A randomized, double-blind, placebo-controlled phase 2 study evaluating the efficacy and safety of romiplostim treatment of patients with low or intermediate-1 risk myelodysplastic syndrome receiving lenalidomide

Table 2 Clinical outcomes by baseline platelet count and deletion(5q) cytogenetic abnormality status

Efficacy variables	Placebo		Romiplostim
			500 μg		750 μg
	N^*,†	n (%)	N^*	n (%)	N	n (%)
Clinically significant thrombocytopenic event^‡
Overall	12	8 (67)	14	4 (29)	13	8 (62)
Baseline platelets <50 × 10⁹/L	5	5 (100)	5	2 (40)	5	5 (100)
Baseline platelets ≥50 × 10⁹/L	6	3 (50)	8	2 (25)	8	3 (38)
Del(5q) detected at baseline	1	0 (0)	3	0 (0)	2	0 (0)
Lenalidomide dose reduction or delay^§
Overall	12	6 (50)	14	5 (36)	13	2 (15)
Baseline platelets <50 × 10⁹/L	5	3 (60)	5	1 (20)	5	0 (0)
Baseline platelets ≥50 × 10⁹/L	6	3 (50)	8	4 (50)	8	2 (25)
Del(5q) detected at baseline	1	1 (100)	3	0 (0)	2	0 (0)
Achieved MDS treatment response^¶
Overall	12	1 (8)	14	2 (14)	13	3 (23)
Patients with baseline platelets <50 × 10⁹/L	5	0 (0)	5	1 (20)	5	0 (0)
Patients with baseline platelets ≥50 × 10⁹/L	6	1 (17)	8	1 (13)	8	3 (38)
Del(5q) detected at baseline	1	0 (0)	3	1 (33)	2	1 (50)
Achieved erythroid response^∥
Overall	6	2 (33)	7	2 (29)	8	2 (25)
Baseline platelets <50 × 10⁹/L	3	1 (33)	2	0 (0)	4	1 (25)
Baseline platelets ≥50 × 10⁹/L	3	1 (33)	5	2 (40)	4	1 (25)

^* Includes 1 patient who was found to be ineligible for the study after randomization and did not receive treatment.
^† Includes two patients who erroneously received one dose of romiplostim (500 μg and 750 μg, respectively) during the treatment period.
^‡ Clinically significant thrombocytopenic events were defined as a platelet count <50 × 10⁹/L starting at from week 3 of cycle 1 of treatment or receipt of platelet transfusion at any time. Patients who were randomized but later found to be ineligible were counted as not having a clinically significant thrombocytopenic event.
^§ Patients who were randomized but later found to be ineligible were counted as not having any lenalidomide dose reductions or delays.
^¶ Complete or partial response based on 2006 modified IWG guideline[28]. Patients who were randomized but later found to be ineligible were counted as not having achieved an MDS treatment response.
^∥ Erythroid response is defined based on the modified IWG criteria as hemoglobin increase by ≥1.5 g/dL or relevant reduction in units of red blood cell transfusions by an absolute number of ≥4 red blood cell transfusions/8 weeks.

ISSN: 1756-8722