Summary of TCT 2020 highlights – GvHD prophylaxis

This article was generated based on an overview of the International Academy for Clinical Hematology webinar delivered by Bipin Savani on April 1, 2020. It is the third in a series summarizing the highlights from the Transplantation & Cellular Therapy (TCT) 2020 meeting.

Abstract 77: A phase II study of sirolimus-based calcineurin inhibitor-free GvHD prophylaxis after peripheral blood haploidentical transplantation with post-transplant cyclophosphamide¹

Haploidentical-hematopoietic stem cell transplantation (haplo-HSCT) is increasingly offered to patients with hematological malignancies. Previous studies have demonstrated that haplo-HSCT with peripheral blood (PB) as a graft source and post-transplant cyclophosphamide (PTCy) plus calcineurin inhibitor and mycophenolate mofetil (MMF) as graft-versus-host disease (GvHD) prophylaxis leads to a lower risk of relapse however at the cost of increased acute and chronic GvHD.

In a single institution phase II study NCT03018223, the authors of this abstract investigated whether sirolimus plus PTCy and MMF as an calcineurin inhibitor-free GvHD prophylaxis could reduce the risk of acute GvHD (aGvHD) after PB haplo-HSCT from the current benchmark of 40% down to 20%.

Sirolimus at 8-14ng/ml was administered from Day 5 to Day 90 after HSCT, followed by tapering before discontinuation by Day 180 in the absence of GvHD.

Patient characteristics

• In total, 32 patients were enrolled on the study; baseline characteristics are described in Table 1

Table 1. Patient characteristics

Results

• All patients engrafted, with median neutrophil engraftment of 17 (12–30) days and median platelet engraftment of 25.5 (12–63) days
• None of the patients developed severe cytokine release syndrome
• GvHD
  • At Day 100, 18.8% (95% CI, 7.5–34.0) of patients developed Grade II–IV aGvHD, including 9.4% (95% CI, 2.3–22.5) of patients Grade III–IV
  • At one year, 20% (95% CI, 7.9–36.0) developed moderate/severe chronic GvHD (cGvHD), with three patients requiring steroid therapy
• 1-year non-relapse mortality and relapse were 19.7% (95% CI, 7.8–35.5) and 23.7% (95% CI, 10.2–40.4), respectively
• 1-year disease-free survival and overall survival were 56.6% (95% CI, 41.3–77.7) and 70.2% (95% CI 55.5–88.6), respectively

Conclusions

The study demonstrated that sirolimus plus PTCy/MMF can be an effective regimen to prevent Grade II–IV aGvHD after haplo-HSCT using PB. Moreover, the therapy resulted in a low rate of cGvHD cases. The authors suggest a prospective clinical trial to compare sirolimus based PTCy/MMF regimen with tacrolimus based PTCy/MMF regimen.

Read more about sirolimus based therapies, for GvHD prophylaxis and treatment.

Other key abstracts from the TCT 2020 meeting

Other important abstracts mentioned in the webinar already covered on the AML Hub are

Table 2. Other TCT meeting 2020 highlight abstracts