AYVAKYT-targeted inhibition of KIT D816V demonstrated sustained clinical benefits across primary and key secondary endpoints in ISM1–3
In PIONEER, symptom severity in ISM was assessed using ISM-SAF TSS, a validated clinical endpoint2
Primary endpoint
AYVAKYT + BSC showed a statistically significant improvement in ISM-SAF TSS vs placebo at Week 24 (P=0.003)1,2
MEAN CHANGE IN ISM-SAF TSS AT WEEK 241
*For AYVAKYT-treated patients who rolled over into the open-label extension of PIONEER (Part 3).
**Placebo patients were allowed to move into an open-label ongoing AYVAKYT crossover arm, with TSS data available from Week 24 onwards.
Patients in the AYVAKYT + BSC arm continued to report improvements in TSS over time, with a mean TSS reduction of -19.0 from baseline at Week 963
Key secondary endpoints
AYVAKYT + BSC demonstrated statistically significant clinical improvements vs placebo + BSC, using ≥30% and ≥50% TSS thresholds1
PROPORTION OF PATIENTS ACHIEVING ≥30% REDUCTION IN ISM-SAF TSS THROUGH 24 WEEKS1,2
PROPORTION OF PATIENTS ACHIEVING ≥50% REDUCTION IN ISM-SAF TSS THROUGH 24 WEEKS1,2
Figures adapted from Gotlib et al. 2023.
A 30% reduction in TSS was selected as a valid and conservative threshold to represent the clinically important response or improvement at the individual level4
Key secondary endpoints
AYVAKYT + BSC delivered significant improvements in objective mast cell measures vs placebo + BSC at Week 241,2
†P<0.0001.
ITT analysis: For patients with high-dose steroid use within 7 days before Week 24, or greater than 14 consecutive days at any point from baseline to Week 24, the Week 24 score was set to missing.
Learn about the safety of AYVAKYT in the PIONEER trial
PIONEER Safety DataBSC=best supportive care; CI=confidence interval; ISM-SAF=Indolent Systemic Mastocytosis-Symptom Assessment Form; ITT=intent[ion] to treat; TSS=total symptom score; VAF=variant allele fraction
