Table 1.

Response criteria for hematologic improvement for MDS patients undergoing therapy

Item	Suggested modified IWG 2018 criteria	IWG 2006 criteria
Baseline criteria Definition of TB categories Pretreatment RBC TRSFN policy	3 groups NTD = (0 RBC in 16 wks) LTB = (3-7 RBC in 16 wks in at least 2 TRSFN episodes, max 3 in 8 wks) HTB = (≥8 RBC in 16 wks, ≥ 4 in 8 wks) TRSFN policy for the individual pt prior to the therapy should be monitored on treatment. Baseline Hb level <10 g/dL as prerequisite for pts in need of therapy	2 groups TD = (at least 4U of RBC with 8 wks for Hb < 9 g/dL) TID = (<4U of RBC with 8 wks for Hb <9 g/dL) TRSFN threshold of 9 g/dL, no exception for clinical indication. Baseline Hb level <11 g/dL as prerequisite for pts in need of therapy
Response evaluation criteria: HI-E  NTD  LTB  HTB	At least 2 consecutive Hb measurements ≥ 1.5 g/dL for a period of min 8 wks in observation period of 16-24 wk compared with lowest mean of 2 Hb measurements (apart from any TRSFN) with 16 wks before treatment onset** HI-E in LTB pts corresponds to TRSFN independence, defined by the absence of any TRSFN for at least 8 wks in an observation period of 16-24 wks with the same TRSFN policy compared with 16 wks prior to the treatment** Major response: Defined as TRSFN independent (TID) and requires the absence of any TRSFN over a period of min 8 wks in an observation period of 16-24 wks with the same transfusion policy compared with the 16 wks prior to treatment** Minor response: defined as a reduction by at least 50% of RBC over a min of 16 wks with the same transfusion policy compared with 16 wks prior to treatment	Hb increase by 1.5 g/dL and/or relevant reduction of U of RBC TRSFN by an absolute number of at least 4 RBC TRSFN/8 wks compared with the pretreatment transfusion number in the previous 8 wks; only RBC TRSFN given for a Hb of ≤9 g/dL pretreatment will count in the RBC TRSFN response evaluation
Platelet response (pretreatment PLT <100 x 109/L) HI-P	No change from 2006 criteria except: Evolution of bleeding symptoms is to be taken into account and 2. increments of platelets also for pts with pretreatment PLT >100 x 109 are to be reported	Absolute increase of 30 x 109/L for pts starting with >20x109/L platelets Increase from <20 x 109/L to >20 x 109/L and by at least 100%
Neutrophil response (pretreatment ANC<1.0 x109/L) HI-N	No change from 2006 criteria except: Increments for neutrophils also for pts with pretreatment ANC count of >1.0 x 109/L are to be reported	At least 100% increase and absolute increase >0.5 x 109/L

Abbreviations are as follows: ANC = absolute neutrophil count, Hb = hemoglobin, HTB = high transfusion burden, min = minimum, NTD = not transfusion dependent, pt = patient, PLT = platelet count, TRSFN = transfusion, TB = transfusion burden, RBC = red blood cells, TD = transfusion dependent, TID = transfusion independent, LTB = low transfusion burden.

^*Adapted from Cheson, et al¹⁰ and Platzbecker, et al.¹¹

^**Only a response duration of at least 16 weeks, however, is considered clinically meaningful.