What Is Telitacicept?
Telitacicept is an FDA-approved medication for **pediatric ocular myasthenia gravis (OMG)**. This approval is anticipated in May 2025. Additionally, Telitacicept was conditionally approved in China in March 2021 for **Systemic Lupus Erythematosus (SLE)**.
Telitacicept is a biologic agent that targets specific immune cells called B lymphocytes. In autoimmune diseases like SLE and myasthenia gravis, B lymphocytes can become abnormally activated, leading to inflammation and tissue damage. By targeting these cells, Telitacicept aims to reduce their overactivity and help manage disease symptoms.
Currently, Telitacicept is being investigated in clinical trials for various other conditions, including IgA Nephropathy and other autoimmune diseases. A total of **46 trials** have been conducted or are ongoing, with **17 trials** currently recruiting participants. These studies have collectively enrolled **4,408 participants** since the first trial began on May 27, 2021.
Uses and Conditions Under Study
Telitacicept is being studied for its potential to treat several autoimmune conditions where abnormal B-cell activity plays a role. Clinical trials for Telitacicept are exploring its use in:
- Systemic Lupus Erythematosus (SLE) and Lupus Nephritis: SLE is a systemic autoimmune disease characterized by abnormal activation of B lymphocytes, which can lead to various adverse consequences. Lupus nephritis is a serious kidney complication of SLE. Telitacicept, as a B-cell targeting agent, is being investigated to reduce this abnormal B-cell activity and improve outcomes. There are **9 trials** specifically for Systemic Lupus Erythematosus, **2 trials** for Systemic Lupus Erythematosus (SLE), and **2 trials** for Lupus Nephritis.
- IgA Nephropathy (IgAN): This is a kidney disease caused by deposits of immunoglobulin A (IgA) in the kidneys. Telitacicept is being studied to see if it can help manage this condition by affecting immune responses. There are **3 trials** for IgA Nephropathy (IgAN) and **2 trials** for IgA Nephropathy.
- Myasthenia Gravis (MG): MG is an autoimmune disease where autoantibodies disrupt nerve-to-muscle signal transmission, causing muscle weakness. Telitacicept is being investigated to target the B cells responsible for producing these autoantibodies. There are **2 trials** for Myasthenia Gravis.
- Other Autoimmune and Connective Tissue Diseases: Telitacicept is also under investigation for a broader range of autoimmune diseases and conditions affecting connective tissues, including CTD-ILD (Connective Tissue Disease-associated Interstitial Lung Disease). There are **2 trials** for Autoimmune Diseases, **1 trial** for Connective Tissue Diseases, and **1 trial** for CTD-ILD.
- General Research: Some trials are focused on understanding the drug itself, such as its pharmacokinetics and pharmacodynamics, under the condition "Telitacicept." There are **4 trials** in this category.
Dosing
Telitacicept is administered as a subcutaneous injection. Various strengths and dosing regimens have been studied in clinical trials, often in combination with existing medications.
Commonly studied strengths include **80 mg**, **160 mg**, and **240 mg**. For example, one regimen involves adding **Telitacicept 240 mg** administered via subcutaneous injection once a week for a total of 12 weeks, on top of original foundational medication.
In pediatric patients with ocular myasthenia gravis (OMG), the dose is adjusted based on body weight:
- **160 mg** per dose for those weighing **40 kg or more**.
- **80 mg** per dose for those weighing between **20 kg and less than 40 kg**.
- For patients weighing **less than 20 kg** or aged **less than 5 years**, a gradual dosing approach is used.
Telitacicept has been studied in both pre-filled injection pens and freeze-dried powder for injection, both at **80 mg** strength.
Side Effects
The most common side effect reported in clinical trials for Telitacicept was upper respiratory tract infection. In a study involving patients with systemic lupus erythematosus (SLE), 29.7% of patients taking Telitacicept experienced an upper respiratory tract infection, compared to 24.4% of patients on placebo.
Other common side effects observed in Telitacicept-treated patients, compared to placebo, included:
- Urinary tract infection: 11.6% vs. 9.4%
- Herpes zoster (shingles): 4.1% vs. 1.3%
- Leukopenia (low white blood cell count): 3.4% vs. 0.7%
- Diarrhea: 3.1% vs. 2.7%
- Injection site reaction: 2.7% vs. 1.0%
- Hypersensitivity reactions: 2.0% vs. 0.7%
In a separate open-label study involving 10 dialysis patients with hyperphosphatemia, specific side effects related to this population were observed. These included AV fistula complication in 20% of patients, hyperkalemia (high potassium levels) in 20%, and hypophosphatemia (low phosphate levels) in 10%.
