Allo-HSCT in patients with high-risk MDS: Analysis from the BMT CTN 1102 trial

Context

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for patients with myelodysplastic syndromes (MDS).¹ To assess the impact of the presence of high-risk mutations on outcomes following allo-HSCT, Versluis et al.¹ performed a genetic analysis of the Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 1102 trial. Findings were recently published in the Journal of Clinical Oncology which we are pleased to summarize below.

Study design and patient population

• Targeted DNA sequencing using a variant allele fraction cutoff of 0.02 was performed on blood samples from 309 out of 384 patients from the multicenter phase II BMT CTN 1102 study (NCT02016781). The study compared reduced intensity conditioning allo-HSCT with hypomethylating therapy or best supportive care in patients aged 50–75 with International Prognostic Scoring System intermediate-2 or high-risk de novo MDS.
• Baseline characteristics and mutation frequency were similar between patients who underwent allo-HSCT (donor arm) and those who did not (no-donor arm) (Table 1).
• Median follow-up in survivors was 32 months (range, 6–38 months).

Table 1. Most common somatic gene mutations in patients in the BMT CTN 1102 trial with samples available*

BMT CTN, Blood and Marrow Transplant Clinical Trials Network. *Data from Versluis et al.1 †More patients who underwent allo-HSCT (donor arm; 88.1%) had samples available versus patients who did not receive allo-HSCT (no donor arm; 64.5%; p < 0.001).
Gene mutation frequency, %	Donor arm (n = 229)†	No donor arm (n = 80)†	p value
≥ 1 mutation	88
TP53	28	29	0.89
ASXL1	23	29	0.37
SRSF2	16	16	0.99
DNMT3A	17	10	0.20

Key findings

• Patients with TP53 or KMT2A-partial tandem duplication (PTD) mutations had inferior 3-year overall survival (OS) compared with patients without these mutations (univariate analysis; Figure 1).

BMT CTN, Blood and Marrow Transplant Clinical Trials Network; OS, overall survival; PTD, partial tandem duplication.
*Data from Versluis et al.¹

 Multivariable analysis found (Figure 2):

• TP53, KMT2A-PTD, and DDX41 mutations were associated with OS.

• Patients in the donor arm had improved OS vs the no donor arm.
• The allelic state of TP53 mutations was associated with inferior outcomes.

In addition, allo-HSCT time-dependent covariate analysis revealed:

• an association between the presence of TP53 or KMT2A-PTD mutations, and inferior OS;
• patients who received allo-HSCT (n = 197) also had a lower instantaneous risk of death when compared to patients who did not (n = 78; hazard ratio, 2.31; 95% confidence interval, 1.53–3.49; p < 0.001); and
• in patients with TP53 mutations, OS was improved in those who underwent HSCT vs those who did not (hazard ratio, 3.89; 95% confidence interval, 1.87–8.12; p < 0.001; multivariable analysis).

Allo-HSCT, allogeneic hematopoietic stem cell transplantation; ECOG, Eastern Cooperative Oncology Group; HR; hazard ratio; IPSS; International Prognostic Scoring System; MDS, myelodysplastic syndromes; OS, overall survival; PTD, partial tandem duplication.
*Adapted from Versluis et al.¹

Key learnings

Allo-HSCT can be beneficial in patients with high-risk MDS, including patients with TP53 mutations.