Baseline characteristics
| Characteristic . | ET (n = 65) . | PV (n = 50) . | Total (N = 115) . |
|---|---|---|---|
| Sex | |||
| Female | 33 (50.8) | 24 (48.0) | 57 (49.6) |
| Male | 32 (49.2) | 26 (52.0) | 58 (50.4) |
| Age >60 y* | 38 (58.5) | 33 (66.0) | 71 (61.7) |
| Race | |||
| White | 54 (83.1) | 47 (94.0) | 101 (87.8) |
| Black or African American | 6 (9.2) | 2 (4.0) | 8 (7.0) |
| Asian | 2 (3.1) | 0 | 2 (1.7) |
| Not reported | 3 (4.6) | 1 (2.0) | 4 (3.5) |
| ECOG performance status (grade) | |||
| 0 | 44 (67.7) | 33 (66.0) | 77 (67.0) |
| 1 | 21 (32.3) | 16 (32.0) | 37 (32.2) |
| 2 | 0 (0.0) | 1 (2.0) | 1 (0.9) |
| Previous thrombosis | 21 (32.3) | 11 (22.0) | 32 (27.8) |
| Previous hemorrhage | 7 (10.8) | 6 (12) | 13 (11.2) |
| Splenomegaly | 12 (18.5) | 28 (56.0) | 40 (34.8) |
| Disease duration in months since diagnosis, median (range) | 37.3 (0.4-291) | 54.8 (0.5-394) | 42.3 (0.5-394) |
| HU resistant | 20 (31.3) | 17 (34.0) | 37 (32.5) |
| Not achieving platelet count <600 × 109/L† | 15 (75) | 4 (23.5) | 19 (51.4) |
| Progressive splenomegaly or hepatomegaly or new splenomegaly or hepatomegaly† | 2 (10) | 7 (44.2) | 9 (24.3) |
| Not achieving a HCT <45 without phlebotomy† | 2 (10) | 5 (29.4) | 7 (18.9) |
| Not achieving a WBC <10 × 109/L† | 5 (29.4) | 2 (10) | 7 (18.9) |
| Development of a major thrombotic episode† | 7 (35.0) | 2 (11.8) | 9 (24.3) |
| HU intolerant | 44 (68.8) | 33 (66.0) | 77 (67.5) |
| WBC < 2.5 × 109/L or hemoglobin <11 g/dL at any dose of HU | 11 (25.0) | 6 (18.2) | 17 (22.1) |
| Having a platelet count <100 × 109/L | 1 (2.3) | 3 (9.1) | 4 (5.2) |
| Presence of leg ulcers or other unacceptable HU-related nonhematological toxicities | 37 (84.1) | 25 (75.8 | 62 (80.5) |
| HU therapy discontinued | 26 (40.0) | 16 (32.0) | 42 (36.5) |
| HU therapy ongoing | 39 (60.0) | 34 (68.0) | 73 (63.5)‡ |
| WBC (×109/L), median (range) | 7.4 (2.4-55.7) | 11.1 (2.3-45.3) | 8.5 (2.3-55.7) |
| Platelets (×109/L), median (range) | 609 (124-1899) | 378 (15.2-1698) | 485 (15.2-1899) |
| HCT %, median (range) | 39.4 (40-53.7) | 44 (27.5-55.8) | 41 (40-55.8) |
| Driver mutations, n | |||
| JAK2V617F | 31 | 48 | — |
| CALR | 23 | — | — |
| MPL | 4 | 1 | — |
| Triple negative or unavailable | 8 | 2 | — |
| Characteristic . | ET (n = 65) . | PV (n = 50) . | Total (N = 115) . |
|---|---|---|---|
| Sex | |||
| Female | 33 (50.8) | 24 (48.0) | 57 (49.6) |
| Male | 32 (49.2) | 26 (52.0) | 58 (50.4) |
| Age >60 y* | 38 (58.5) | 33 (66.0) | 71 (61.7) |
| Race | |||
| White | 54 (83.1) | 47 (94.0) | 101 (87.8) |
| Black or African American | 6 (9.2) | 2 (4.0) | 8 (7.0) |
| Asian | 2 (3.1) | 0 | 2 (1.7) |
| Not reported | 3 (4.6) | 1 (2.0) | 4 (3.5) |
| ECOG performance status (grade) | |||
| 0 | 44 (67.7) | 33 (66.0) | 77 (67.0) |
| 1 | 21 (32.3) | 16 (32.0) | 37 (32.2) |
| 2 | 0 (0.0) | 1 (2.0) | 1 (0.9) |
| Previous thrombosis | 21 (32.3) | 11 (22.0) | 32 (27.8) |
| Previous hemorrhage | 7 (10.8) | 6 (12) | 13 (11.2) |
| Splenomegaly | 12 (18.5) | 28 (56.0) | 40 (34.8) |
| Disease duration in months since diagnosis, median (range) | 37.3 (0.4-291) | 54.8 (0.5-394) | 42.3 (0.5-394) |
| HU resistant | 20 (31.3) | 17 (34.0) | 37 (32.5) |
| Not achieving platelet count <600 × 109/L† | 15 (75) | 4 (23.5) | 19 (51.4) |
| Progressive splenomegaly or hepatomegaly or new splenomegaly or hepatomegaly† | 2 (10) | 7 (44.2) | 9 (24.3) |
| Not achieving a HCT <45 without phlebotomy† | 2 (10) | 5 (29.4) | 7 (18.9) |
| Not achieving a WBC <10 × 109/L† | 5 (29.4) | 2 (10) | 7 (18.9) |
| Development of a major thrombotic episode† | 7 (35.0) | 2 (11.8) | 9 (24.3) |
| HU intolerant | 44 (68.8) | 33 (66.0) | 77 (67.5) |
| WBC < 2.5 × 109/L or hemoglobin <11 g/dL at any dose of HU | 11 (25.0) | 6 (18.2) | 17 (22.1) |
| Having a platelet count <100 × 109/L | 1 (2.3) | 3 (9.1) | 4 (5.2) |
| Presence of leg ulcers or other unacceptable HU-related nonhematological toxicities | 37 (84.1) | 25 (75.8 | 62 (80.5) |
| HU therapy discontinued | 26 (40.0) | 16 (32.0) | 42 (36.5) |
| HU therapy ongoing | 39 (60.0) | 34 (68.0) | 73 (63.5)‡ |
| WBC (×109/L), median (range) | 7.4 (2.4-55.7) | 11.1 (2.3-45.3) | 8.5 (2.3-55.7) |
| Platelets (×109/L), median (range) | 609 (124-1899) | 378 (15.2-1698) | 485 (15.2-1899) |
| HCT %, median (range) | 39.4 (40-53.7) | 44 (27.5-55.8) | 41 (40-55.8) |
| Driver mutations, n | |||
| JAK2V617F | 31 | 48 | — |
| CALR | 23 | — | — |
| MPL | 4 | 1 | — |
| Triple negative or unavailable | 8 | 2 | — |