Psoriasis
Psoriasis is a chronic skin condition that leads to itchy, scaly patches, typically appearing on the knees, elbows, trunk, and scalp. It is a common, long-term condition with no cure. Psoriasis can be painful, disrupt sleep, and make it difficult to focus. The disease tends to follow a cyclical pattern, flaring up for weeks or months before subsiding. In individuals with a genetic predisposition, common triggers include infections, skin injuries (such as cuts or burns), and certain medications. While there is no cure, treatments are available to help manage symptoms.
Symptoms:
Common signs and symptoms of psoriasis include:
• A patchy rash that can vary significantly in appearance from person to person, ranging from small, dandruff-like scales to larger outbreaks covering much of the body.
• Rashes that differ in color, often appearing as shades of purple with gray scales on brown or Black skin, and as pink or red with silver scales on white skin.
• Small, scaling spots, which are most commonly seen in children.
• Dry, cracked skin that may bleed.
• Itching, burning, or soreness.
• Cyclical flare-ups, where rashes worsen for weeks or months before improving
Types
There are several types of psoriasis, each with its own unique signs and symptoms:
Plaque Psoriasis
Plaque psoriasis, the most common type, causes dry, itchy, raised patches of skin covered in scales. These patches, which can range from few to many, typically appear on the elbows, knees, lower back, and scalp. The color of the patches varies by skin tone, and on brown or Black skin, healing may leave temporary color changes.
Nail Psoriasis
Psoriasis can also impact the nails, leading to pitting, abnormal growth, and discoloration. In some cases, nails may loosen and separate from the nail bed (onycholysis), and in severe cases, they may crumble.
Guttate Psoriasis
This type primarily affects children and young adults and is often triggered by a bacterial infection like strep throat. It is marked by small, drop-shaped, scaling spots that appear on the trunk, arms, or legs.
Inverse Psoriasis
Inverse psoriasis usually affects skin folds, such as in the groin, buttocks, and under the breasts. It causes smooth, inflamed patches that worsen with friction and sweating. Fungal infections can trigger this form of psoriasis.
Pustular Psoriasis
Pustular psoriasis, a rare form of the condition, causes distinct, pusfilled blisters. It can affect large areas of the body or appear in smaller patches on the palms and soles of the feet.
Erythrodermic Psoriasis
Erythrodermic psoriasis, the rarest form, causes widespread inflammation and peeling of the skin, often accompanied by intense itching or burning. It can be either acute (short-term) or chronic (long-term)
Drug Class Distribution and Development Phases
According to the AdisInsight database, the following is a comprehensive overview of drugs grouped into eight main drug classes, along with their respective development phases.
Table 21- Drug Distribution Breakdown for Psoriasis
According to the graph, small molecules are at the forefront of development, with eight drugs in late-stage clinical development, forty-eight in early-stage clinical development, and two drugs in the registered phase.
Drug development phases Vs drug class
Fig 16: Development phases of drugs versus drug class distribution
Analysis of Development Phases and Routes of Administration
As depicted in the graph, oral route of administration is in the lead, with thirty-nine drugs in early-stage clinical development, seven drugs in late-stage development and one in the registered phase.
Drug development phases Vs RoA
Fig 17: Development phases of drugs versus RoA distribution
Overview of Development Stages and Formulations
Based on data from the AdisInsight database, injection formulations are leading the development pipeline, with fourteen drugs in early-stage clinical trials, thirteen in late-stage development, five in the preregistration phase, and twelve in the registered phase.
Drug development phases Vs formulation of drugs
Fig 18: Development phases of drugs versus formulation
Drugs Available for Licensing
As demand for psoriasis treatments continues to rise, many pharmaceutical companies are generating significant revenue by acquiring psoriasis-related drugs. For instance, in 2019, Amgen acquired the global rights to Otezla from Celgene Corporation. Otezla is an oral, non-biologic treatment for moderate-to-severe plaque psoriasis and psoriatic arthritis. However, Otezla sales decreased by 9% year-over-year, totaling $544 million in the second quarter of 2024. According to the AdisInsight database, the following psoriasis drugs are available for licensing: seven in early-stage clinical development, five in late-stage clinical development, one in the preregistration phase, and eighteen in the preclinical or research phase.
Table 22- Drugs available for licensing for Psoriasis