A Phase 2 Study of PTX-100 Monotherapy in Patients with r/r CTCL

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Prescient Therapeutics Limited

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Neoplasms [C04]

Trial duration

22 Jan 2026 → ongoing

Decision date (initial)

2025-12-08

Transition trial

No

Low-intervention

No

Rare-disease indication

Yes

Vulnerable population

Yes

Funding sources

Prescient Therapeutics Ltd

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Others, Safety, Pharmacokinetic, Efficacy

To determine the efficacy of PTX-100

Secondary objectives 3

1. To further characterize the efficacy of PTX-100
2. To determine safety and tolerability of PTX-100
3. To characterize the PK of PTX-100 in both parts of the study (2a and 2b)

Conditions and MedDRA coding

Cutaneous T-Cell Lymphoma

Study design 2 periods

Regulatory references

Scientific advice from competent authorities

Food And Drug Administration

Plan to share IPD

No

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 15

1. Adult patient ≥18 years of age
2. Patient is capable of giving adequate signed informed consent
3. Have a confirmed diagnosis of CTCL with histological confirmation of: a. Mycosis fungoides (MF) OR b. Sezary syndrome (SS) c. Other CTCL subtypes may be permitted after discussion with the medical monitor. NOTE: Histopathology confirmation of CTCL is based on ISCL/EORTC criteria
4. Patients must have greater than or equal to Stage IB disease for MF/SS subtypes. For non MF/non SS subtypes, must have at least T2 disease based on ISCL/EORTC criteria and consideration for inclusion into the study must first be discussed with the medical monitor. (ref: Olsen EA et al. Blood 140 (5); 2022)
5. Has received and failed (or intolerant of) at least 2 prior lines of prior systemic therapy for their disease. Systemic therapies can include any of the following: INF-α, chemotherapy agent such as methotrexate, histone deacetylase inhibitors, antibody drug conjugates, monoclonal antibodies or a prior investigational agent.
6. Has measurable disease defined by at least one of the following, within 28 days prior to start of study treatment: a. Skin lesions evaluable by mSWAT >0 (Refer to Revised International Working Group [Olsen 2022]) OR b. Atypical and/or malignant lymphocytes quantifiable by flow cytometry or morphology in blood based on Olsen 2022 staging criteria OR c. Extracutaneous disease measurable by Lugano Criteria
7. On a stable dose of systemic corticosteroid (≤10 mg prednisone or equivalent) are permitted. Participants on a stable dose of topical corticosteroids are permitted.
8. Washout period- must be 2 weeks (4 weeks for monoclonal antibodies) or 5 -half-lives (whichever is longer) since any prior anti-cancer therapy
9. Must be human T-cell lymphotropic virus type 1 (HTLV1) negative.
10. Has an ECOG PS of 0 to 2.
11. Life expectancy of 3 months or greater
12. Has adequate bone marrow function as defined below: • Absolute neutrophil count (ANC) ≥ 1.0×109/L (without growth factors). • Platelet count ≥ 50×109/L • Hemoglobin ≥ 8.0 g/dL (without erythroid stimulating agents)
13. Has adequate hepatic function as defined below: •Total bilirubin ≤ 1.5 × upper limit of normal (ULN)(Patients with Gilbert’s Syndrome or hepatic involvement may be eligible at the Investigator’s discretion in consultation with the Medical Monitor if < 3 × ULN) and Alanine aminotransferase ≤ 2.5×ULN • Aspartate aminotransferase ≤ 2.5×ULN
14. Has adequate Renal function as defined below: • Creatinine Calculated or estimated creatinine clearance of ≥ 50 mL/min by Cockcroft-Gault
15. Has adequate coagulation function as defined below: • INR < 1.5 ULN • Activated partial thromboplastin time ≤ 1.5 ULN

