Comparison of Hospital Length of Stay and Supportive Care Utilization Between Patients Treated with CPX-351 and 7+3 for Therapy-Related Acute Myeloid Leukemia or Acute Myeloid Leukemia with Myelodysplasia-Related Changes

Figures & data

Figure 1 Patient attrition.

Abbreviations: AML, acute myeloid leukemia; t-AML, therapy-related acute myeloid leukemia; AML-MRC, acute myeloid leukemia with myelodysplasia-related changes; MDS, myelodysplastic syndrome; MPN, myeloproliferative neoplasm.

Figure 2 Study period.

Table 1 Patient and Visit Characteristics

	CPX-351 (N=195)		7+3 (CPX-351 Eligible) (N=160)		Nominal p-value
	N	%	N	%
Age, years
Median (25th–75th percentiles)	68	(61–71)	61	(52.5–81)	<0.001
Age group, years
18–44	5	2.6	23	14.4	<0.001
45–64	66	33.8	76	47.5
65–74	99	50.8	44	27.5
≥75	25	12.8	17	10.6
Sex
Female	73	37.4	72	45.0	0.149
Male	122	62.6	88	55.0
Race
Black	13	6.7	11	6.9	0.792
White	141	72.3	120	75.0
Other	41	21.0	29	18.1
Ethnicity
Hispanic	19	9.7	18	11.3	0.460
Non-Hispanic	133	68.2	115	71.9
Unknown	43	22.1	27	16.9
Primary payer
Commercial	55	28.2	46	28.8	0.012
Medicaid	18	9.2	27	16.9
Medicare	115	59.0	73	45.6
Other	7	3.6	14	8.8
Admission type
Elective	73	37.4	55	34.4	0.203
Emergency	49	25.1	40	25.0
Other, unknown	11	5.6	3	1.9
Urgent	62	31.8	62	38.8

Table 2 Hospital Characteristics

	CPX-351 (N=195)		7+3 (CPX-351 Eligible) (N=160)		Nominal p-value
	N	%	N	%
Number of hospitals	52	–	71	–
Populations served
Rural	5	2.6	10	6.3	0.086
Urban	190	97.4	150	93.8
Teaching status
Non-teaching	24	12.3	47	29.4	<0.001
Teaching	171	87.7	113	70.6
US geographic divisions
East North Central	20	10.3	28	17.5	<0.001
East South Central	5	2.6	12	7.5
Middle Atlantic	52	26.7	22	13.8
Mountain	2	1.0	4	2.5
New England	2	1.0	1	0.6
Pacific	7	3.6	11	6.9
South Atlantic	90	46.2	37	23.1
West North Central	7	3.6	9	5.6
West South Central	10	5.1	36	22.5
Bed size
<100	0	0	0	0	0.054
100–199	3	1.5	9	5.6
200–299	5	2.6	9	5.6
300–499	30	15.4	28	17.5
≥500	157	80.5	114	71.3

Table 3 Clinical Characteristics

	CPX-351 (N=195)		7+3 (CPX-351 Eligible) (N=160)		Nominal p-value
	N	%	N	%
Cancer characteristics
Prior MDS	39	20.0	64	40.0	<0.001
Type of AML^a
Newly diagnosed t-AML	64	32.8	144	90.0	<0.001
AML-MRC	40	20.5	68	42.5	<0.001
Undetermined	127	65.1	0	0	<0.001
Treatments within 12-month pre-index period
HMA	25	12.8	22	13.8	0.875
Anthracycline	5	2.6	16	10.1	0.005
Charlson-Deyo comorbidities
Charlson Comorbidity Index
0	0	0	0	0	0.075
1–3	146	74.9	106	66.3
≥4	49	25.1	54	33.8
Charlson chronic comorbidities
Myocardial infarction	11	5.6	6	3.8	0.406
Congestive heart failure	24	12.3	14	8.8	0.281
Peripheral vascular disease	13	6.7	11	6.9	0.938
Cerebrovascular disease	1	0.5	3	1.9	0.226
Dementia	1	0.5	1	0.6	0.888
Chronic pulmonary disease	36	18.5	32	20.0	0.714
Rheumatic disease	3	1.5	2	1.3	0.819
Peptic ulcer disease	1	0.5	0	0.0	0.364
Mild liver disease	9	4.6	7	4.4	0.914
Diabetes without chronic complication	28	14.4	38	23.8	0.024
Diabetes with chronic complication	6	3.1	17	10.6	0.004
Hemiplegia or paraplegia	1	0.5	3	1.9	0.226
Moderate or severe renal disease	16	8.2	17	10.6	0.435
Any malignancy, including lymphoma and leukemia, except malignant neoplasm of skin	195	100.0	160	100.0
Moderate or severe liver disease	0	0	1	0.6	0.269
Metastatic solid tumor	2	1.0	6	3.8	0.085
AIDS/HIV	7	3.6	9	5.6	0.358

Notes: ^aSince patients could have evidence of both newly diagnosed t-AML and AML-MRC, the percentages in each treatment cohort exceed 100%. CPX-351 patients who could not be identified with t-AML and AML-MRC due to limitations of the data source were grouped as undetermined; all CPX-351 patients were assumed to have newly diagnosed t-AML or AML-MRC in accordance with its FDA-approved treatment indications.

