Lupus erythematosus is an autoimmune inflammatory connective tissue disease. From the perspective of pathogenesis, the mainstream view is that genetic factors, environmental factors, estrogen levels and other factors interact to cause excessive proliferation of B cells in patients, resulting in a large number of autoantibodies.
The antibody binds to the corresponding autoantigen in the body to form a corresponding immune complex, which is deposited on the skin, joints, small blood vessels, glomeruli and the like.
Then, with the participation of complement, cause acute and chronic inflammation and tissue necrosis. Or the antibody directly interacts with the tissue cell antigen, causing cell destruction, resulting in multiple system damage of the body.
Systemic lupus erythematosus (SLE) is the most common type of lupus erythematosus (about 70%) and the most serious, with a variety of clinical manifestations, including large areas of red rash, fever, pain, kidney damage, Respiratory and nervous system involvement and so on. SLE is more common in young women, the age of onset is 20 to 40 years old, and the traditional treatment has a relatively poor prognosis. With the improvement of treatment technology, the 10-year survival rate has gradually increased from less than 50% to 60% to 70%, but good. Therapeutic drugs are still limited and clinical needs are far from being met.
Most of SLE’s traditional treatments are non-selective immunosuppressants used to relieve inflammation, such as aspirin, cyclophosphamide, glucocorticoids (prednisone, hydrocortisone, betamethasone), etc. There is also hydroxychloroquine approved by the FDA in April 1955. Until 2011/3/9, the injectable belimumab (trade name Benlysta) developed by GSK was approved by the FDA and became the first new SLE drug approved by the FDA for more than 50 years. It also opened a new chapter in clinical treatment of SLE.
In fact, since the approval of belimumab, no other drugs have been approved for the treatment of systemic lupus erythematosus since 2011. Belimumab is arguably the first new drug for lupus in 60 years.
2019/7/2, GSK’s application for injection for belimumab in China (JXSS1800005/6) was approved by the National Drug Administration (NMPA), meaning that this innovative SLE new drug will soon be available in China.
Belimumab is a specific inhibitor of first-class B lymphocyte stimulating factor (BLyS, also known as BAFF), which has a higher affinity for soluble BLyS in serum, thereby blocking the binding of receptors on BLyS and B cells, inhibiting B cell proliferation and differentiation of B cells into plasma cells, thereby reducing autoantibodies produced by B cells in serum, to achieve the purpose of treating SLE.
Belimumab is also the only BLyS antibody currently on the market. It is currently only approved for SLE. Global sales have grown steadily, reaching 473 million pounds in 2018.
Belimumab was first approved by the FDA in 2011/3/9 for autoantibody-positive adult SLE patients. At the time, an intravenous injection was administered at a dose of 10 mg/kg, and the first three doses were administered once every two weeks. Once every 4 weeks, each administration time is 1 hour.
2017/7/20, Belimumab’s subcutaneous injection form is FDA-approved for active, autoantibody-positive systemic lupus erythematosus (SLE) adults who are receiving standard treatment at a dose of 200 mg once a week. The administration time is short, and the patient can self-administer the drug, which improves the convenience.
2019/4/27, belimumab expands to the applicable population and is approved by the FDA for use in pediatric SLE patients over 5 years of age. It is the first US drug approved for SLE in children.
Belimumab can significantly reduce the 52-week systemic lupus erythematosus disease response index in patients with SLE and reduce disease recurrence. At the 2017 European Society of Rheumatology (EULAR) annual meeting, GSK published a 10-year clinical study of belimumab in the treatment of active SLE. A total of 298 patients were enrolled in the long-term ongoing study, and in the 10th year, 131 (44%) patients were still under investigation. The results showed that the proportion of patients who achieved remission by belimumab treatment gradually increased over time, with a total response rate of 65.2% in the 10th year (n=126). For patients with a prednisone dose above 7.5 mg/d at baseline, 32.6% (14/43) reduced dose to ≤7.5 mg/d at 10 years; prednisone dose ≤7.5 mg/d for baseline In the 10th year, 9.5% (9/95) dose increased to over 7.5 mg/d.
There is no accurate data on the number of patients with lupus erythematosus in China. A large sample (>30,000) survey showed that the prevalence of systemic lupus erythematosus in China was 70/100,000, and among women, it was 113/100,000. Belimumab can improve the patient’s symptoms, reduce the recurrence of the disease, and contribute to the long-term prognosis of the patient. Belimumab was approved for approval in China by priority review and will also provide new treatment options for Chinese SLE patients. From the approval process of this drug in China, we can also see that NMPA attaches great importance to this urgently needed new drug, from “NMPA began administrative approval” to “End of approval, pending certification” only one day.