Table 1.
Baseline characteristics and outcomes for younger (<65 years) vs. older (≥65 years) patients
| Parameter | <65 years (n = 223) | ≥65 years (n = 63) |
|---|---|---|
| Median (range) age, years | 48 (18–64) | 70 (65–91) |
| Male, n (%) | 117 (53) | 33 (52) |
| Race, n (%) | ||
| White | 132 (59) | 54 (86) |
| Asian | 58 (26) | 6 (10) |
| Black | 15 (7) | 1 (2) |
| Othera | 18 (8) | 2 (3) |
| ECOG performance status, n (%) | ||
| 0 | 180 (81) | 39 (62) |
| 1 | 41 (18) | 24 (38) |
| 2 | 1 (<1) | 0 |
| Missing | 1 (<1) | 0 |
| Median (range) number of ongoing medications at baseline | 2 (1–10) | 4 (1–12) |
| Prior IFNα therapy, n (%) | 71 (32) | 29 (46) |
| Prior imatinib therapy, n (%) | ||
| Intolerant | 63 (28) | 27 (43) |
| Resistant | 160 (72) | 36 (57) |
| Median (range) duration of CML diagnosis, years | 3·3 (0·2–15·1) | 5·4 (0·1–13·7) |
| Median (range) duration of bosutinib treatment, months | 28·4 (0·2–83·4) | 13·9 (0·3–71·9) |
| Median (range) follow‐up, months | 46·8 (0·6–83·4) | 35·1 (0·9–74·0) |
| Baseline medical history events, n (%) | 188 (84) | 61 (97) |
| Events occurring in ≥15% of patients (either age group), n (%) | ||
| Hypertension | 39 (18) | 27 (43) |
| Anaemia | 40 (18) | 19 (30) |
| Obesity | 41 (18) | 12 (19) |
| Fatigue | 31 (14) | 13 (21) |
| Thrombocytopenia | 35 (16) | 9 (14) |
| Depression | 15 (7) | 12 (19) |
| Periorbital oedema | 10 (5) | 10 (16) |
| Cytogenetic response,b n (%) [95% CI] | ||
| Evaluable patients | 203 | 61 |
| MCyR | 123 (61) [54–67] | 33 (54) [41–67] |
| CCyR | 101 (50) [43–57] | 29 (48) [35–61] |
| Probability of maintaining MCyR at 4 years, % (95% CI)c | 75 (66–82) | 72 (52–85) |
| TEAEs (any grade) with ≥8% difference between age groups, n (%) | ||
| Diarrhoea | 187 (84) | 58 (92) |
| Vomiting | 78 (35) | 29 (46) |
| Fatigue | 50 (22) | 24 (38) |
| Decreased appetite | 24 (11) | 17 (27) |
| Weight decreased | 18 (8) | 16 (25) |
| Asthenia | 26 (12) | 15 (24) |
| Dyspnea | 18 (8) | 15 (24) |
| Pleural effusion | 9 (4) | 14 (22) |
| Peripheral oedema | 17 (8) | 14 (22) |
| Back pain | 26 (12) | 13 (21) |
| Abdominal pain | 63 (28) | 12 (19) |
| Blood creatinine increased | 11 (5) | 11 (18) |
| ALT increased | 55 (25) | 9 (14) |
| AST increased | 47 (21) | 8 (13) |
| Chills | 10 (5) | 8 (13) |
| Neutropenia | 40 (18) | 6 (10) |
| Contusion | 2 (1) | 6 (10) |
| Oropharyngeal pain | 29 (13) | 3 (5) |
| Dose interruption due to a TEAE, n (%) | 155 (70) | 50 (79) |
| Dose reduction due to a TEAE, n (%) | 103 (46) | 36 (57) |
| Discontinuation due to an AE, n (%) | 44 (20) | 20 (32) |
| Death within 30 days of last dose due to an AE, n (%) | 6 (3) | 1 (2) |
| Transformation to AP/BP CML at 4 years,d n (%) | 9 (4) | 2 (3) |
| PD/death at 4 years,e% [95% CI] | 18 (14–24) | 21 (13–34) |
| OS at 2 years,c , f% [95% CI] | 93 (88–95) | 87 (75–93) |
AE, adverse event; ALT, alanine aminotransferase; AP, accelerated phase; AST, aspartate aminotransferase; BP, blast phase; CCyR, complete cytogenetic response; 95% CI, 95% confidence interval; CML, chronic myeloid leukaemia; ECOG, Eastern Cooperative Oncology Group; FISH, fluorescence in situ hybridization; MCyR, major cytogenetic response; IFNα, interferon‐α; OS, overall survival; PCyR, partial cytogenetic response; PD, progressive disease; Ph+, Philadelphia chromosome–positive; TEAE, treatment‐emergent adverse event.
Other races: American Indian or Alaska Native (n = 1), Hispanic (n = 15), Mestizo (n = 2), mixed race (n = 1), North African (n = 1).
Evaluable patients must have had an adequate baseline cytogenetic assessment with ≥20 metaphases or ≥1 Ph+ metaphase from bone marrow cytogenetics. Cytogenetic response (Baccarani et al, 2006) was determined using standard cytogenetics (G‐band karyotype) with ≥20 metaphases counted for postbaseline assessments; if <20 metaphases were available postbaseline, FISH analysis of bone marrow aspirate or peripheral blood with ≥200 cells for the presence of BCR‐ABL1 fusion gene was used. MCyR included PCyR (1%–35% Ph+ metaphases) and CCyR (0% Ph+ metaphases; <1% if using FISH). Cytogenetic response could be newly achieved during the study or maintained from baseline for ≥4 weeks.
Based on Kaplan–Meier estimates.
Based on cumulative incidence adjusting for competing risk of treatment discontinuation without transformation.
Based on cumulative incidence adjusting for competing risk of treatment discontinuation without PD or death; PD defined as transformation to AP or BP CML, increasing white blood cell count (doubling over ≥1 month with second count >20 × 109/L and confirmed ≥1 week later), or loss of confirmed complete haematologic response or unconfirmed MCyR.
Patients were only followed for OS for 2 years after treatment discontinuation (per protocol).