Abbreviations: MDS, myelodysplastic syndrome; AML, acute myeloid leukemia; t-AML, therapy-related acute myeloid leukemia; AML-MRC, acute myeloid leukemia with myelodysplasia-related changes; HMA, hypomethylating agent; AIDS/HIV, acquired immunodeficiency syndrome/human immunodeficiency virus.

Table 4 Unadjusted LOS and Supportive Care Utilization Before Annualization

	CPX-351 (N=195)	7+3 (CPX-351 Eligible) (N=160)	p-value
Length of follow-up, days			0.648
Mean (SD)	171.7 (133.0)	169.8 (138.9)
Median (25th–75th percentiles)	136.0 (68–232)	126.0 (54.5–241.5)
Total inpatient LOS, days			0.170
Mean (SD)	54.0 (29.6)	60.7 (32.9)
Median (25th–75th percentiles)	49.0 (35–69)	51.5 (37–73)
Total number of administrations of platelets			0.325
Mean (SD)	3.0 (3.6)	2.8 (3.1)
Median (25th–75th percentiles)	2.0 (1–3)	2.0 (1–3)
Total number of administrations of RBC			0.224
Mean (SD)	3.0 (3)	2.6 (2.5)
Median (25th–75th percentiles)	2.0 (1–3)	2.0 (1–3)
Total number of days on anti-infectives			0.304
Mean (SD)	6.6 (3.6)	6.3 (3.8)
Median (25th–75th percentiles)	6.0 (4–9)	5.5 (4–7.5)
Total number of days on WBC-CSF			0.360
Mean (SD)	1.4 (0.8)	1.5 (0.8)
Median (25th–75th percentiles)	1.0 (1–2)	1.0 (1–2)

Abbreviations: LOS, length of stay; SD, standard deviation; RBC, red blood cells; WBC-CSF, white blood cell colony-stimulating factor.

Table 5 Regression-Adjusted LOS and Supportive Care Utilization

	CPX-351 (N=195)	7+3 (CPX-351 Eligible) (N=160)
	Mean Estimates (95% CI)^a	Mean Estimates (95% CI)^a	p-value^a
Overall annualized inpatient LOS, days^b	183.7 (180.1–187.1)	197.1 (193.3–200.8)	<0.001
Annualized inpatient LOS in patients with newly diagnosed t-AML, days^b	168.9 (164.5–172.8)	192.5 (187.6–197.0)	<0.001
Annualized inpatient LOS in patients without evidence of newly diagnosed t-AML, days^b	190.4 (185.5–194.8)	181.3 (176.7–185.5)	0.025
Annualized number of administrations of platelets^c	4.8 (4.6–5.1)	4.5 (4.3–4.8)	0.368
Annualized number of administrations of RBC^d	5.0 (4.8–5.3)	4.9 (4.6–5.2)	0.512
Annualized number of days on anti-infectives^e	22.4 (21.7–23.3)	22.9 (22.1–23.7)	0.408
Annualized number of days on WBC-CSF^f	2.0 (2.0–2.1)	3.0 (2.9–3.1)	0.053

Notes: ^aAll p-values nominal except for LOS. ^bThe key independent variables were treatment (CPX-351 vs 7+3), t-AML interaction term between t-AML, and treatment. The following covariates were included in the final regression model after backward selection: age, gender, race, ethnicity, primary payer, hospital census region, hospital bed size, type of admission (emergent, urgent, or elective), Charlson-Deyo Comorbidity Index, AML-MRC, prior HMA use, and number of days from the start of follow-up to the end of the study period. ^cThe key independent variable was treatment (CPX-351 vs 7+3). Covariates included: race, ethnicity, hospital census region, hospital bed size, type of admission, AML-MRC, and prior HMA use. ^dThe key independent variable was treatment (CPX-351 vs 7+3). Covariates included: race, ethnicity, hospital census region, hospital bed size, type of admission, AML-MRC, and t-AML. ^eThe key independent variable was treatment (CPX-351 vs 7+3). Covariates included: race, ethnicity, primary payer, hospital census region, hospital bed size, type of admission, Charlson-Deyo Comorbidity Index, prior HMA use, and prior anthracycline use. ^fThe key independent variable was treatment (CPX-351 vs 7+3). Covariates included: primary payer, hospital census region, teaching hospital, number of days from the start of follow-up to the end of the study period.

Abbreviations: LOS, length of stay; CI, confidence interval; t-AML, therapy-related acute myeloid leukemia; RBC, red blood cells; WBC-CSF, white blood cell colony-stimulating factor; AML-MRC, acute myeloid leukemia with myelodysplasia-related changes; HMA, hypomethylating agent.