Table 1 Comparison of clinical characteristics at time of treatment initiation and outcomes for 183 JAK2 inhibitor-naive patients with myelofibrosis receiving JAK2 inhibitors in the context of clinical trials.
Variables | All patients N = 183 | Ruxolitinib N = 50 (27%) (P value vs others) | Fedratinib N = 23 (13%) (P value vs others) | Momelotinib N = 79 (43%) (P value vs others) | BMS-911543 JAK2 inhibitor N = 31(17%) (P value vs others) |
|---|---|---|---|---|---|
Age in years, median (range) | 65 (34–89) | 62 (39–78) (0.02) | 64 (47–83) (0.93) | 67 (34–89) (<0.01) | 64 (34–78) (0.21) |
Male, n (%) | 106 (58) | 37 (74) (0.01) | 13 (57) (0.88) | 43 (54) (0.40) | 13 (42) (0.04) |
MF type, n (%) | |||||
- Post-ET MF | 27 (15) | 7 (14) | 3 (13) | 12 (15) | 5 (16) |
- Post-PV MF | 47 (26) | 17 (34) | 6 (26) | 16 (20) | 8 (26) |
- PMF | 109 (60) | 26 (52) (0.29) | 14 (61) (0.97) | 51 (65) (0.33) | 18 (58) (0.97) |
Driver mutation, n (%) | n = 175 | n = 46 | n = 23 | n = 79 | n = 27 |
- JAK2 | 140 (80) | 42 (84) | 21 (91) | 56 (71) | 21 (78) |
- CALR | 20 (11) | 1 (2) | 2 (9) | 13 (16) | 4 (15) |
- MPL | 8 (5) | 1 (2) | 0 | 6 (8) | 1 (4) |
- Triple negative | 7 (4) | 2 (4) | 0 | 4 (5) | 1 (4) |
Type 1/like CALR vs others | (0.04) | (0.86) | (0.09) | (0.79) | |
Mutations, n (%) | |||||
- ASXL1 | 58/124 (47) | 16/30 (53) (0.41) | 6/10 (60) (0.38) | 30/72 (42) (0.18) | 6/12 (50) (0.81) |
- IDH1/2 | 2/74 (3) | 0/25 (0) (0.20) | 0/7 (0) (0.53) | 2/38 (5) (0.10) | 0/4 (0) (0.63) |
- SRSF2 | 16/84 (19) | 2/15 (13) (0.52) | 1/6 (17) (0.88) | 13/59 (22) (0.27) | 0/4 (0) (0.19) |
- U2AF1 | 3/47 (6) | 0/7 (0) (0.32) | 2/4 (50) (0.01) | 1/36 (3) (0.10) | 0 - |
Splenomegaly, n (%) | 166 (91) | 47/49 (96) (0.71) | 23 (100) (0.11) | 72/77 (94) (0.45) | 27/29 (93) (0.64) |
Transfusion-dependent, n (%) | 66 (36) | 10 (20) (<0.01) | 10 (43) (0.43) | 37 (47) (0.01) | 9 (29) (0.37) |
Constitutional symptoms, n (%) | 136 (74) | 42 (84) (0.06) | 17 (74) (0.96) | 46 (58) (<0.01) | 31 (100) (<0.01) |
Prior treatment, n (%) | 144 (79) | 45 (90) (0.02) | 19 (83) (0.62) | 57 (72) (0.06) | 23 (74) (0.51) |
- Hydroxyurea | 101 (55) | 34 (68) | 14 (61) | 37 (47) | 16 (52) |
- ESA | 36 (20) | 14 (28) | 5 (22) | 17 (22) | 0 |
- Interferon | 15 (8) | 9 (18) | 1 (4) | 4 (5) | 1 (3) |
- Thalidomide | 27 (15) | 14 (28) | 4 (17) | 7 (9) | 2 (6) |
- Lenalidomide | 17 (9) | 10 (20) | 1 (4) | 4 (5) | 2 (6) |
