Masitinib for the Treatment of Severe Mast Cell Activation Syndrome

AB Science

Status and phase: Enrolling; Phase 2

Conditions: Mast Cell Activation Syndrome

Treatments: Drug: Masitinib 4.5 mg/kg/day; Drug: Masitinib 6.0 mg/kg/day; Drug: Placebo; Other: Best supportive care

Study type: Interventional

Funder types: Industry

Identifiers

NCT05449444

AB20006

2021-005406-96 (EudraCT Number)

Details and patient eligibility

About

To evaluate the efficacy and safety of two dosing schemes of oral masitinib versus matching placebo in the treatment of patients suffering from severe MCAS with handicap unresponsive to optimal symptomatic treatment.

Full description

Multicenter, double-blind, placebo-controlled trial comparing two different dosing schemes over a 24-week treatment period.

Dosing scheme #1: Oral masitinib treatment at 3 mg/kg/day for 4 weeks, then a switch to 4.5 mg/kg/day for the remainder of the treatment period, versus placebo with a matching titration scheme. Randomization 2: 1 (Masitinib MCAS: Placebo MCAS).

Dosing scheme #2: Oral masitinib treatment at 3 mg/kg/day for 4 weeks, then a switch to 4.5 mg/kg/day for 4 weeks, then a second switch to 6 mg/kg/day for the remainder of the treatment period versus placebo treatment with a matching titration scheme. Randomization 2: 1 (Masitinib MCAS: Placebo MCAS)

Enrollment: 72 estimated patients

Sex: All

Ages: 18 to 75 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria include:

• Patient with mast cell activation syndrome (MCAS).
• Patient with severe symptoms over the 14-day run-in period defined as at least one of the following: Pruritus score ≥ 9; Number of flushes per week ≥ 8; Hamilton rating scale for depression (HAMD-17) score ≥ 19
• Patient with documented treatment failures of his/her handicap(s) (within last two years) with at least two of the symptomatic treatments used at optimized dose.
• Patients must be on a stable dose of Anti-H1 for a minimum of 4 weeks before screening and should remain at a stable dose throughout the study period.

Exclusion Criteria include:

• Previous treatment with any Tyrosine Kinase Inhibitor.
• Any change in the symptomatic treatment of MCAS, including systemic corticosteroids, or administration of any new treatment for MCAS within 4 weeks prior to screening.
• Patient with systemic indolent mastocytosis.
• Female patients who are pregnant or are breastfeeding.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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72 participants in 3 patient groups, including a placebo group

Masitinib (4.5) & BSC

Experimental group

Description:

Masitinib 4.5 mg/kg/day administered as an add-on to optimal concomitant symptomatic treatment (i.e. best supportive care, BSC). Participants receive masitinib (3.0 mg/kg/day) for 4 weeks, given orally twice daily, with a dose escalation to 4.5 mg/kg/day for the remainder of the treatment period. Each ascending dose titration is subjected to a safety control.

Treatment:

Other: Best supportive care

Drug: Masitinib 4.5 mg/kg/day

Masitinib (6.0) & BSC

Experimental group

Description:

Masitinib 6.0 mg/kg/day administered as an add-on to optimal concomitant symptomatic treatment (i.e. best supportive care, BSC). Participants receive masitinib (3.0 mg/kg/day) for 4 weeks, given orally twice daily, with a dose escalation to 4.5 mg/kg/day for4 weeks of treatment, then a second dose escalation to 6 mg/kg/day for the remainder of the treatment period. Each ascending dose titration is subjected to a safety control.

Treatment:

Other: Best supportive care

Drug: Masitinib 6.0 mg/kg/day

Placebo & BSC

Placebo Comparator group

Description:

Placebo administered as an add-on to optimal concomitant symptomatic treatment (i.e. best supportive care, BSC). Participants receive a matched dose placebo, given orally twice daily.

Treatment:

Other: Best supportive care

Drug: Placebo