Ingunn Dybedal

Summary. We have published previously a prototype of a decision model for anaemic patients with myelodysplastic syndromes (MDS), in which transfusion need and serum erythropoietin (S‐Epo) were used to define three groups with different probabilities of erythroid response to treatment with granulocyte colony‐stimulating factor (G‐CSF) + Epo. S‐Epo ≤ 500 U/l and a transfusion need of < 2 units/month predicted a high probability of response to treatment, S‐Epo > 500 U/l and ≥ 2 units/month for a poor response, whereas the presence of only one negative prognostic marker predicted an intermediate response. A total of 53 patients from a prospective study were included in our evaluation sample. Patients with good or intermediate probability of response were treated with G‐CSF + Epo. The overall response rate was 42% with 28·3% achieving a complete and 13·2% a partial response to treatment. The response rates were 61% and 14% in the good and intermediate predictive groups respectively. The model retained a significant predictive value in the evaluation sample ( P < 0·001). Median duration of response was 23 months. Scores for global health and quality of life (QOL) were significantly lower in MDS patients than in a reference population, and fatigue and dyspnoea was significantly more prominent. Global QOL improved in patients responding to treatment ( P = 0·01). The validated decision model defined a subgroup of patients with a response rate of 61% (95% confidence interval 48–74%) to treatment with G‐CSF + Epo. The majority of these patients have shown complete and durable responses.

Treatment with erythropoietin (epo) may improve the anemia of myelodysplastic syndromes (MDS) in approximately 20% of patients. Previous studies have suggested that treatment with the combination of granulocyte colony-stimulating factor (G-CSF) and epo may increase this response rate. In the present phase II study, patients with MDS and anemia were randomized to treatment with G-CSF + epo according to one of two alternatives; arm A starting with G-CSF for 4 weeks followed by the combination for 12 weeks, and arm B starting with epo for 8 weeks followed by the combination for 10 weeks. Fifty evaluable patients (10 refractory anemia [RA], 13 refractory anemia with ring sideroblasts [RARS], and 27 refractory anemia with excess blasts [RAEB]) were included in the study, three were evaluable only for epo as monotherapy and 47 for the combined treatment. The overall response rate to G-CSF + epo was 38%, which is identical to that in our previous study. The response rates for patients with RA, RARS, and RAEB were 20%, 46%, and 37%, respectively. Response rates were identical in the two treatment groups indicating that an initial treatment with G-CSF was not neccessary for a response to the combination. Nine patients in arm B showed a response to the combined treatment, but only three of these responded to epo alone. This suggests a synergistic effect in vivo by G-CSF + epo. A long-term follow-up was made on 71 evaluable patients from both the present and the preceding Scandinavian study on G-CSF + epo. Median survival was 26 months, and the overall risk of leukemic transformation during a median follow-up of 43 months was 28%. Twenty patients entered long-term maintenance treatment and showed a median duration of response of 24 months. The international prognostic scoring system (IPSS) was effective to predict survival, leukemic transformation, and to a lesser extent, duration of response, but had no impact on primary response rates.