Parkinson’s Disease (PD) is a chronic and progressive movement disorder which primarily affects dopamine-producing (“dopaminergic”) neurons in a specific area of the brain called substantia nigra. These neurons are usually responsible for the control and coordination process, which during the neuron malfunction and death, is affected.
Early symptoms of Parkinson’s develop slowly and gradually varying from person to person. Tremors (mainly at rest), Bradykinesia, Limb rigidity, Gait, stooped posture and balancing problems are some of the symptoms people living with Parkinson’s experience.
Parkinson’s itself is not fatal, but the associated complications can be severe and life-harming.
Parkinson’s disease Epidemiology
According to the Parkinson’s disease foundation, more than 10 million people globally are living with Parkinson’s disease, and 60,000 Americans are diagnosed with Parkinson’s disease each year. According to the National Center for Health Statistics and Centers for Disease Control and Prevention, Parkinson’s disease is the 14th leading cause of death in the United States. The Parkinson’s incidence usually comprised of between 10 and 50 per 100,000 person-years and Parkinson’s prevalence is in between 100 and 300 per 100,000 population. The number of PD patients is expected to double by 2030 due to the general ageing of the people. T. Pringsheim et al. stated that PD is rare before the age of 50 and its incidence and prevalence both increases progressively after 60.
Parkinson’s prevalent female-to-male ratio is different. The high prevalence rate was found among males as compared to females in the United States. Chances of getting Parkinson’s disease are one and half times more in men than women.
Parkinson’s disease Therapeutic Market
The current Parkinson’s disease market is dominated by symptomatic drugs (for improving the motor features), supportive therapies, physiotherapy, diet therapy and standard physical and speech therapies.
Among symptomatic treatments, the market is subjugated by dopamine precursor substances such as levodopa, pramipexole, rotigotine and anticholinergic drugs such as trihexyphenidyl, amantadine, and newly approved Safinamide (Xadago) etc. Levodopa is the primary treatment for PD. However, its long-term use is limited by motor complications and drug-induced dyskinesia. Along with these medications, antidepressants are given to help control the non-motor symptoms of the disease. Some of the commercially available drugs for the Parkinson’s disease treatment are Cycloset, Parlodel (Bromocriptine Mesylate), Requip (ropinirole), Rytary, Azilect, Northera, Stalevo, Comtess/Comtan and others.
Parkinson’s disease Pipeline
With the rise in the geriatric population and rising male patients, Parkinson’s disease drug market is expected to witness significant growth. Several emerging pharmacotherapies for PD are in different stages of clinical development. These therapies include adenosine A2A receptor antagonists, glutamate receptor antagonists, monoamine oxidase inhibitors, anti-apoptotic agents, and antioxidants, such as coenzyme Q10, N-acetyl cysteine, and edaravone. Other emerging non-pharmacotherapies include viral vector gene therapy, microRNAs, transglutaminases, RTP801 (a stress-regulated protein), stem cells and glial-derived neurotrophic factor (GDNF).
These exciting treatments will change the Parkinson’s disease landscape dramatically in the short to medium term future.
Some of the key players involved in the development of PD are: Acorda Therapeutics, Biogen, Orion Pharmaceuticals, Reviva and Tools4Patient etc. Expected launch of emerging therapies, such as Acorda Therapeutics’ Pre-registration drug Inbrija (CVT-301, levodopa inhalation powder); Biogen’s Phase II clinical drug Cinpanemab (BIIB 054); Orion’s Phase II therapeutic candidate ODM 104, Reviva’s Phase II drug RP5063 (an investigational atypical antipsychotic) and Tools4Patient’s Phase I/II clinical candidate IPT803 and many more may change the treatment scenario of Parkinson’s disease in the upcoming years. Reviva’s PD drug candidate is also under investigation in multiple indications including Schizophrenia (Phase III); Bipolar Disorder, Major Depressive Disorder, Alzheimer’s, ADHD/ADD in mid stage development; Depression TRD, Obesity and Insomnia under pre-clinical development.
Parkinson’s remains a mystery
Although a number of genes have been implicated in the genesis of PD, the cause in the majority of patients is still unclear. A lack of treatment options for changing the trajectory of disease progression, in combination with an increasing elderly population, portends a rising economic burden on PD patients.
Thus, the current Parkinson’s disease Pharmacological therapies alleviate the motor symptoms of the disease and are particularly effective only in the early stages of the disease. However, over the past decade, considerable progress has been made in the treatment of PD such as identification of new therapeutic targets through genetic research and understanding the common mutations that contribute to PD etc.
Although, there is no cure for Parkinson’s. But with the advent of good reimbursement policies, there soon will be better treatments and therapies to relieve the symptoms.