MRD predicts outcome of HSCT in ALL, study suggests

Compared to patients with a matched sibling donor, the HR for patients with a mismatched donor was 1.41, and the score was 1. For patients who received cord blood from an unrelated donor, the HR was 1.48, and the score was 1.

Compared to patients with T-cell ALL, the HR for patients with pre-B ALL was 1.35, and the score was 1.

Compared to patients with MRD <10^-4, the HR for patients with MRD ≥10^-4 was 2.32, and the score was 2.

The probability of EFS at 18 months was 78% ± 2% for patients with 0 to 1 points, 54% ± 3% for those with 2 to 3 points, and 46% ± 5% for patients with 4 or more points.

Day 30 post-HSCT risk score

When considering patients at day 30 post-HSCT, factors that predicted 18-month EFS included remission status, donor type, immunophenotype, aGVHD status, and MRD.

The HR for patients in early second CR was 2.51, and the score was 3. For patients in third CR or greater, the HR was 2.09, and the score was 2.

The HR for patients with a mismatched donor was 1.75, and the score was 2. The HR for patients with pre-B ALL was 1.40, and the score was 1.

Compared to patients with grade 1-2 aGVHD, the HR was 2.02 for patients with grade 0 aGVHD, and the score was 2. For patients with grade 3 aGVHD, the HR was 1.44, and the score was 1. For patients with grade 4 aGVHD, the HR was 7.12, and the score was 7.

The researchers evaluated MRD prior to HSCT and MRD at day 30, using a reference of MRD <10^-4 at both time points. For patients with MRD <10^-4 pre-HSCT and ≥10^-4 at day 30, the HR was 2.29, and the score was 2.

For patients with MRD ≥10^-4 pre-HSCT and <10^-4 at day 30, the HR was 3.17, and the score was 3. For patients with MRD ≥10^-4 pre-HSCT and at day 30, the HR was 3.63, and the score was 4.

The probability of EFS at 18 months was 80% ± 2% for patients with 0 to 3 points, 54% ± 4% for those with 4 to 6 points, and 25% ± 6% for those with 7 or more points.

Day 90 post-HSCT risk score

When considering patients at day 90 post-HSCT, factors that predicted 18-month EFS included remission status, aGVHD status, and MRD.

For patients in early second CR, the HR was 2.81, and the score was 3. For those in third CR or greater, the HR was 1.85, and the score was 2.

Compared to patients with grade 1-2 aGVHD, the HR was 1.60 for patients with grade 0 aGVHD, and the score was 2. For patients with grade 4 aGVHD, the HR was 2.49, and the score was 2.

The researchers assessed MRD prior to HSCT and MRD at day 90, using a reference of MRD <10^-4 at both time points. For patients with MRD <10^-4 pre-HSCT and ≥10^-4 at day 90, the HR was 6.03, and the score was 6.

For patients with MRD ≥10^-4 pre-HSCT and <10^-4 at day 90, the HR was 3.11, and the score was 3. For patients with MRD ≥10^-4 pre-HSCT and at day 90, the HR was 4.59, and the score was 5.

The probability of EFS at 18 months was 83% ± 2% for patients with 0 to 2 points, 60% ± 4% for those with 3 to 5 points, and 17% ± 11 for those with 6 or more points.