Moxetumomab pasudotox in heavily pre-treated patients with relapsed/refractory hairy cell leukemia (HCL): long-term follow-up from the pivotal trial

Table 2 Moxetumomab pasudotox was associated with a high response rate and MRD negativity among complete responders

Parameter	Value (N = 80), ITT population
Parameter	Blinded independent central review	Investigator assessment
Durable CR [primary endpoint], n (%)	29 (36)	39 (49)
95% CI^a	26, 48	37, 60
CR with HR ≥ 360 days, n (%)	26 (33)	36 (45)
95% CI^a	22, 44	34, 57
Best overall response
CR, n (%)	33 (41)	42 (53)
95% CI^a	30, 53	41, 64
CR and MRD–, n (%)^b	27 (34)	26 (33)
95% CI^a	24, 45	22, 44
CR and MRD + , n (%)^b	6 (8)	6 (8)
95% CI^a	3, 16	3, 16
PR, n (%)	27 (34)	21 (26)
Objective response rate [CR or PR], n (%)	60 (75)	63 (79)
95% CI^a	64, 84	68, 87
Median duration of response, months (range)	66.7 (0+ to 66.7)	42.1 (0.0 + to 69.0)
Median duration of CR, months (range)	62.8 (0.1+ to 62.8)	56.6 (0.0 + to 69.0)

CR was defined as clearing of the bone marrow of hairy cells (determined by routine hematoxylin and eosin stain), radiologic resolution of pre-existing lymphadenopathy and/or organomegaly, and HR. PR was defined as ≥ 50% decrease or normalization (< 500/mm³) in peripheral blood lymphocyte count, reduction of pre-existing lymphadenopathy and/or organomegaly, and HR or 50% improvement in neutrophils, platelets, and hemoglobin over baseline (without transfusions or growth factors for at least 4 weeks)
CI confidence interval, CR complete response, HR hematologic remission, IHC immunohistochemistry, ITT intent-to-treat, MRD minimal residual disease, PR partial response
^aTwo-sided CI was calculated using the exact probability method based on the binomial distribution. ^bDetermined by IHC

ISSN: 1756-8722