Infections in secondary immunodeficiency patients treated with Privigen^® or Hizentra^®: a retrospective US administrative claims study in patients with hematological malignancies

Figures & data

Table 1. Baseline patient characteristics.

Characteristics	IgRT (N = 277)	Non-IgRT (N = 1019)	p value
Mean age, years	57.2	56.6	.3944
Sex, n (%)
Female	120 (43.3)	453 (44.5)	.7361
Underlying malignancy, n (%)^a
CLL	111 (40.1)	358 (35.1)	.1293
MM	40 (14.4)	138 (13.5)	.7003
NHL	170 (61.4)	643 (63.1)	.5976
Comorbid conditions of interest, n (%)^a
Neutropenia	99 (35.7)	276 (27.1)	.0049
Sinusitis	113 (40.8)	274 (26.9)	<.0001
Bronchitis	70 (25.3)	185 (18.2)	.0083
Diabetes	58 (20.9)	195 (19.1)	.5022
Therapies of interest, n (%)
Any antibiotic	265 (95.7)	887 (87.0)	<.0001
IV antibiotics	107 (38.6)	250 (24.5)	<.0001
Cancer treatments	155 (56.0)	468 (45.9)	.0031
Chemotherapy	92 (33.2)	296 (29.0)	.1796
Biologics (monoclonal antibodies)	99 (35.7)	232 (22.8)	<.0001
Small molecule targeted therapies	44 (15.9)	107 (10.5)	.0133
Radiation	20 (7.2)	84 (8.2)	.5783
Immunosuppressive drugs	40 (14.4)	108 (10.6)	.0746
Physician office visits, mean (SD)	34.5 (26.0)	27.6 (22.9)	<.0001
Hospitalization, n (%)	150 (54.2)	495 (48.6)	.0999
Hospitalization with BI diagnosis, n (%)	101 (36.5)	290 (28.5)	.0101
IgG levels tested, n (%)	239 (86.3)	618 (60.6)	<.0001

BI: bacterial infection; CLL: chronic lymphocytic leukemia; IgG: immunoglobulin G; IgRT: immunoglobulin replacement therapy; IV: intravenous; MM: multiple myeloma; NHL: non-Hodgkin lymphoma; SD: standard deviation.

a Patients could have more than one underlying malignancy/comorbid condition of interest and are included in each relevant subgroup.

Table 2. Hematologic malignancy treatments by cancer subtype and by IgRT group during the baseline period.

	CLL (n = 469)			NHL (n = 813)			MM (n = 178)
Characteristics	IgRT (n = 111)	Non-IgRT (n = 358)	p value	IgRT (n = 170)	Non-IgRT (n = 643)	p value	IgRT (n = 40)	Non-IgRT (n = 138)	p value
Cancer treatments, n (%)	59 (53.2)	116 (32.4)	<.0001	102 (60.0)	329 (51.2)	.0401	28 (70.0)	87 (63.0)	.4179
Chemotherapy	38 (34.2)	80 (22.3)	.0117	60 (35.3)	219 (34.1)	.7629	14 (35.0)	38 (27.5)	.3607
Biologics (mABs)	44 (39.6)	80 (22.3)	.0003	73 (42.9)	185 (28.8)	.0004	4 (10.0)	8 (5.8)	.4714
Alemtuzumab	0 (0.0)	1 (0.3)	1.0000	0 (0.0)	1 (0.2)	1.0000	0 (0.0)	0 (0.0)	N/A
Rituximab	38 (34.2)	76 (21.2)	.0053	70 (41.2)	183 (28.5)	.0014	3 (7.5)	3 (2.2)	.1280
Rituximab-hyaluronidase	0 (0.0)	0 (0.0)	N/A	0 (0.0)	0 (0.0)	N/A	0 (0.0)	0 (0.0)	N/A
Obinutuzumab	1 (0.9)	3 (0.8)	1.0000	2 (1.2)	0 (0.0)	.0435	0 (0.0)	0 (0.0)	N/A
Ofatumumab	6 (5.4)	1 (0.3)	.0009	1 (0.6)	0 (0.0)	.2091	0 (0.0)	0 (0.0)	N/A
Small molecule targeted  therapies (including  proteasome inhibitors)^a	13 (11.7)	15 (4.2)	.0035	19 (11.2)	37 (5.8)	.0130	21 (52.5)	69 (50.0)	.7807
Cancer related hormones	1 (0.9)	1 (0.3)	.4177	7 (4.1)	19 (3.0)	.4435	1 (2.5)	3 (2.2)	1.0000
Immunotherapy	0 (0.0)	0 (0.0)	N/A	1 (0.6)	0 (0.0)	.2091	0 (0.0)	0 (0.0)	N/A
Radiochemotherapy	0 (0.0)	1 (0.3)	1.0000	3 (1.8)	2 (0.3)	.0646	0 (0.0)	0 (0.0)	N/A
Radiation	7 (6.3)	14 (3.9)	.2863	16 (9.4)	62 (9.6)	.9277	2 (5.0)	17 (12.3)	.1869
Immunosuppressive drugs, n (%)	10 (9.0)	27 (7.5)	.6164	26 (15.3)	91 (14.2)	.7061	10 (25.0)	7 (5.1)	.0002

CLL: chronic lymphocytic leukemia; IgRT: immunoglobulin replacement therapy; mABs: monoclonal antibodies; MM: multiple myeloma; NHL: non-Hodgkin lymphoma.

IgRT group consists of IgPro10 and IgPro20 patients.

a A full list of ‘small molecule targeted therapies’ can be found in Supplementary Table 4.

Figure 1. Percentage of patients with bacterial infections during the baseline period, in IgRT or non-IgRT users. *All p<.0001 for IgRT versus non-IgRT users; except for severe BI (p=.0011). BI: bacterial infections; IgRT: immunoglobulin replacement therapy.

Figure 2. Mean number of bacterial infections per patient, in the 12-month baseline and follow-up periods (observed and predicted) for the overall cohort and cancer-specific subtypes. Follow-up period predicted values were estimated using a GLM approach with a Poisson distribution and log-link transformation. BI: bacterial infections; CLL: chronic lymphocytic leukemia; GLM: generalized linear regression model; IgRT: immunoglobulin replacement therapy; MM: multiple myeloma; NHL: non-Hodgkin lymphoma.

Figure 3. Percentage of patients with ≥1 severe bacterial infection during the baseline and follow-up periods, in IgRT or non-IgRT users. BI: bacterial infection; CLL: chronic lymphocytic leukemia; IgRT: immunoglobulin replacement therapy; MM: multiple myeloma; NHL: non-Hodgkin lymphoma.

Figure 4. Mean number of severe bacterial infections per patient, in the 12-month baseline and follow-up periods (observed and predicted) for the overall cohort and cancer-specific subtypes. Follow-up period predicted values were estimated using a GLM approach with a Poisson distribution and log-link transformation. The impact of IgRT on severe BI was statistically significant during the follow-up period in the overall cohort and for the NHL and CLL subtypes, but not for the MM subtype, based on evidence from the corresponding GLM models. BI: bacterial infections; CLL: chronic lymphocytic leukemia; GLM: generalized linear regression model; IgRT: immunoglobulin replacement therapy; MM: multiple myeloma; NHL: non-Hodgkin lymphoma.

Data availability statement

The data that support the findings of this study are available from the corresponding author, RM, upon reasonable request.