A Study of Topical Duvelisib in Participants With Early-stage Mycosis Fungoides

• Duvelisib (Drug), also known as SBI-0145: Topical gel

Primary outcomes

• Number of Participants with Treatment-emergent Adverse Events (TEAEs) [Baseline through Day 114]
• Local Skin Reactions to Duvelisib Topical Gel [After each treatment administration up to Day 114]: Local skin reactions will be measured as a local skin reaction score using a four-point post-treatment assessment severity scale.
• Maximum Tolerated Dose (MTD) of Duvelisib Topical Gel [Up to 28 days]
• Recommended Phase 2 Dose (RP2D) of Duvelisib Topical Gel [Up to 28 days]

Secondary outcomes

• Pharmacokinetics: Plasma Concentration of Duvelisib Topical Gel [Days 1, 2, and 28 (pre-dose, up to 6 hours post-dose)]
• Pharmacokinetics: Maximum Plasma Concentration (Cmax) of Duvelisib Topical Gel [Days 1, 2, and 28 (pre-dose, up to 6 hours post-dose)]
• Pharmacokinetics: Time to Maximum Plasma Concentration (Tmax) of Duvelisib Topical Gel [Days 1, 2, and 28 (pre-dose, up to 6 hours post-dose)]
• Pharmacokinetics: Area Under the Curve (AUC) of Duvelisib Topical Gel [Days 1, 2, and 28 (pre-dose, up to 6 hours post-dose)]
• Proportion of Treated Lesions Achieving >50% Improvement from Baseline Based on Modified Composite Assessment of Index Lesion Severity (mCAILS) Score [Baseline through Day 114]
• Number of Participants Achieving a ≥50% Reduction from Baseline in Total mCAILS Score [Baseline through Day 114]
• Change from Baseline in Total Modified Severity-weighted Assessment Tool (mSWAT) Score [Baseline, Day 114]

Sex: All, ages: 18 Years to any

Key Inclusion Criteria:

* Have a clinical diagnosis of Stage IA, Stage IB, or Stage IIA mycosis fungoides (cutaneous T-cell lymphoma), without clinically significant lymphadenopathy (≥1.5 centimeters).
* Have 3 to 5 active, treatment-accessible mycosis fungoides lesions; ulcerated lesions and lesions to the face, neck, inguinal folds and intergluteal cleft are not considered suitable for administration of study drug.
* Have baseline organ function (without transfusion support within 30 days of Cycle 1 Day 1) as defined by the protocol.

Key Exclusion Criteria:

* Have Stage IIB to IVB mycosis fungoides or Sezary syndrome.
* Have histopathologically confirmed lymph node involvement.
* Received systemic treatment with a phosphoinositide 3-kinases inhibitor in the 60 days prior to starting study drug.
* Received topical steroids or other topical treatment (for example, nitrogen mustard) on mycosis fungoides lesions in the 2 weeks prior to starting study drug. Participants who receive such agents may become eligible for the study after a 14-day washout period.
* Received systemic steroids, immunosuppressants (for example, cyclosporine, prednisone), psoralen ultraviolet A radiation therapy, narrow-band ultraviolet B light therapy, carmustine or other systemic therapies for mycosis fungoides in the 3 weeks prior to starting study drug.
* Received electron beam irradiation within the 3 months prior to starting study drug.

Note: other protocol-defined criteria apply.

• Reuven Chantre, MD, Study director, Secura Bio, Inc.