Table 1 Summarized clinical, laboratory, histological, and molecular characteristics of 13 KIT D816V positive advanced systemic mastocytosis patients prior to treatment based on response pattern in single-cell-derived myeloid progenitor cells (CFU-GM colonies, relative reduction of KIT D816V positive colonies), three cohorts were defined: midostaurin + avapritinib responder (cohort #1), midostaurin non-responder + avapritinib-responder (cohort #2), and midostaurin + avapritinib non-responder (cohort #3)

From: Inhibitory effects of midostaurin and avapritinib on myeloid progenitors derived from patients with KIT D816V positive advanced systemic mastocytosis

 

Initial

Cohort #1

Cohort #2

Cohort #3

Number of patients

13

4

3

4

Age in years; median (range)

67 (48–79)

58 (48–79)

76 (75–78)

64 (61–67)

Male, n (%)

11 (85)

3 (75)

3 (100)

3 (75)

C-findingsa

  C-findings, n; median (range)

3 (2–4)

3 (2–4)

3 (2–3)

3 (2–4)

  Hemoglobin, g/dL; median (range)

9.9 (7.1–15.0)

10.8 (7.1–15.0)

9.4 (8.8–12.0)

11.7 (9.1–13.9)

   < 10 g/dL, n (%)

7 (54)

2 (50)

2 (67)

1 (25)

  Platelets, ×109 /L; median (range)

110 (29–426)

190 (29–425)

108 (80–315)

117 (47–426)

   < 100 × 109 /L, n (%)

5 (38)

1 (25)

1 (33)

2 (50)

  ANC, ×109 /L; median (range)

7.5 (1.0–60.0)

8.7 (1.7–12.6)

1.3 (1.0–6.1)

16.4 (6.2–60.6)

   < 1 × 109 /L, n (%)

0 (0)

0 (0)

0 (0)

0 (0)

  Alkaline phosphatase, U/L; median (range)

376 (41–707)

204 (41–707)

409 (303–592)

387 (78–632)

   > 130 U/L, n (%)

11 (85)

3 (75)

3 (100)

3 (75)

  Albumin level, g/L; median (range)

34.5 (30.0–43.0)

33.1 (29.5–40.7)

34.5 (33.6–34.5)

34.6 (33.6–42.9)

   < 34 g/L, n (%)

6 (46)

2 (50)

1 (33.3)

2 (50)

  Weight loss (>10% over last 6 months), n (%)

8 (62)

4 (100)

1 (33.3)

3 (75)

B-findings

  MC-infiltration in BM biopsy, %, median (range)

35 (20–70)

30 (20–50)

50 (20–60)

20 (20–50)

  Serum tryptase level, µg/L; median (range)

140 (33–739)

104 (40 –194)

213 (128–739)

173 (102–225)

  Organomegalyb, n (%)

12 (92)

3 (75)

3 (100)

3 (100)

Other relevant findings

  Leukocytes, × 109/L median (range)

10.8 (2.2–87.0)

12 (3.9–15.4)

3.4 (2.2–8.9)

20.7 (9.1–86.6)

  Monocytes, × 109/L median (range)

0.8 (0.2-6.9)

0.5 (0.4–0.6)

0.5 (0.3–1)

1.5 (0.2–6.9)

  Eosinophils, × 109/L median (range)

0.4 (0.1–3.6)

0.2 (0.1–0.3)

0.45 (0.1–1.2)

1.5 (1.5–1.5)

  KIT D816V EAB in PB, %, median (range)

40 (18–55)

27 (18–47)

41 (40–43)

51 (40–55)

  Additional mutations besides KIT D816Vc

2 (0–5)

1 (0–1)

2 (2–3)

4 (2–5)

  1. ANC absolute neutrophil count, BM bone marrow, EAB expressed allele burden, MC mast cell, PB peripheral blood
  2. aNon-measurable C-findings (e.g., ascites and osteolytic lesions) were excluded
  3. bOrganomegaly including hepatomegaly, splenomegaly and/or lymphadenopathy
  4. cAdditional mutations were detected using targeted sequencing panel to investigate 18 candidate genes
Back to article page