HSPG2 and Parkinson disease: OPC 50 mg was also significantly more effective than PLC in increasing total ON-time from baseline in the majority of subgroup analyses (p < 0.05), excluding the following: patients with duration of PD ≥8 years (p = 0.0541), patients with onset of motor fluctuations >2 years previously (p = 0.0527), patients who received ≥6 L-DOPA intakes (p = 0.0767), patients with L-DOPA treatment duration ≥7 years (p = 0.4855), and patients with L-DOPA treatment duration ≥8 years (p = 0.4902) (Supplementary Table 3).