Objective: We enterally administered a 14-day course of 3-mercapto-D-valine (D-penicillamine) to five extremely low birth weight (ELBW) neonates, as a step toward assessing this therapy as a means of reducing the incidence or severity of retinopathy of prematurity (ROP).
Methods: The study drug (100 mg/ml) was given by nasogastric tube at a dose of 100 mg/k every 8 h for three days, and then 50 mg/k once per day for 11 additional days. Logbooks were maintained by the bedside nurses to record signs of possible immediate intolerance. Laboratory tests assessed hepatic, renal, and hematologic toxicity. ROP was scored according to the ICROP guidelines. Comparisons were with a cohort of 139 consecutive recent neonates of the same birth weight and gestational age range.
Results: Five neonates were enrolled in the study, and all received the full course of study drug as planned. Signs of immediate intolerance of the study drug were not observed in any. The study patients did not have a higher incidence, than that of the cohort group, in creatinine elevation, thrombocytopenia, neutropenia, hyperbilirubinemia, or abnormal liver function test. Four of the five had no ROP and one developed transient stage 1, compared with a 54% occurrence of ROP in the cohort.
Conclusions: It is feasible to enterally administer a 14-day course of 3-mercapto-D-valine to ELBW neonates and the suspension appears to be well tolerated. These results suggest that phase II safety and preliminary efficacy trials can be undertaken.