A Study of Avapritinib in Patients with Indolent and Smoldering Systemic Mastocytosis

Recruitment & Eligibility

Status: Authorised-recruitment may be ongoing or finished

Sex: All

Target Recruitment: 244

Inclusion Criteria

1. Patients must be = 18 years of age.
2. Patient must have SM, confirmed by Central Pathology Review of BM biopsy, and central review of B- and C-findings by WHO diagnostic criteria.
3. Patient must have moderate-to-severe symptoms based on minimum mean TSS over the 14-day eligibility screening period for assessment of TSS. Minimum TSS for eligibility is = 28.
4. Patient must have failed to achieve adequate symptom control for 1 or more Baseline symptoms, as determined by the Investigator, with at least 2 of the following symptomatic therapies: H1 blockers, H2 blockers, proton-pump inhibitors, leukotriene inhibitors, cromolyn sodium, corticosteroids, or omalizumab.
5. The patient's symptomatic SM therapies (eg, H1 and H2 blockers) must be stable (same dose, no new medications =14 days before beginning the 14-day ISM-SAF eligibility TSS assessment).
6. If the patient is receiving corticosteroids, the dose must be =20 mg/day prednisone or equivalent, and the dose must be stable for =14 days before beginning the 14-day ISM-SAF eligibility TSS assessment.
7. Patient must have an Eastern Cooperative Oncology Group Performance Status of 0 to 2.
8. Patient must be able to give written informed consent.
Are the trial subjects under 18? no
Number of subjects for this age range:
F.1.2 Adults (18-64 years) yes
F.1.2.1 Number of subjects for this age range 200
F.1.3 Elderly (>=65 years) yes
F.1.3.1 Number of subjects for this age range 44

Exclusion Criteria

1. Patient has been diagnosed with any of the following WHO SM subclassifications: Cutaneous mastocytosis only, SM-AHN, SSM, ASM, MCL, MC sarcoma.
2. Patient has been diagnosed with another myeloproliferative disorder.
3. Patient has any of the following organ damage C-findings attributable to SM: Cytopenia, Hepatomegaly with ascites and impaired liver function, Palpable splenomegaly with hypersplenism, Malabsorption with hypoalbuminemia and significant weight loss, Skeletal lesions: large osteolytic lesions with pathologic fractures, Life-threatening organ damage in other organ systems that is caused by MC infiltration in tissues.
4. Patient meets any of the following laboratory criteria: Aspartate aminotransferase or alanine aminotransferase > 3.0 × ULN, Total bilirubin > 1.5 × ULN; > 3.0 × ULN if due to Gilbert's disease. (In the case of Gilbert's disease, a direct bilirubin > 2.0 × ULN is an exclusion.) Albumin < 1 × LLN, eGFR < 30 mL/min/1.73 m^2 or creatinine clearance or creatinine > 1.5 × ULN
Absolute neutrophil count < 1.5 × 10^9/L, Hemoglobin < 10 g/dL, Platelet count < 100,000/µL
5. Patient has received any of the following medications, therapies, or procedures in the timeframes listed: Any prior treatment with avapritinib, Any TKI, including but not limited to masitinib and midostaurin, or investigational agent for < 14 days or 5 half-lives of the drug (whichever is longer) before beginning the 14-day ISM-SAF eligibility TSS assessment, Any antineoplastic drug therapy < 28 days or 5 half-lives of the drug (whichever is longer) before beginning the 14- day ISM-SAF eligibility TSS assessment,
Radiotherapy or psoralen and ultraviolet A (PUVA) therapy < 14 days before beginning the 14-day ISM-SAF eligibility TSS assessment, Any hematopoietic growth factor < 14 days before beginning the 14-day ISM-SAF eligibility TSS assessment, Any major surgical procedure < 14 days before starting the ISM-SAF for determination of eligibility.
6. Patient requires therapy with a concomitant medication that is a strong inhibitor, strong inducer, or moderate inducer of cytochrome P450 3A4 (CYP3A4) (see Appendix 9).
7. Patient has a history of a malignancy that has been diagnosed or required therapy within 3 years before the first dose of study drug. Patients with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational agent may be included after approval by medical monitor.
8. Patient has a QTcF > 480 msec.
9. Patient has a history of a seizure disorder (eg, epilepsy) or requires antiseizure medication.
10. Patient has a history of a cerebrovascular accident or transient ischemic attacks within 12 months before the first dose of study drug.
11. Patient has a known risk or recent history (12 months before the first dose of study drug) of ICB (eg, brain aneurysm).
12. Patient has a primary brain malignancy or metastases to the brain.
13. Patient has clinically significant, uncontrolled cardiovascular disease, including Grade III or IV congestive heart failure greater than New York Heart Association classification II; myocardial infarction or unstable angina within the previous 6 months; clinically significant, uncontrolled arrhythmias, or uncontrolled hypertension.
14. Female patients who are unwilling, if not postmenopausal or surgically sterile, to abstain from sexual intercourse or employ highly effective contraception

Study & Design

Study Type: Interventional clinical trial of medicinal product

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method

Secondary Outcome Measures

Name	Time	Method

Related Trials