Interleukin-2 therapy after bone marrow or stem cell transplantation for hematologic malignancies

Area of Science:

• Hematology
• Immunotherapy
• Oncology

Background:

• Hematologic malignancies often have high relapse rates after autologous or allogeneic bone marrow transplantation (BMT) or stem cell transplantation (SCT).
• Consolidative immunotherapy with recombinant interleukin-2 (rIL-2) early post-transplant is hypothesized to reduce relapse by targeting minimal residual disease.

Purpose of the Study:

• To investigate the safety, immunomodulatory effects, and clinical benefits of rIL-2 therapy following autologous and allogeneic BMT/SCT.
• To evaluate preliminary results from studies assessing rIL-2 as a consolidative immunotherapy after transplantation for advanced hematologic malignancies.

Main Methods:

• Patients with hematologic malignancies received autologous or allogeneic BMT/SCT followed by rIL-2 via continuous intravenous infusion.
• A specific rIL-2 regimen involving induction and maintenance doses was administered.
• Phase I, feasibility, and phase I/II trials were conducted using different rIL-2 preparations and in combination with lymphokine-activated killer cells.

Main Results:

• An rIL-2 regimen was identified as tolerable early post-transplantation.
• rIL-2 administration significantly increased CD3+CD8+ T lymphocytes and CD3-CD56+ natural killer cells.
• Enhanced antitumor cytolytic activity of immune cells was observed, with encouraging but inconsistent clinical outcomes in phase I/II trials.

Conclusions:

• The identified rIL-2 regimen is safe and immunomodulatory post-transplantation.
• Preliminary results warrant further investigation in larger trials.
• Prospectively randomized phase III trials are justified to confirm if rIL-2 improves outcomes and reduces relapse rates after autologous SCT for advanced hematologic malignancies.