Comparisons Between Frontline Therapy and a Combination of Eltrombopag Plus Immunosuppression Therapy and Human Leukocyte Antigen-Haploidentical Hematopoietic Stem Cell Transplantation in Patients With Severe Aplastic Anemia: A Systematic Review

Porcine Anti-Lymphocyte Globulin, Cyclosporine A Plus Thrombopoietin Receptor Agonists Achieved Similar Efficacy and Survival Compared to Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Aplastic Anemia

Background

Immunosuppressive therapy (IST) with horse or rabbit anti-human thymocyte immunoglobulin (h-/r-ATG) and hematopoietic stem cell transplantation (HSCT) are two baseline treatments for severe aplastic anemia (SAA) and transfusion-dependent non-severe aplastic anemia (TD-NSAA) patients. Addition of thrombopoietin receptor agonists (TPO-RAs) to standard IST therapy (h-/r-ATG) has greatly improved the survival of SAA, whereas porcine anti-lymphocyte globulin (p-ALG) combined with TPO-RAs still had a matter of debate.

Methods

We retrospectively compared the data of 48 AA patients in our center between 2020 and 2022, 23 AA patients received with p-ALG ± TPO-RAs, 25 AA patients underwent matched sibling donor (MSD-) or haploidentical (haplo-) HSCT.

Results

For patients in the HSCT group, the ORR was 90.9% which was significantly higher than that in the IST±TPO-RAs group (45.5%, P = 0.001) at 3 months; moreover, patients who underwent HSCT achieved faster transfusion independence, better CR rate, shorter time of recovery normal blood routine, and the percentage of normal blood routine (all P < 0.05) compared with IST±TPO-RAs group. However, the ORR were similary at 6 months in the two groups (95.5% vs 81.8% P = 0.342), with a median follow up of 19.8 months (range, 0.3-38.2 months), the 2-year FFS and OS in the two cohorts has no different. Subgroup analysis further indicated that the 2-year FFS and OS were similar between IST+TPO-RAs and haplo-HSCT subgroups, as well as in IST+TPO-RAs and MSD-HSCT cohorts. Moreover, the first-time hospitalizations were much more expensive in the HSCT group than in the IST±TPO-RAs group (402 756 vs. 292 902 yuan, P = 0.002).

Conclusion

P-ALG-based-IST±TPO-RAs is a good treatment option with similar FFS and OS compared to allo- HSCT for AA patients without the opportunity of HSCT.

First-line treatment of severe aplastic anemia: immunosuppressive therapy plus eltrombopag versus haploidentical hematopoietic stem cell transplantation, a multicenter prospective study

Matched-related donor hematopoietic stem cell transplantation (HSCT) remains the preferred first-line option for severe aplastic anemia (SAA) patients aged <40 years even in the era of eltrombopag (EPAG). However, there has not been any direct comparison between immunosuppressive therapy (IST) plus EPAG (IST + EPAG) and haploidentical HSCT (Haplo-HSCT) as first-line therapy. This study prospectively compared the efficacy, safety and health-related quality of life (HRQoL) of Haplo-HSCT (n = 147) and IST + EPAG (n = 121) as first-line treatment for patients with SAA. The results showed that 86.3% of patients in the Haplo-HSCT group and 24.1% of patients in the IST + EPAG group achieved normal complete blood count (CBC) (P < 0.001) after 6 months of treatment. The time to achieve transfusion independence and absolute neutrophil count ≥ 1.0 × 109/L were shorter in the Haplo-HSCT group than in the IST + EPAG group (P < 0.05). In the IST + EPAG and Haplo-HSCT, 3-year overall survival (OS) was 92.4 ± 2.4% and 82.8 ± 3.1% (P = 0.017), whereas 3-year failure-free survival (FFS) was 69.4 ± 4.2% and 81.6 ± 3.2% (P = 0.002), respectively. Similar results were observed in patients with <40 years of age. Among patients with ≥40 years of age, there was no difference in 3-year OS (88.6 ± 4.8% vs. 82.4 ± 8.1%, P = 0.517) between the IST + EPAG and Haplo-HSCT groups, whereas 3-year FFS was lower in the IST + EPAG (58.7 ± 7.5% vs. 82.4 ± 8.1%, P = 0.043). Subgroup analysis for populations aged <40 years indicated that SAA benefited more from IST + EPAG, and very SAA (vSAA) benefited more from Haplo-HSCT. Patients treated with haplo-HSCT scored significantly better in the HRQoL than treated with IST + EPAG (P < 0.0001). Multivariate analysis showed that first-line Haplo-HSCT was associated with normal CBC at 6 months, better FFS and led to a better HRQoL (P < 0.001). In summary, the IST + EPAG achieved better OS for <40 years SAA patients, while the Haplo-HSCT accelerated hematopoietic recovery and HRQoL, achieved better FFS even for those <40 years vSAA and ≥40 years patients.

Comparable Outcomes and Health-Related Quality of Life for Severe Aplastic Anemia: Haploidentical Combined With a Single Cord Blood Unit vs Matched Related Transplants

We retrospectively compared the outcomes and health-related quality of life (HRQoL) of severe aplastic anemia (SAA) patients who received haploidentical hematopoietic stem cell transplantation with a single unrelated cord blood unit (Haplo-cord HSCT) (n = 180) or matched related donor (MRD)-HSCT (n = 128). After propensity score matching, we were able to match 88 patients in each group and to compare the outcomes between the two matched-pair groups. Haplo-cord recipients exhibited a longer median days for neutrophil engraftment (12 vs 11, P = 0.001) and for platelet engraftment (15 vs 13, P = 0.003). Haplo-cord recipients a high cumulative incidence of grades II–IV acute graft-versus-host disease (GVHD) (29.8 vs 14.0%, P = 0.006), while similar III–IV acute GVHD, total chronic GVHD, and moderate to severe chronic GVHD at four-year (all P < 0.05). Among the Haplo-cord HSCT and MRD-HSCT groups, the four-year GVHD-free/failure-free survival rates were 73.5% and 66.9% (P = 0.388) respectively, and the overall survival rates were 81.5% and 77.2% (P = 0.484), respectively. Similar comparable results also were observed between the corresponding first-line, older or younger than 40 years old subgroups. The Haplo-cord HSCT group exhibited higher scores in the physical component summary, physical functioning, general health and social functioning than the MRD-HSCT group (all P < 0.05). In the multivariate analysis, young age and Haplo-cord HSCT were favorable factors for HRQoL, while moderate to severe cGVHD was associated with lower HRQoL. These results suggest that for SAA patients, Haplo-cord HSCT could achieve at least comparable efficacy and HRQoL to MRD-HSCT.