pentostatin and Hematologic-Diseases

Acute graft-versus-host disease (aGVHD) following allogeneic hematopoietic cell transplant (HCT) is the major reason for nonrelapse mortality (NRM), and thus is a major determinant of long-term survival. Clinical trials of new aGVHD treatments are needed to identify approaches that will ultimately improve upon HCT survival. At present, it is not clear how quickly response to GVHD treatment needs to be established to reliably categorize patients at high risk for death or to promptly identify those who might benefit from alternate treatment. Therefore, we analyzed time to response from onset of aGVHD treatment in 180 patients who were enrolled on a national, randomized, phase II aGVHD treatment clinical trial whose initial treatment of GVHD consisted of high-dose steroids plus a second immunosuppressive agent. The aim of this analysis was to determine whether time to aGVHD treatment response predicts patient outcomes, especially survival. We used response at 14, 28, and 56 days from initiation of aGVHD treatment to categorize patients for NRM and survival. Multivariate analyses and specificity/sensitivity analyses identified that day 28 response (complete or partial response) best categorized patients by NRM and survival at 9 months from start of aGVHD treatment. If verified as a reliable predictor of late outcomes following other aGVHD treatment approaches, day 28 response should serve as a standard early endpoint for future trials of aGVHD therapy.

Topics: Adrenal Cortex Hormones; Adult; Diphtheria Toxin; Etanercept; Graft vs Host Disease; Hematologic Diseases; Hematopoietic Stem Cell Transplantation; Humans; Immunoglobulin G; Interleukin-2; Methylprednisolone; Middle Aged; Pentostatin; Receptors, Tumor Necrosis Factor; Recombinant Fusion Proteins; Survival Analysis; Treatment Outcome

Pentostatin, a novel inhibitor of adenosine deaminase, has shown activity in various lymphoid malignancies of both the T and B cell lineage. This agent has unique side effects and in general myelosuppression has been mild. Interferon has both antiviral and antineoplastic properties. This agent has shown activity in hairy cell leukemia, chronic granulocytic leukemia, low grade lymphoma, and myeloma. Side effects from interferon are in general dissimilar to those that have been seen with pentostatin and in particular myelosuppression has not been a major toxicity with low doses of interferon. This current trial explored the combination of pentostatin and interferon in hematologic malignancies. Fifteen patients were enrolled in this phase I trial at a fixed dose of pentostatin of 4 mg/m2 biweekly and interferon at doses of 0.5, 1, 2, or 4 million units/m2 of interferon. At the first three dose levels of interferon nausea and vomiting were the predominant toxicity and appeared to worsen with time on study. Fatigue also was seen at the lowest level of interferon and was severe enough to cause two individuals to discontinue the study medications. At higher dose levels of interferon, myelosuppression, nausea and vomiting, and fatigue were the predominant toxicities. One patient with hairy cell leukemia had a complete response and a second patient with T cell cutaneous lymphoma had a partial response which lasted for 6 to 7 weeks. The maximum tolerated dose of interferon with pentostatin in this patient population was four million units/m2.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Drug Evaluation; Female; Hematologic Diseases; Humans; Interferon Type I; Leukemia; Lymphoma; Male; Middle Aged; Monitoring, Physiologic; Pentostatin; Remission Induction