Intravitreal Adalimumab in Retinitis Pigmentosa: A Prospective Pilot Study Assessing Ocular Safety and Feasibility

Objective The objective of this study was to evaluate the short-term ocular safety, feasibility, and exploratory functional signals associated with intravitreal adalimumab (ADA) in patients with retinitis pigmentosa (RP). Methods This prospective, single-arm pilot study included 21 patients with RP who received intravitreal adalimumab (2 mg/0.05 mL) at baseline, month 2, and month 4, with follow-up to month 6. The primary objective was to assess ocular safety and treatment feasibility. Exploratory functional outcomes included best-corrected visual acuity (BCVA, logarithm of the minimum angle of resolution (LogMAR)) and automated perimetry parameters (mean deviation (MD), pattern standard deviation (PSD), and Field Preservation Deviation Index (FPDI)). Structural assessment was performed using optical coherence tomography (OCT). Analyses compared baseline and month 6 outcomes using paired statistical methods. BCVA values were analyzed at the patient level as the mean of both eyes. Results All scheduled intravitreal injections were successfully completed, and no serious ocular adverse events were observed during follow-up. Mean BCVA showed no statistically significant change from baseline to month 6 (0.76 to 0.70 LogMAR; p = 0.115). Visual field parameters (MD, PSD, and FPDI) remained stable, with no statistically significant differences over time. OCT findings demonstrated advanced baseline structural alterations consistent with RP, without evidence of treatment-related anatomical deterioration or cystoid macular edema during follow-up. Flicker electroretinography (ERG) responses were measurable in a limited subset of patients and were analyzed descriptively, showing no consistent evidence of decline. Conclusions In this prospective pilot study, intravitreal adalimumab demonstrated a favorable short-term ocular safety profile and was feasible to administer in patients with retinitis pigmentosa. No significant functional or structural changes were observed over six months. These findings are hypothesis-generating and support the need for controlled studies to further evaluate the safety and potential role of tumor necrosis factor alpha (TNF-α) inhibition in inherited retinal degeneration.