch block or for subjects with pacemakers. Patients with a history of clinically significant venous or arterial thrombotic events that the investigator feels puts the patient at risk for participation in the study (based on overall status, medical history, or other factors) will be excluded.
  8. Concurrent malignancy within 2 years prior to entry other than adequately treated cervical carcinoma-in-situ, localized squamous cell cancer of the skin, basal cell carcinoma, prostate cancer not requiring treatment, ductal carcinoma in situ of the breast, and superficial non-muscle invasive urothelial carcinoma (excluding T1 lesions and CIS).
  9. Known active hepatitis B or hepatitis C virus infection. Patients with chronic HBV infection with active disease who meet the criteria for anti HBV therapy have to be on a suppressive antiviral therapy prior to enrollment. Patients with HCV may be enrolled if the HCV is stable, and the patient is not at risk for hepatic decompensation.
  10. Patients with known HIV infection except if: - They have CD4+ T-cell (CD4+) counts ≥ 350 cells/uL, and - No history of AIDS-defining opportunistic infections within the last 12 months preceding screening, and - Are on established ART for at least four weeks and have an HIV viral load less than 400 copies/mL prior to enrollment.
  11. Any other uncontrolled intercurrent illness or condition that in the judgement of the investigator may endanger the patient
  12. Concomitant medications that are strong CYP3A4 inhibitors or strong inducers within 7 days prior to the first dose. Avoid consumption of Seville orange (and juice), grapefruit or grapefruit juice, grapefruit hybrids, pomelos, star citrus fruits or St. John’s wort within 7 days of first dose. Given that tambiciclib (SLS009) is a CYP3A4 substrate and the critical role of azole antifungals (commonly strong CYP3A4 inhibitors) in the treatment of patients with AML, if use of azole antifungals is necessary, and if azoles cannot be substituted with alternative antifungal drugs (e.g., caspofungin, amphotericin B etc.), use of isavuconazole, the only azole antifungal that is a moderate CYP3A4 inhibitors and does not prolong QT interval, is recommended. Other azoles are allowed if deemed necessary by the investigator. If azoles are used, patients receiving azole antifungals will adjust venetoclax dosing accordingly and receive enhanced monitoring
  13. Medications that are known to prolong the QT interval that could not be stopped prior to study entry judged by investigator, except azole antifungal medications.
  14. Severe stroke or intracranial hemorrhage within 6 months.
  15. Major surgery within 4 weeks prior to study entry.
  16. Known hypersensitivity to the study drug or excipients of the preparation or any agent given in association with this study.
  17. Pregnant or breast-feeding females.
  18. History of previous exposure to any other CDK9 inhibitors.

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

  1. Difference in Overall response rate (ORR) at course 2 defined as Complete response (CR) rate + Complete hematological response (CRh) + complete response with incomplete hematologic recovery (CRi) rate + Morphologic leukemia free state (MLFS) rate according ELN 2022 definition.

Secondary endpoints 3

  1. Proportion of patients experiencing adverse events (AE) and severe adverse events (SAE) graded according to NCI-CTCAE 5.0.
  2. Event-free survival defined as time from C1D1 to treatment failure, relapse or death from any reason. Treatment failure is defined as lack of response (no achievement of at least MLFS) after second treatment cycle.
  3. Overall survival defined as time from C1D1 to death from any reason.

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 2

TAMBICICLIB 100 mg/20 mL, Solution for Injection

PRD13394278 · Product

Active substance
Tambiciclib
Substance synonyms
4-[[[4-[5-Chloro-2-[[trans-4-[[(1R)-2-methoxy-1-methyl-ethyl]amino]cyclohexyl]amino]-4-pyridinyl]-2-thiazolyl]amino]methyl]tetrahydro-2H-pyran-4-carbonitrile, SLS009, GFH009
Pharmaceutical form
SOLUTION FOR INJECTION/INFUSION
Route of administration
INTRAVENOUS INFUSION
Max daily dose
30 mg milligram(s)
Max total dose
30 mg milligram(s)
Max treatment duration
8 Day(s)
Authorisation status
Not Authorised
MA holder
IRST IRCCS
Paediatric formulation
No
Orphan designation
No

TAMBICICLIB 100 mg/10 mL, Solution for Injection

PRD13422875 · Product

Active substance
Tambiciclib
Substance synonyms
4-[[[4-[5-Chloro-2-[[trans-4-[[(1R)-2-methoxy-1-methyl-ethyl]amino]cyclohexyl]amino]-4-pyridinyl]-2-thiazolyl]amino]methyl]tetrahydro-2H-pyran-4-carbonitrile, SLS009, GFH009
Pharmaceutical form
SOLUTION FOR INJECTION/INFUSION
Route of administration
INTRAVENOUS INFUSION
Max daily dose
30 mg milligram(s)
Max total dose
30 mg milligram(s)
Max treatment duration
8 Day(s)
Authorisation status
Not Authorised
MA holder
IRST IRCCS
Paediatric formulation
No
Orphan designation
No

Auxiliary 2

Venetoclax

SCP16272936 · ATC

Active substance
Venetoclax
Substance synonyms
ABT-199, GDC-0199, 4-(4-((2-(4-CHLOROPHENYL)-4,4-DIMETHYLCYCLOHEX-1-EN-1-YL)METHYL)PIPERAZIN-1-YL)-N-((3-NITRO-4-((TETRAHYDRO-2H-PYRAN-4-YLMETHYL)AMINO)PHENYL)SULFONYL)-2-(1H-PYRROLO(2,3-B)PYRIDIN-5-YLOXY)BENZAMIDE
Route of administration
ORAL
Max daily dose
400 mg milligram(s)
Max total dose
400 mg milligram(s)
Max treatment duration
28 Day(s)
Authorisation status
Authorised
ATC code
L01XX52 — VENETOCLAX
Marketing authorisation
-
Paediatric formulation
No
Orphan designation
No
Modified vs. Marketing Authorisation
No

