Table 3 Small molecules being tested in phase I, II, or III clinical studies to treat PD. Information depends on clinical trials. gov (https://clinicaltrials.gov) trial statuses as of 2022 (ongoing, updated, or discontinued) (Masato et al. 2019; Millichap et al. 2021; 2021; Merkow et al. 2020; Merchant et al. 2019; Ivanova 2020; Mullin et al. 2020; Parker et al. 2020; Barker 2019; Ghosh et al. 2021)
Therapeutic strategy | Classification | Name of compound | PD subjects | Trial status | Reasons for discontinuation | Sponsor | Clinical trial numbers and references |
|---|---|---|---|---|---|---|---|
Convalescing plasma therapy | Infusion of young plasma | Infusion of young plasma | Moderate stage of PD | Phase I | – | Stanford University | NCT02968433 (Trist et al. 2019) |
Cell-based therapy | Injection of cultured human retinal pigment epithelial cells within both hemispheres | Spheramine/ BAY86-5280 | Advanced stage of PD | Phase II discontinued | The trial was completed, and only the follow-up phase was discontinued after 12 years | Bayer | NCT00206687 (Nakamura et al. 2021) |
Gene therapy | Small molecular glucocerebrosidase (GBA) gene mutating therapy | GZ/SAR402671 | Early stage of PD | Phase II discontinued | Terminated due to not meeting the primary and secondary endpoints | Genzyme | NCT02906020 (Jiménez-Gómez et al. 2023) |
Serotonin receptors agonists or antagonists | Small molecular selective 5-HT1A agonist and D2 antagonist | Sarizotan | Idiopathic PD | Phase III | – | EMD Serono | NCT00105508 (Choudhury et al. 2022) |
Anti-apoptotic drugs | Small molecular synthetic tetracycline derivative | Minocycline | Early stage untreated | PD Phase II | – | University of Rochester | NCT00063193 (Bouchez and Devin 2019) |
Kinase inhibitor | Small molecular Semisynthetic inhibitor of the mixed lineage kinase family | CEP-1347 (KT7515)] | Early stage of PD | PD phase II/III discontinued | Terminated due to insufficient efficacy | Cephalon | NCT00040404 (Nunes and Laranjinha 2021) |
Gene therapy | Surgical infusion of AAV-GAD into the subthalamic nucleus | Glutamic acid decarboxylase (GAD) gene therapy | Advanced stage of PD | Phase-I | – | Neurologix, Inc | NCT00195143(Braidy et al. 2019) |
Cell-based therapy | Embryonic dopamine cell implant | Embryonic dopamine cell implant surgery | Idiopathic PD | Phase-III | – | University of Colorado, Denver | NCT00038116(Masato et al. 2019) |
Dopamine receptor agonists | Small molecular dopamine D1 partial agonist | PF-06669571 | Idiopathic PD | Phase-I | – | Pfizer | NCT02565628(Millichap et al. 2021) |
Gene therapy | AAV2-neurturin gene therapy | CERE-120 | Idiopathic PD | Phase-II | – | Sangamo Therapeutics (Ceregene | NCT00400634(Clinical Research. 2021) |