Abstract
Purpose:
To evaluate the efficacy of recombinant human tumor necrosis factor alpha (rh-TNF-α) of adalimumab (Humira; Abbott Laboratories, North Chicago, IL, USA) repackaged into plastic polypropylene vials (Eppendorf®; Hamburg, Germany) and stored at 4°C for potential intravitreal use.
Methods:
Three samples of adalimumab refrigerated at 4°C for 5 weeks in plastic polypropylene vials (0.1, 1, 10 μg/ml) were used to neutralize the cytotoxic effect of rh-TNF-α on mouse fibrosarcoma cell line (L929 cells). The RTCA xCELLigence system was used to measure the cytotoxic effect of rh-TNF-α on L929 cells. L929 cell survival was assessed after treatment with the effective dose of rhTNF-α and the different concentrations of adalimumab stored in plastic vials. Rh-TNF-α was also used alone in parallel for each experiment to accurately determine the neutralization effect of the used antibody.Cell survival was measured at the same concentrations of adalimumab stored at 4°C for 5 weeks taken from the original commercial glass vials. The inhibitory response of adalimumab (anti-TNF-α) in terms of cell survival was measured at 1-hour intervals for up to 48h at week one and week five using the RTCA xCELLigence system.
Results:
The effective dose of rhTNF-α was determined to be 100ng/ml with a 40% mean cell survival at 48 hours. Adalimumab at concentrations of 1 and 10 μg/ml from the repackaged plastic vials stored for 5 weeks at 4°C was able to neutralize the cytotoxic effect of 100ng/ml rhTNF-α. 100% of cells survived compared to 8% survival when treated in parallel with rhTNF- α alone at 48 hours. However, for the very low concentration (0.1 μg/ml), the neutralizing effect of adalimumab decreased by 60 % and 80 % at 48 hours after treatment, at weeks 3 and 5 respectively. On the other hand, all concentrations of adalimumab (0.1, 1 and 10 μg/ml) taken from original glass vials were able to achieve neutralization of the 100ng/ml rhTNF-α with up to 90% cell survival at 48hours after 5 weeks storage at 4°C. This is compared to 30% cell survival when treated in parallel with 100ng/ml rhTNF-α alone.
Conclusions:
Adilamumab stored in plastic vials retained its efficacy in neutralizing the effect of rh-TNF-α after five weeks of storage at 4°C at concentration as low as 1 μg/ml.