Blood cells: excitable at last

A third course of anti-thymocyte globulin in aplastic anaemia is only beneficial in previous responders

This retrospective study evaluated the outcome of 18 patients with aplastic anaemia treated with a third course of anti-thymocyte globulin (ATG)-containing immunosuppressive therapy (IST). Of the 18 patients, seven had responded to one of the previous courses of ATG and 11 were refractory to both the previous courses. Self-limiting grade >/=3 liver toxicity was observed in three patients. Two patients had to discontinue ATG because of severe systemic side effects. The incidence and manifestations of serum sickness did not appear to be different during the three courses. All of the seven patients that previously responded to one of the courses responded to a third course. In contrast, of 11 patients refractory to the previous courses, only two had a transient partial response. The 3-yr event-free survival for the patients who had responded to one of the previous courses of ATG was significantly superior to that of patients refractory to both the previous courses of ATG (83% vs. 0%, P = 0.0001). For aplastic anaemia patients, a third course of ATG-containing IST is a reasonable option in previous responders. Patients refractory to previous two courses of ATG have a much lower response rate and may be suitable candidates for novel therapeutic options.

Interferon α therapy for patients with essential thrombocythemia

BACKGROUND

In 1986, a Phase II trial of recombinant interferon-alpha (IFN-alpha) was initiated as therapy for patients with essential thrombocythemia (ET).

METHODS

Patients were treated with subcutaneous IFN-alpha at a dose of 5 x 10(6) units/m(2) daily. In responding patients, the therapy lasted at least 3 years.

RESULTS

Twenty-three patients (14 females and 9 males; median age, 41 years; age range, 20-63 years) with a median platelet count of 1350 x 10(9)/L were treated. After a median follow-up of 174 months (14.5 years), 15 of 20 evaluable patients (75%) responded, including 14 patients who achieved a complete hematologic response (CHR) (6 of them with bone marrow remission) and 1 patient who demonstrated a partial response. The median time to response was 6 months (range, 0.5-36 months), and the median response duration was 48 months (range, 5-114 months). Seven patients who achieved a CHR and were taken off therapy after they completed 3 years of maintenance therapy sustained their response for a median of 28 months. No symptoms or signs of thrombosis or hemorrhage were observed in responding patients. Eleven of 14 patients (78%) who achieved a CHR developed a recurrence, and 2 of 5 patients with recurrences who were rechallenged with IFN-alpha achieved a second response. The treatment was tolerated relatively well.

CONCLUSIONS

IFN-alpha was safe and effective therapy for patients with ET, and the ability of IFN-alpha to reverse disease pathology and possibly modify the clinical course of patients with ET warrants its investigation in larger, prospective trials.