Background

Among therapies for immune thrombocytopenia (ITP) that achieve long unmaintained remissions, distant relapse rates have not been compared.

Specific Aims

To compare relapse rates following umaintained remissions exceeding 1 year in patients with ITP treated with steroids versus anti-Rh(D) with/without steroids versus rituximab with/without steroids.

Methods

Institutional Review Board approval was obtained. The charts of 52 consecutive patients with ITP followed in a hematology practice between 07/01/03 and 06/30/13 were reviewed. Remission was defined as a platelet count > 100,000/µL. Patients with the aforementioned treatment and remission characteristics were identified. Steroids were administered alone as dexamethasone 40 mg PO daily for 4 days. Anti-Rh(D) was administered as 75 mcg/kg IV with or without prednisone 60-85 mg PO daily tapered over 4 weeks or dexamethasone 40 mg PO daily for 4 days. Rituximab was administered as 375 mg/m2 IV weekly for 4 weeks or as a single dose with or without dexamethasone 40 mg PO daily for 4 days. Relapse was defined as a platelet count < 30,000/µL. Statistical calculations included ANOVA to compare demographics and chi-square contingency table analysis to compare distant relapse rates (http://www.physics.csbsju.edu/stats).

Results

There were 16 unmaintained remissions exceeding 1 year in 13 patients following treatment with steroids, anti-Rh(D) with/without steroids, or rituximab with/without steroids. Mean age on presentation, sex ratio, duration of ITP prior to therapy, and duration of follow-up after therapy were similar for the 3 groups (Table 1).

Table 1

Demographics

 Steroids (n=2) Anti-Rh(D) +/- steroids (n=8) Rituximab +/- steroids (n=6) P 
Age (y)
Mean (range) 		25
(18-33) 		47
(29-70) 		54
(28-75) 		0.44 
M:F ratio 1:1 1:1 1:1 1.0 
Duration of ITP prior to therapy (y)
Mean (range) 		0.85
(0.31-2) 		2.47
(0.01-10) 		4.75
(1.67-9) 		0.26 
Duration of follow-up after therapy (y)
Mean (range) 		2.17
(1.33-5.67) 		3.90
(1.73-8.63) 		3.89
(1.58-7.42) 		0.99 
Secondary ITP None HIV (n=1) None  
 Steroids (n=2) Anti-Rh(D) +/- steroids (n=8) Rituximab +/- steroids (n=6) P 
Age (y)
Mean (range) 		25
(18-33) 		47
(29-70) 		54
(28-75) 		0.44 
M:F ratio 1:1 1:1 1:1 1.0 
Duration of ITP prior to therapy (y)
Mean (range) 		0.85
(0.31-2) 		2.47
(0.01-10) 		4.75
(1.67-9) 		0.26 
Duration of follow-up after therapy (y)
Mean (range) 		2.17
(1.33-5.67) 		3.90
(1.73-8.63) 		3.89
(1.58-7.42) 		0.99 
Secondary ITP None HIV (n=1) None  
View Large

Distant relapse rates were 100%, 14.2%, and 66.7% for the steroid, anti-Rh(D) with/without steroid, and rituximab with/without steroid groups, respectively, P = 0.03 (Table 2).

Table 2

Distant relapse rates per treatment group

 Steroids (n=2) Anti-Rh(D) +/- steroids (n=8) Rituximab +/- steroids (n=6) P 
With distant relapse (n) 2 1 4 0.03 
Without distant relapse (n) 0 7 2  
 Steroids (n=2) Anti-Rh(D) +/- steroids (n=8) Rituximab +/- steroids (n=6) P 
With distant relapse (n) 2 1 4 0.03 
Without distant relapse (n) 0 7 2  
View Large
Conclusion

Among patients who achieve long unmaintained remissions of ITP with steroids, anti-Rh(D) with/without steroids, or rituximab with/without steroids, those treated with anti-Rh(D)-based therapy are the most likely to have extended remission.

Disclosures:

Off Label Use: Rituximab therapy of ITP.

Topics:
rituximab, steroids, inosine triphosphate, purpura, thrombocytopenic, idiopathic, disease remission, dexamethasone, follow-up, off-label use, prednisone, single-dose regimen
© 2013 by The American Society of Hematology
2013
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