Table 1. Baseline demographics of patient population.
| Characteristics | All patients (n=48) |
|---|---|
| Median age, years (range) | 69.0 (38–83) |
| Male sex, n (%) | 29 (60) |
| Median time from diagnosis, years (range) | 2.2 (0–26.0) |
| MF classification, n (%) | |
| PMF | 37 (77) |
| Post-PV MF | 6 (13) |
| Post-ET MF | 5 (10) |
| ECOG performance status, n (%) | |
| 0 | 12 (25) |
| 1 | 34 (71) |
| 2 | 2 (4) |
| JAK2 mutation, n (%)a | |
| JAK2V617F-positive | 35 (73) |
| JAK2V617F-negative | 13 (27) |
| Palpable splenomegaly, n (%) | 43 (90) |
| Median palpable spleen size, cm (range)b | 13 (2–24) |
| RBC transfusion dependent, n (%)c | 10 (21)d |
| Median platelet count, × 109/l (range) | 141 (52–859) |
| Median hemoglobin, g/l (range) | 100 (67–139) |
| BMF grade, n (%)e | |
| 0 | 0 |
| 1 | 2 (4) |
| 2 | 15 (31) |
| 3 | 31 (65) |
| Previous treatment, n (%) | 35 (73)f |
| JAK2 inhibitor | 23 (48)g |
| Ruxolitinib | 17 |
| Pacritinib | 4 |
| Fedratinib | 4 |
| AZD1480 | 1 |
| LY-2784544 | 1 |
| Hydroxyurea | 14 (29) |
| Darbepoetin alfa | 4 (8) |
| Pegylated interferon-α2b | 3 (6) |
| Danazol | 3 (6) |
Abbreviations: BMF, bone marrow fibrosis; ECOG, Eastern Cooperative Oncology Group; ET, essential thrombocythemia; JAK, Janus-activated kinase; MF, myelofibrosis; PMF, primary myelofibrosis; PV, polycythemia vera; RBC, red blood cell.
Information regarding other mutations (for example, CALR (calreticulin gene) or MPL (myeloproliferative leukemia virus oncogene)) was not available in this study.
In patients with palpable splenomegaly (n=43).
RBC transfusion dependency defined as transfusions of ⩾6 units of packed RBCs in the 12 weeks before study enrollment for a hemoglobin level of <85 g/l, in the absence of bleeding or treatment-induced anemia. Further, the most recent transfusion episode must have occurred in the 28 days before study enrollment.25
Four patients had hemoglobin level of 85–93 g/l at baseline.
BMF grading was not available for 1 patient.
Ten patients had received more than one of the listed categories of prior MF treatment (JAK2 inhibitor, hydroxyurea (n=6); darbepoetin alfa, JAK2 inhibitor (n=2); hydroxyurea, darbepoetin alfa, JAK2 inhibitor (n=1); danazol, darbepoetin alfa, JAK2 inhibitor (n=1)).
Two patients received treatment with 2 different JAK2 inhibitors (one patient received pacritinib, then LY-2784544; the other patient received fedratinib, then ruxolitinib).