Defibrotide beneficial for post-HSCT VOD/SOS patients
Defibrotide treatment may be beneficial to adult patients with posthematopoietic stem cell transplantation (HSCT) hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS), reports a new study presented at the concluded 59th American Society of Haematology Annual Meeting (ASH 2017).
Moreover, overall survival at day +100 after HSCT was low both in the overall adult population and in those with late-onset VOD/SOS, indicating the importance of surveillance for new VOD/SOS beyond day +21 post-HSCT.
The study included 430 adults with VOD/SOS post-HSCT (mean age 40.3±15.9 years; 55.1 percent male) who were given 25 mg/kg/day of defibrotide for ≥21 days. In an exploratory analysis of the timing of initiation, the researchers found that earlier defibrotide initiation may lead to significantly better day +100 survival rates. [ASH 2017, abstract 3225]
For instance, the survival rates for those with no delay (n=120), a delay of 1 day (n=112), and a delay of 2 days (n=53) in defibrotide treatment following VOD/SOS diagnosis were high at approximately 50 percent, as opposed to the 4-day (n=27) or 5-day (n=22) delay groups, in which survival rates were around 40 percent.
Survival rates for those with 3-day (n=36), 6-day (n=9), and 7-day (n=9) delays in defibrotide treatment were even lower at around 30 percent. The trend between lower survival rates and treatment delay reached borderline significance in the Cochran-Armitage trend test (p=0.055).
The study also included 169 late-onset post-HSCT VOD/SOS patients (mean age 43.1±15.1 years; 49.1 percent male), in which disease onset was noted only after day +21. The safety profile was comparable between the overall adult and late-onset groups, with respective treatment-emergent adverse event (AE) prevalence rates of 77.9 and 78.1 percent.
Gastrointestinal and pulmonary haemorrhage were the most common treatment-related AEs that led to treatment discontinuation.
Overall survival analyses were also performed on patient subsets and showed that patients with multiorgan dysfunction had lower day +100 survival rates, both in the overall adult (39.0 percent) and late-onset (43.0 percent) groups. In comparison, those without multiorgan dysfunction consistently had higher day +100 survival, with respective rates of 56.5 and 55.1 percent in the overall adult and late-onset groups.
The findings of the current study present the final outcomes of the expanded-access protocol study, the largest prospective study of the efficacy of defibrotide on adults with post-HSCT VOD/SOS with or without MOD.
“The survival rate in adults with VOD/SOS post-HSCT is consistent with prior results for adults receiving defibrotide, and support the clinical utility of defibrotide for treatment for post-HSCT VOD/SOS in adults,” the researchers said. [Biol Blood Marrow Transplant 2016;22:1874-1882; Biol Blood Marrow Transplant 2010;16:1005-1017]