Azacitidine

SCP184620 · ATC

Active substance
Azacitidine
Route of administration
SUBCUTANEOUS INJECTION
Max daily dose
75 mg/m2 milligram(s)/square meter
Max total dose
75 mg/m2 milligram(s)/square meter
Max treatment duration
7 Day(s)
Authorisation status
Authorised
ATC code
L01BC07 — AZACITIDINE
Marketing authorisation
-
Paediatric formulation
No
Orphan designation
No
Modified vs. Marketing Authorisation
No

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Istituto Romagnolo Per Lo Studio Dei Tumori Dino Amadori IRST S.r.l.

Sponsor organisation
Istituto Romagnolo Per Lo Studio Dei Tumori Dino Amadori IRST S.r.l.
Address
Via Piero Maroncelli 40
City
Meldola
Postcode
47014
Country
Italy

Scientific contact point

Organisation
Istituto Romagnolo Per Lo Studio Dei Tumori Dino Amadori IRST S.r.l.
Contact name
Clinical trials Coordinating Center

Public contact point

Organisation
Istituto Romagnolo Per Lo Studio Dei Tumori Dino Amadori IRST S.r.l.
Contact name
Clinical trials Coordinating Center

IIS La Fe

Sponsor organisation
IIS La Fe
Address
Avenida De Fernando Abril Martorell 106 A 7 Planta
City
Valencia
Postcode
46026
Country
Spain

Public contact point

Organisation
Istituto Romagnolo Per Lo Studio Dei Tumori Dino Amadori IRST S.r.l.
Contact name
Clinical Trial Coordinating center

Sponsor responsibilities

Article 77 compliance
Istituto Romagnolo Per Lo Studio Dei Tumori Dino Amadori IRST S.r.l.
Contact point sponsor
Istituto Romagnolo Per Lo Studio Dei Tumori Dino Amadori IRST S.r.l.
Article 77 implementation
Istituto Romagnolo Per Lo Studio Dei Tumori Dino Amadori IRST S.r.l.

Locations

2 EU/EEA countries · 10 investigational sites

By country

CountryMS statusPlanned subjectsSites
Italy Authorised, recruitment pending 20 5
Spain Authorised, recruitment pending 20 5
Rest of world 0

Investigational sites

Italy

5 sites · Authorised, recruitment pending
Azienda Unita Sanitaria Locale Della Romagna
Hematology, Viale Vincenzo Randi 5, 48121, Ravenna
Azienda Ospedaliera Di Rilievo Nazionale Antonio Cardarelli
Hematology, Via Antonio Cardarelli 9, 80131, Naples
IRCCS Ospedale Policlinico San Martino
Hematology, Largo Rosanna Benzi 10, 16132, Genoa
Istituto Oncologico Veneto
Oncohematology Unit and Transplant Unit, Via Dei Carpani 16/z, 31033, Castelfranco Veneto
Istituto Romagnolo Per Lo Studio Dei Tumori Dino Amadori IRST S.r.l.
Oncohematology, Via Piero Maroncelli 40, 47014, Meldola

Spain

5 sites · Authorised, recruitment pending
Hospital Universitario Y Politecnico La Fe
Servicio de Hematología, Avenida Fernando Abril Martorell 106, 46026, Valencia
Consorcio Hospital General Universitario De Valencia
Servicio de Hematología, Avenida Tres Cruces 2, 46014, Valencia
Hospital General Universitario Dr. Balmis
Servicio de Hemotología, Avinguda Del Pintor Baeza 12, 03010, Alicante
Hospital Arnau De Vilanova De Valencia
Servicio de Hematología, Calle De San Clemente 12, 46015, Valencia
Hospital General Universitario De Albacete
Servicio de Hematología, Calle Hermanos Falco 37, 02006, Albacete

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 14 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

TypeTitleVersion
Protocol (for publication) 20409_Prot_changes_RFI004 2.0
Protocol (for publication) D1_20409_Prot_2025-524308-31-00_PUB 2.0
Protocol (for publication) D4_20409_Quest_HM-PRO_EN_PUB 1
Protocol (for publication) D4_20409_Quest_HM-PRO_ES_PUB 1
Protocol (for publication) D4_20409_Quest_HM-PRO_IT_PUB 1
Recruitment arrangements (for publication) K1_20409_Recru_EN_PUB 1
Recruitment arrangements (for publication) K1_Recruitment arrangements_redacted 1
Subject information and informed consent form (for publication) L1 _SIS and ICF_EMBARAZO_redacted 1
Subject information and informed consent form (for publication) L1 _SIS and ICF_ES_redacted 2
Subject information and informed consent form (for publication) L1_20409_ICF_IT_PUB 4.0
Subject information and informed consent form (for publication) L2_20409_Privacy_IT_PUB 1.0
Synopsis of the protocol (for publication) D1_20409_ProtSyn_2025-524308-31-00_EN_PUB 2.0
Synopsis of the protocol (for publication) D1_20409_ProtSyn_2025-524308-31-00_ES_PUB 2.0
Synopsis of the protocol (for publication) D1_20409_ProtSyn_2025-524308-31-00_IT_PUB 2.0

Application history

1 submissions — initial application plus substantial / non-substantial modifications

#TypeCodeSubmittedReference MSConclusionDecision date
1 INITIAL IN 2026-02-03 Spain Acceptable with conditions
2026-05-14
2026-05-19