Eltrombopag, a Potential New Treatment for ITP Save

A pilot trial has shown a thrombopoietin receptor agonist, eltrombopag (Promacta), to be effective in connective tissue disease-related (CTD),  refractory immune thrombocytopenia (ITP).

An observational study of Eltrombopag in 52 CTD-ITP patients who were unresponsive to or intolerant of conventional medications. Eltrombopag was given orally at 25–75 mg/qd and adjusted to tolerance and efficacy. Patients were followed monthly for labs, clinical outcomes, therapeutic response, relapse, and adverse events. Complete remission (CR) was defined as a platelet count ≥ 100 × 109/L; and partial remission (PR) was defined as a platelet count 50–100 × 109/L. 

The study cohort included the following CTD patients: 28 with SLE, 14 with Sjögren’s syndrome, 5 with MCTD, 2 with UCTD, and 1 each with RA, antiphospholipid syndrome, and ANCA vasculitis. ANA positivity was seen in 79%, 83% at least 1 comorbidity (renal 29%) and the median baseline platelet count was 13 × 10⁹/L (range: 1-30K).

 hs. With respect to the serological profiles, antinuclear antibodies (ANAs) were the most prevalent and were detected in 41 patients (78.8%). Other autoantibodies observed included anti-SSA in 55.8% of patients, anti-SSB in 15.4%, anti-dsDNA in 5.8%, anti-Ro 52 in 55.8%, anti-Sm in 9.6%, anti-CENP-B in 5.8%, and ANCA in 1.9% of patients. The majority of patients (43, 82.7%) had at least one comorbidity. Renal insufficiency was the most frequent (29%). All were treated with a variety of DMARDs or biologics or IVIG.

With a median of 6 months followup, 36 (90%) patients achieved durable overall remission. The remission rates were 67.5% by 1 month, 87.5% at month 2, 97.5% at month 3, and 95% at month 6. 

Platelet counts increased significantly, reaching a median of 50 × 10⁹/L within 2 weeks (p = 0.003). 

Patients with SLE and pSS patients had significant improvement in disease activity (p = 0.016), with glucocorticoid tapering (p = 0.004). One patient had no response, four relapsed, and fifteen (28.8%) experienced clinically relevant adverse events. 

Autoimmune patients with ITP patients, may benefit from Eltrombopag with laboratory and clinical improvement, and a steroid-sparing effect. In the USA, the drug is currently FDA approved for use in adult and children with immune thrombocytopenia (ITP) nonresponsive to corticosteroids, immunoglobulins, or splenectomy, especially those with a significant risk for bleeding.