Clinical Trial Results
Systemic Lupus Erythematosus (SLE)
In a Phase 3 clinical trial (NCT03244552) involving 293 patients with active SLE treated with Telitacicept 160mg and 299 patients on placebo, Telitacicept demonstrated significant improvements. The primary goal of the study, achieving an SRI-4 response (a measure of disease activity improvement) at Week 52, was met by 44.3% of patients on Telitacicept, compared to 33.7% of patients on placebo. This represents a statistically significant difference.
Key secondary outcomes also showed positive results for Telitacicept:
- 50.9% of patients on Telitacicept experienced a reduction of 4 points or more in their SLEDAI-2K score (another measure of disease activity), compared to 40.5% on placebo.
- Patients treated with Telitacicept were more likely to reduce their daily glucocorticoid (steroid) dosage to 7.5 mg or less, with 35.5% achieving this, compared to 24.1% on placebo.
- Telitacicept also significantly extended the time to the first disease flare and reduced the incidence of serious flares (4.1% vs. 8.0% on placebo).
- Levels of anti-dsDNA antibodies, a marker of SLE activity, were significantly reduced in the Telitacicept group (by 119.5 IU/mL) compared to the placebo group (by 1.8 IU/mL).
IgA Nephropathy
A Phase 2 trial (NCT04917927) in patients with IgA nephropathy (125 patients on Telitacicept, 62 on placebo) investigated the effect of Telitacicept on proteinuria (protein in the urine). At Week 24, patients treated with Telitacicept experienced a mean reduction in proteinuria of 25.8% from baseline, while those on placebo had a mean reduction of 1.7%. This significant difference indicates an improvement in kidney function markers.
Additionally, Telitacicept led to substantial reductions in serum IgA levels (33.3% reduction vs. 0.2% on placebo) and IgG levels (12.3% reduction vs. 0.1% on placebo), which are relevant to the disease mechanism of IgA nephropathy.
Myasthenia Gravis
In a Phase 2 study (NCT04849312) involving 130 patients with generalized myasthenia gravis treated with Telitacicept and 65 patients on placebo, Telitacicept significantly improved disease symptoms. The primary endpoint, the change in the Myasthenia Gravis Activities of Daily Living (MG-ADL) score from baseline at Week 24, showed a mean reduction of 3.5 points for Telitacicept-treated patients, compared to a 2.0-point reduction for those on placebo. A lower score indicates fewer symptoms.
Further improvements were seen in secondary endpoints:
- The Quantitative Myasthenia Gravis (QMG) score, another measure of disease severity, decreased by 3.8 points in the Telitacicept group versus 2.0 points in the placebo group.
- 53.1% of patients on Telitacicept achieved an MG-ADL response (a reduction of at least 3 points), compared to 35.4% on placebo.
- Serum IgG levels were reduced by 22.0% and IgA levels by 20.0% in the Telitacicept group, compared to minimal changes in the placebo group.
Hyperphosphatemia in Dialysis Patients
An open-label study (NCT04313274) in 10 dialysis patients with hyperphosphatemia (high phosphate levels) evaluated the effect of Telitacicept. After 4 weeks, Telitacicept reduced mean serum phosphate levels by 1.4 mg/dL, from an average of 6.7 mg/dL at baseline to 5.3 mg/dL. Importantly, 70% of these patients achieved the target phosphate level of less than 5.5 mg/dL. The study also observed reductions in serum IgA (49.3%), IgG (29.8%), and IgM (42.0%) levels.
Currently Recruiting Trials
Telitacicept is currently being investigated in numerous clinical trials for a variety of autoimmune and kidney-related conditions. These studies are actively seeking participants to help evaluate the drug's safety and effectiveness.
For individuals with Myasthenia Gravis, two Phase 3 studies are underway. One trial, NCT07249632, is focused on Ocular Myasthenia Gravis (OMG), aiming to enroll approximately 120 subjects aged 12 to 80 years. Another Phase 3 study, NCT06456580, known as UPSTREAM MG, is evaluating Telitacicept for Generalized Myasthenia Gravis, with an enrollment target of 180 participants.
