Doptelet provided a rapid and durable platelet response over time1†
Patients on Doptelet reached target platelet counts of 50,000/μL for a median of 12.4 cumulative weeks.1
Median Platelet Count (Q1, Q3)2,3
P<0.0001 vs placebo
Core Study: Efficacy was evaluated in a 6-month, multicenter, randomized, double-blind, placebo-controlled Phase 3 study. Patients had received one or more prior chronic ITP therapies and had average screening and baseline platelet counts of <30×109/L. Forty-nine patients were randomized (2:1) to receive either Doptelet (n=32) or placebo (n=17).1
- The primary efficacy endpoint was the cumulative number of weeks of platelet response, defined as a platelet count ≥50×109/L in the absence of rescue therapy, over 6 months of once-daily treatment in adults with chronic ITP. Doptelet-treated patients had a median duration of 12.4 cumulative weeks vs 0 weeks for placebo1
- A secondary efficacy endpoint was the proportion of patients with a platelet response (platelet counts ≥50×109/L) at Day 8. 66% (n=21/32) of Doptelet-treated patients had platelet counts of ≥50,000/μL at Day 8 compared to placebo (n=0/17)1
Open-label extension: Patients could enter the open-label extension phase if they completed the 6-month core study, or if they experienced a lack of efficacy during that period. In the extension phase, all patients received titrated Doptelet once daily. Thirty-nine patients (24 Doptelet and 15 placebo) entered the 90-week maintenance period of the extension phase, in which Doptelet dose titration and downward titration of concomitant ITP medications were allowed. At the end of the extension phase, a 4-week, dose-tapering period was followed by a 30-day follow-up after the last dose of Doptelet.2,4
- The primary endpoint of the extension study was to assess the long-term safety and efficacy of treatment with Doptelet by measuring platelet response rate, bleeding, and the use of rescue therapy2
- Exploratory endpoints included the percentage of patients who achieved platelet counts ≥50,000/μL or ≥100,000/μL at any time during the core study and its extension phase. These endpoints were reported in an integrated analysis of the Phase 3 core study and extension phase data. In an integrated analysis of the core study and its extension phase, 93.8% of patients initially randomized to Doptelet and who continued to be treated with Doptelet during the extension phase achieved a platelet count of ≥50,000/μL at any time, compared to 64.7% of placebo patients who rolled over to Doptelet4,5
*Throughout the core study and extension phase, 72.3% of patients were exposed to avatrombopag for at least 32 weeks. In the open-label extension phase for those patients continuing Doptelet treatment, a response was achieved at 44.2% of visits.2,4
†ASH guidelines define a durable response as platelet count ≥30x109/L and at least doubling of the baseline count at 6 months.2,6
‡Target platelet count window in pivotal trial was ≥50x109/L to ≤150x109/L.2
Curious about Doptelet’s safety profile?
Learn more about Doptelet’s adverse reactions from clinical trials.
- DOPTELET (avatrombopag) [prescribing information]. Durham, NC: AkaRx, Inc; 2021.
- Jurczak W, Chojnowski K, Mayer J, et al. Phase 3 randomised study of avatrombopag, a novel thrombopoietin receptor agonist for the treatment of chronic immune thrombocytopenia. Br J Haematol. 2018;183(3):479-490.
- Data on File. Summary of Local Platelet Count. 2014: Sobi, Inc.
- Al-Samkari H, Aggarwal K, Vredenburg M, Tian W, Allen LF. Long-term response rates in patients with chronic immune thrombocytopenia treated with avatrombopag: additional analyses from a phase 3 study and its extension phase. Blood. 2019;134(suppl 1):2356.
- Nagalla S, Vredenburg M, Tian W, Allen LF. Platelet response to avatrombopag in patients with chronic immune thrombocytopenia: additional analyses from a phase 3 study and its extension. Blood. 2019;134(suppl 1):1071.
- Neunert C, Terrell DR, Arnold DM, et al. American Society of Hematology 2019 guidelines for immune thrombocytopenia. Blood Adv. 2019;3(23):3829-3866.