- Pomalidomide | 24 (13) | 5 (10) | 1(4) | 15 (19) | 3 (10) |
Diagnosis to start of therapy, months, median (range) | 27 (0.1–419) | 33 (0.2–419) (0.39) | 16 (1.4–280) (0.15) | 25 (0.1–275) (0.65) | 40 (0.3–188) (0.50) |
Hemoglobin, g/dl, median (range) | 9.9 (6.4–15.3) | 10.6 (7.6–15.3) (0.01) | 9.5 (7.9–14.7) (0.54) | 9.6 (6.7–14) (<0.01) | 9.9 (6.4–14.6) (0.95) |
Leukocyte count × 109/L, median (range) | 13.7 (1.5–232) | 15.6 (2.2–136) (0.83) | 25.5 (4–219) (0.02) | 10.9 (1.5–232) (0.07) | 12 (3.2–129.5) (0.63) |
Platelet count × 109/L, median (range) | 204 (51–1061) | 222 (75–774) (0.37) | 236 (82–1061) (0.02) | 169 (51–738) (0.07) | 204 (56–636) (0.32) |
Circulating blasts %, median (range) | 1(0–14) | 1 (0–11) (0.48) | 2 (0–9) (0.30) | 1 (0–14) (0.80) | 1 (0–5) (0.10) |
Karyotype, n (%) | |||||
- Abnormal karyotype | 97 (53) | 28 (54) (0.62) | 11 (48) (0.59) | 41 (52) (0.79) | 17 (55) (0.82) |
- Unfavorable karyotype | 51 (28) | 13 (26 (0.59) | 8 (35) (0.52) | 23 (29) (0.97) | 9 (29) (0.99) |
DIPSS plus risk, n (%) | |||||
- Intermediate-1 | 28 (15) | 17 (34) | 3 (13) | 1 (1) | 7(23) |
- Intermediate-2 | 84 (46) | 27 (54) | 14 (61) | 29 (37) | 14 (45) |
- High | 71 (39) | 6 (12) (<0.01) | 6 (26) (0.29) | 49 (62) (<0.01) | 10 (32) (0.45) |
Spleen response, n (%) | 83/166 (50) | 15/47 (32) (<0.01) | 19/23 (83) (<0.01) | 33/70 (47) (0.53) | 16/26 (62) (0.19) |
Anemia response in transfusion-dependent patients, n (%) | 27/66 (41) | 3/10 (30) (0.44) | 1/10 (10) (0.02) | 19/37 (51) (0.04) | 4/9 (44) (0.82) |
Symptom response, n (%) | 8/136 (60) | 24/42 (57) (0.54) | 11/17 (65) (0.74) | 22/46 (48) (<0.01) | 26/31 (84) (<0.01) |
Hematological toxicity, n (%) | 138 (75) | 38 (76) (0.91) | 20 (87) (0.14) | 58 (73) (0.59) | 22 (71) (0.53) |
Non-Hematological toxicity, n (%) | 152 (83) | 38 (76) (0.13) | 21 (91) (0.23) | 75 (95) (<0.01) | 18 (58) (<0.01) |
Discontinuation of JAK2 inhibitor, n (%) | 177 (97) | 50 (100) | 23 (100) | 74 (94) | 31 (100) |
Time on JAK2 inhibitor in months (median, range) | n = 177 | n = 50 | n = 23 | n = 74 | n = 31 |
17 (0.1–125) | 10 (0.8–68) (<0.01) | 21 (1.8–55) (0.78) | 21 (0.1–125) (<0.01) | 16 (0.3–47) (0.56) | |
Leukemic transformation n (%) | 27 (15) | 9 (18) (0.46) | 1 (4) (0.1) | 13 (16) (0.57) | 4 (13) (0.75) |
Allogeneic transplant, n (%) | 22 (12) | 6 (12) (1.0) | 4 (17) (0.42) | 7 (9) (0.25) | 5 (16) (0.46) |
