Long-Term Clinical Outcome of Patients with Acquired Aplastic Anemia In Brazil Using Cyclosporine-A (CSA) and Prednisone (PRED): 20 Years Follow-up From a Single Institution
Authors: Medeiros Larissa A , Nabhan Samir K , Bitencourt Marco Antonio , Oliveira Michel M. , Funke Vaneuza A M , Franco Vivian K B , Setubal Daniela C. , Sola Caroline B S , Nunes Elenaide C , Bonfim Carmem , Neto José Zanis , Pasquini Ricardo 
Published: October 2019

Abstract
Abstract 2234

Introduction/Background:
Immunosuppressive therapy is the best alternative for patients with severe aplastic anemia (SAA) without matched sibling donor or with age > 40 years. Since 1988, an alternative protocol was developed with cyclosporine (CSA) and prednisone (PRED) due to irregularity in distribution of anti-thymocyte globulin (ATG) in Brazil. This study aims to show the results of this treatment on the quality of response, overall survival and development of clonal evolution.

Materials and methods:
384 patients diagnosed with SAA (Camitta and Bacigalupo criteria) were evaluable by medical records review from 12/1988 to 12/2008. The immunosuppressive therapy consisted of CSA: 12mg/kg/day BID from day (D)1- D8, then 7mg/kg/day BID until 1 year. After that CSA was progressively tapered (5% each month) and ultimately stopped usually by two years. CSA levels were kept between 200–400ng/ml. PRED: 2mg/kg/day from D1-D14 then 1mg/kg/day from D15- D45. From that day on PRED dose was tapered 20% each week. Sulfamethoxazole-trimethoprim and fluconazole were used for prophylaxis against Pneumocystis jiroveci (P carinni) and fungal diseases, respectively. Treatment response was defined as Table 1.
Treatment evaluation was performed at 6 weeks, 3, 6 and 12 months and then yearly. At diagnosis: median age was 21 years (2-75), disease duration 95 days (2-4749), and median number of transfusions were 12 (0-200). Etiology was idiopathic in 78%. In peripheral blood, median hemoglobin was 7.4g/dL, granulocytes 580/uL, platelets 12.000/uL and reticulocyte 0.5% (corrected value). 60% of the patients had not been treated previously.

Results:
Overall survival was 61% ± 3 with a median follow-up of 7 years (range: 2 months - 23 years). Response to treatment: 51% had some degree of response, with good quality of life and transfusions independent (143 patients with complete response and 53 partial response). 36 patients had no response and there were 96 deaths. Fifty six patients have lost follow-up. Most patients achieved response between 3 and 6 months of therapy. In multivariate analysis the number of neutrophils ≥ 200/uL (p = 0.009), platelets ≥ 12.000/uL (p = 0.018), reticulocyte ≥ 0.5% (p <0.001) and starting treatment after 1997 (p = 0.002) had an impact on overall survival. Patients with 15 or more previous transfusions (p = 0.006) and age ≥ 40 years (p = 0.003) had lower survival. Overall survival was 63% ± 4 and 42% ± 6 for for patients with severe disease and very severe aplastic anemia (p <0.001). The subgroup analysis of patients under 10 years old had similar results. Among patients with response, thirty-four remained dependent of CSA. Cumulative incidence of relapse was 28% ± 4 within a median of 4.4 years. Hypertension, gingival hypertrophy and diabetes mellitus were common, but easily controlled. The rate of clonal evolution among this cohort was 7.81% (16 patients developed Paroxysmal Nocturnal Hemoglobinuria, 9 Myelodysplastic Syndrome and 5 Acute Myeloid Leukemia).

Conclusion:
This study, with a long follow-up, has demonstrated that the overall survival using CSA and PRED is similar to that reported with ATG therapy. Even patients with partial responses had achieved good quality of life, free from transfusions and infections. Survival was influenced by the neutrophils, platelet counts, reticulocyte, number of transfusions, age at diagnosis, and therapy started after 1997. The incidence of clonal evolution was lower when compared to reported trials with ATG + CSA.

Disclosures:
Oliveira: Alexion: Speakers Bureau. Funke: Novartis, Bristol: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Pasquini: Novartis, Bristol: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.