Exclusion criteria 11

1. Patients with known central nervous system involvement
2. Significant cardiovascular disease including any of the following: a. Myocardial infarction within 6 months prior to signing informed consent. b. Uncontrolled angina within 3 months prior to signing informed consent. c. Congestive heart failure; New York Heart Association (NYHA) class III or IV, or a history of congestive heart failure NYHA class III or IV. d. QT interval corrected by the Fridericia correction formula (QTcF) >470 msec at screening. e. History of clinically significant ventricular arrhythmias (e.g., ventricular tachycardia, ventricular fibrillation, torsades de pointes). f. History of Mobitz II second-degree or third-degree heart block. g. Uncontrolled hypertension as indicated by a resting systolic blood pressure >160 mm Hg or diastolic blood pressure >90 mm Hg at screening.
3. A history of, or concurrent interstitial lung disease or severely impaired lung function.
4. Active viral, bacterial, fungal infection or other serious infection requiring ongoing systemic treatment. Routine antimicrobial prophylaxis is permitted.
5. Medical history of another malignant tumor within the past 3 years. Exceptions are patients with basal cell carcinoma of the skin, squamous cell carcinoma of the skin or carcinoma in situ who have undergone curative therapy with no evidence of disease.
6. On an immunomodulatory drug for concomitant or intercurrent conditions or who have received any of these agents within 4 weeks of baseline.
7. Patients with active viral (any etiology) hepatitis are excluded. However, patients with serologic evidence of chronic hepatitis B virus (HBV) infection (defined by a positive hepatitis B surface antigen test and a positive anti-hepatitis core antigen antibody test) who have a viral load below the limit quantification (HBV deoxyribose nucleic acid titer < 1000 cps/mL or 200 IU/mL) may be eligible and should be discussed with the Medical Monitor. Patients with a history of hepatitis C virus infection who have completed curative antiviral treatment and have a viral load below the limit of quantification may be eligible and should be discussed with the Medical Monitor.
8. A history or current evidence of any condition, laboratory abnormality or other circumstance that might confound the results of the study or interfere with patient participation for the full duration of the study
9. Prior allogeneic or autologous hematopoietic transplantation
10. Has a known psychiatric disorder that would interfere with compliance with the requirements of the study.
11. Is a consumer of illicit or recreational drugs or has a recent history (within the last year) of drug or alcohol abuse or dependence that in the judgment of the Investigator, would interfere with compliance with the requirements of the study

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. Objective response rate (ORR)

Secondary endpoints 3

1. Further Efficacy: - Skin response as per Modified Severity-Weighted Assessment Tool (mSWAT) - Progression-free survival (PFS) - Duration of response (DOR) - Time to response (TTR) - Complete response rate (CRR) - Overall survival (OS) - Time to next (systemic) treatment (TTNT)
2. Safety and Tolerability - Incidence, severity and nature of adverse events (AEs) - Changes from Baseline in vital signs, electrocardiogram (ECG), clinical laboratory values and Eastern Cooperative Oncology Group (ECOG) performance status (PS)
3. PK: - PK parameters including: Cmax Tmax, Cmin, AUCtau, AUClast, AUCinf, kel, half-life (t1/2), total body CLss, Vzss, Cmax ratio (Rac-Cmax), and AUC Ratio (Rac-AUC) - Population PK model development (NCM) from data of Phase 2a and Phase 2b data - Population and individual patient PK parameters estimation

Investigational products

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

Test 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Prescient Therapeutics Limited

Sponsor organisation

Prescient Therapeutics Limited

Address

Suite 2 Level 11, 385 Bourke Street 385 Bourke Street

City

Melbourne

Postcode

3000

Country

Australia

Scientific contact point

Organisation

Prescient Therapeutics Limited

Contact name

Dr Marissa Lim

Public contact point

Organisation

Prescient Therapeutics Limited

Contact name

James McDonnell

Third parties 7

Locations

2 EU/EEA countries · 6 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

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

Documents 24 files

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

Application history

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