The spleen tyrosine kinase inhibitor sovleplenib was assessed for efficacy and safety in the phase 3 ESLIM-01 trial (NCT05029635). Participants with primary ITP, previously treated with at least 1 therapy, were randomised 2:1 to sovleplenib or placebo (n=188). After 24 weeks, Dr Renchi Yang (Chinese Academy of Medical Sciences, China) and colleagues primarily assessed the durable response rate, defined as platelet counts ≥50*109 platelets/L on at least 4 out of 6 scheduled visits between weeks 14 and 24, not influenced by rescue therapy1.
Participants treated with sovleplenib achieved a durable response in 48.4 % of the cases, compared to 0% in the placebo arm (P<0.0001). The researchers also reported a higher overall response rate (at least 1 platelet count ≥50*109 platelets/L) in the sovleplenib arm during the study (70.6 % vs 16.1 %; P<0.0001).
In total, 25.4 % (experimental arm) and 24.2 % (control arm) experienced grade ≥3 treatment-emergent adverse events. Upper respiratory tract infection (28.6 %), COVID-19 infection (23.8 %), and increased blood lactate dehydrogenase (23.8 %) were common events in the sovleplenib arm. Finally, Dr Yang noted that physical functioning and fatigue had improved significantly in the sovleplenib arm.
In conclusion, the safety and efficacy results of the current phase 3 trial indicate that sovleplenib could be a potential treatment option for patients with primary ITP who have received at least 1 prior line of therapy.
Medical writing support was provided by Robert van den Heuvel.