Several trials are exploring Telitacicept for kidney diseases. A Phase 2 study, NCT07522099, sponsored by ADARx Pharmaceuticals, Inc., is assessing ADX-038 (Telitacicept) in Chinese adults with Immunoglobulin A Nephropathy (IgAN), Complement 3 Glomerulopathy (C3G), and IC-MPGN, targeting 30 participants. Another study, NCT06654596, is evaluating Telitacicept's efficacy and safety in IgAN patients at high risk of progression, aiming for 118 participants. For pediatric patients, a Phase 3 study, NCT06125405, is investigating Telitacicept in children with frequently relapsing or steroid-dependent nephrotic syndrome, with a target of 20 participants. Additionally, a Phase 2 study, NCT05680480, is evaluating Telitacicept in adult patients with active Lupus Nephritis, planning to enroll 120 individuals.
Systemic Lupus Erythematosus (SLE) and related conditions are also a focus. A Phase 2 trial, NCT07340463, is comparing Telitacicept-based induction therapy with mycophenolate mofetil in proliferative Lupus Nephritis patients, enrolling 50 participants. A Phase 4 study, NCT07077486, is comparing Telitacicept to cyclophosphamide for lupus-related interstitial lung disease in 100 patients. Another study, NCT06394063, is investigating low-dose Telitacicept for flare prevention in SLE patients with low disease activity, aiming for 176 participants.
Other conditions under investigation include Primary Sjögren's Disease in a Phase 3 study, NCT07404865, targeting 250 participants. For Systemic Sclerosis, a Phase 2 study, NCT06375005, is evaluating Telitacicept in early diffuse cutaneous systemic sclerosis, enrolling 38 adults, and a Phase 4 study, NCT06546540, is also assessing Telitacicept's safety and efficacy in Systemic Sclerosis with 20 participants. A trial, NCT06979271, is exploring Telitacicept combined with tofacitinib for refractory Rheumatoid Arthritis in 20 patients. Connective tissue disease-associated thrombocytopenia is being studied in a Phase 2 trial, NCT05998759, with an enrollment goal of 296. Finally, two Phase 4 studies are focusing on ANCA-associated vasculitis: NCT05962840 is combining Telitacicept with Rituximab for induction, and NCT05965284 is evaluating Telitacicept for remission maintenance, both aiming for 40 participants. A Phase 1 study, NCT06549959, is also investigating the pharmacokinetics of Telitacicept in 248 healthy Chinese subjects.
Where to Participate
Clinical trials for Telitacicept are being conducted across a wide geographic area, with study sites located in 35 facilities across 37 cities and 14 states. This broad reach aims to make participation accessible to a diverse patient population.
Top locations with recruiting sites include:
- Houston, Texas (2 sites)
- Flagstaff, Arizona (1 site)
- Glendale, Arizona (1 site)
- Phoenix, Arizona (1 site)
- Tucson, Arizona (1 site)
- Beverly Hills, California (1 site)
- Los Angeles, California (1 site)
- Orange, California (1 site)
- San Francisco, California (1 site)
- Boca Raton, Florida (1 site)
Eligibility criteria for these studies are broad, welcoming participants aged 2 to 85 years, of all genders. Many trials also include provisions for children, and some studies are specifically recruiting healthy volunteers to help understand the drug's basic properties.
Development Timeline
The journey of Telitacicept in clinical development began on May 27, 2021, with the latest trial starting on April 13, 2026. Since its inception, a robust program of 46 clinical trials has been initiated, collectively aiming to enroll over 4,400 participants.
Initial investigations into Telitacicept focused on conditions such as IBS-C and hyperphosphatemia. However, the development pipeline quickly expanded, reflecting the drug's potential across a broader spectrum of autoimmune and inflammatory diseases. Key sponsors like RemeGen Co., Ltd., Vor Biopharma, and the Chinese SLE Treatment And Research Group have been instrumental in driving this expansion.
The drug's development has progressed through various phases, with a significant number of studies reaching advanced stages. There are 13 trials in Phase 3, 11 in Phase 2, and 9 in Phase 4, indicating a mature and active research program. This progression demonstrates a commitment to thoroughly evaluating Telitacicept's efficacy and safety.
The range of conditions under study has grown considerably to include IgA Nephropathy (IgAN), Myasthenia Gravis (both ocular and generalized forms), Lupus Nephritis, Systemic Lupus Erythematosus (SLE), Connective Tissue Diseases, Systemic Sclerosis, Rheumatoid Arthritis, and ANCA-associated Vasculitis. This broad exploration highlights Telitacicept's potential as a treatment option for multiple complex autoimmune and kidney disorders.