Defibrotide improves survival in post-HSCT patients with veno-occlusive disease
Treatment with defibrotide is safe and effective for patients with veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), following either allogeneic or autologous haematopoietic stem cell transplant (HSCT), according to the results of a study presented at the 59th American Society of Hematology (ASH) Annual Meeting and Exhibition in Atlanta, Georgia.
“In this posthoc analysis of T-IND (an expanded-access protocol) transplant groups, day +100 survival rates in both allograft and autograft patients with VOD/SOS, with and without multiorgan dysfunction (MOD), were consistent with prior defibrotide studies,” researchers said.
A total of 1,000 post-HSCT patients received defibrotide from 2007 to 2016, of whom 843 (52 percent paediatric; 48 percent adult; 450 had MOD) received allografts and 155 (82 percent paediatric; 18 percent adult; 61 had MOD) received autografts; two patients had unknown graft types. [ASH 2017, abstract 3224]
Neuroblastoma and acute leukaemias were most common in the autograft and allograft group, respectively.
In the allograft group, the Kaplan-Meier estimated survival rate at day +100 was 55 percent (95 percent CI, 52‒58 percent) overall, 47 percent (43‒52 percent) for those with MOD, and 64 percent (59‒69 percent) for those without MOD. In the autograft group, the survival rate was 80 percent (72‒85 percent) overall, 67 percent (53‒77 percent) for those with MOD, and 88 percent (80‒93 percent) for those without MOD.
Seventy-four percent of allograft patients (in 77 percent of the MOD subgroup) and 53 percent of autograft patients (in 64 percent of the MOD subgroup) experienced adverse events (AEs), with haemorrhage and hypotension being more common postallograft (31 and 13 percent, respectively) than postautograft (17 and 7 percent).
There were treatment-related AEs (TRAEs) in 21 percent of allograft patients (22 percent with MOD) and 20 percent of autograft patients (30 percent with MOD), with pulmonary haemorrhage (allograft, 5 percent; autograft, 3 percent), gastrointestinal haemorrhage (allograft, 3 percent; autograft, 1 percent), and epistaxis (allograft, 2 percent; autograft, 2 percent) being the most common.
TRAEs leading to treatment discontinuation were more frequent postallograft (13 percent) than postautograft (10 percent), with pulmonary haemorrhage (allograft, 4 percent; autograft, 3 percent) and gastrointestinal haemorrhage (allograft, 2 percent; autograft, 0.6 percent) being the most common.
TRAEs leading to death occurred in 3 and 0.6 percent of the allograft and autograft group, respectively, with pulmonary haemorrhage (allograft, 1 percent; autograft, 0.6 percent) as the most common.
“For both allogeneic and autologous transplant groups, the higher survival rates in the subgroups of patients without vs those with MOD indicate that further study is warranted to determine the impact of treatment earlier in the course of VOD/SOS,” researchers said.
In this study, patients were administered defibrotide 25 mg/kg/day in four divided doses and were recommended treatment for ≥21 days. The original eligibility criteria were VOD/SOS by biopsy or Baltimore criteria (bilirubin ≥2 mg/dL and ≥2 of: hepatomegaly, ascites, ≥5 percent weight gain) post-HSCT, with MOD (renal and/or pulmonary); the protocol was amended to include patients after chemotherapy without HSCT (off label), patients without MOD (off label), and patients with VOD/SOS per modified Seattle criteria (≥2 of: bilirubin >2 mg/dL, hepatomegaly, or ≥5 percent weight gain).
An unpredictable and life-threatening complication of conditioning for HSCT, VOD/SOS has an estimated overall incidence of 13.7 percent post-HSCT, and VOD/SOS with MOD is associated with >80 percent mortality, according to researchers.