It can affect both the larger and the smaller joints of the body. In humans, this includes the hands, wrists, feet, back, hip, and knee. In dogs, this includes the elbow, hip, stifle (knee), shoulder, and back. The disease is essentially one acquired from daily wear and tear of the joint; however, osteoarthritis can also occur as a result of injury. Osteoarthritis begins in the cartilage and eventually causes the two opposing bones to erode into each other. The condition starts with minor pain during physical activity, but soon the pain can be continuous and even occur while in a state of rest. The pain can be debilitating and prevent one from doing some activities. In dogs, this pain can significantly affect quality of life and may include difficulty going up and down stairs, struggling to get up after lying down, trouble walking on slick floors, being unable to hop in and out of vehicles, difficulty jumping on and off furniture, and behavioral changes (e.g., aggression, difficulty squatting to toilet). Osteoarthritis typically affects the weight-bearing joints, such as the back, knee and hip. Unlike rheumatoid arthritis, osteoarthritis is most commonly a disease of the elderly. The strongest predictor of osteoarthritis is increased age, likely due to the declining ability of chondrocytes to maintain the structural integrity of cartilage. More than 30 percent of women have some degree of osteoarthritis by age 65. Other risk factors for osteoarthritis include prior joint trauma, obesity, and a sedentary lifestyle.
No pharmaceutical companies were interested in selling the drug because hairy cell leukemia was an orphan disease, so Beutlers lab synthesised and packaged it and supplied it to the hospital pharmacy; the laboratory also developed a test to monitor blood levels. This was the first treatment that led to prolonged remission of hairy cell leukemia, which was previously untreatable. : 14–15 In February 1991, Scripps began a collaboration with Johnson & Johnson to bring intravenous cladribine to market, and by December of that year, Johnson & Johnson had filed a new drug application; cladribine was approved by the FDA in 1993 for hairy cell leukemia as an orphan drug, and was approved in Europe later that year. : 2 The subcutaneous formulation was developed in Switzerland in the early 1990s and it was commercialised by Lipomed GmbH in the 2000s. : 2

Safety profile of cladribine in hairy cell leukemia
Injectable cladribine suppresses the bodys ability to make new lymphocytes, natural killer cells, and neutrophils (called myelosuppression); data from hairy cell leukemia studies showed that about 70% of people taking the drug developed dangerously  low levels of white blood cells and about 30% developed infections and some of those progressed to septic shock; about 40% of people taking the drug had fewer red blood cells and became severely anaemic; and about 10% of people had too few platelets. At the dosage used to treat hairy cell leukemia in two clinical trials, 16% of people had rashes and 22% had nausea, the nausea generally did not lead to vomiting.