Sarah Gheuens
Analyst · Citi
Thank you, Tsveta. Next slide, please. We continue to advance a robust pipeline anchored by our PK activation franchise and complemented by differentiated early-stage clinical programs. In the first quarter, we announced plans to initiate two pediatric mitapivat trials in thalassemia, ENERGIZE-KidsT in transfusion-dependent patients and ENERGIZE-Kids in non-transfusion-dependent patients. We look forward to the potential to expand access to this transformative medicine into pediatric populations. Finally, we are looking ahead to upcoming second quarter readouts, including Phase IIb top line data for tebapivat, our next-generation PK activator in low-risk MDS. This study evaluates 10-, 15- and 20-milligram dose levels across a broad patient population with eight consecutive weeks of transfusion independence as the primary endpoint. While this represents a higher risk opportunity, we see meaningful potential for an oral therapy in this setting. Please move to the next slide. In the first quarter, we completed a pre-sNDA meeting with the FDA and aligned on a path towards U.S. accelerated approval for mitapivat in sickle cell disease. Since that meeting, we've had a series of informal and formal engagements to gain official alignment on the confirmatory clinical trial required under this pathway. We are pleased with the progression of these discussions and now expect we will file an sNDA in the second quarter. We look forward to sharing additional data from the RISE UP Phase III trial at an upcoming medical congress, including analyses that informed our selection of the confirmatory clinical trial's primary endpoint. Taking a step back, as we consider development of the confirmatory trial design, we emphasized operational feasibility, including enrollment time lines and time to completion while looking to maximize probability of success and the potential to further enhance the mitapivat label should U.S. full approval be granted upon results of confirmatory trial. Next slide, please. In parallel, we are advancing tebapivat, our next-generation PK activator in Phase II studies across low-risk MDS and sickle cell disease. Tebapivat was intentionally designed to go beyond first-generation PK activators. It is structurally differentiated with potent dual activation of PKR and PKM2 and PK and PD properties that support once-daily dosing without the need for a taper. Importantly, the early clinical data reflect these design features. In sickle cell disease, tebapivat demonstrated a long half-life of approximately 87 to 93 hours, dose-dependent reductions in 2,3-DPG and increases in ATP and pharmacodynamic effects that remain durable for up to four weeks after the last dose. We also observed a mean hemoglobin increase of 1.9 grams per deciliter at the 5-milligram once daily dose. Beyond red blood cell metabolism, tebapivat shows broader biological activity driven by PKM2 activation. In preclinical models, this translated into antifibrotic effects, including reduced glomerular injury and myofibroblast signaling, supporting the potential for disease-relevant activity beyond mature red blood cells. In low-risk MDS, we observed early clinical signals, including transfusion independence in the low transfusion burden cohort. However, we observed 60% lower drug exposure relative to healthy volunteers, which prompted investigation at higher doses. The ongoing Phase IIb study, which is evaluating higher doses in a broader lower-risk MDS population will test the hypothesis that deeper PKR and PKM2 activation may extend biological activity into erythroid maturation in the bone marrow. In sickle cell disease, our Phase II study is designed to rapidly assess hemoglobin response and key markers of hemolysis to confirm whether this deeper biology translates into broader clinical benefit. We look forward to reporting top line Phase IIb data in low-risk MDS in the first half of this year, followed by top line Phase II data in sickle cell disease in the second half of 2026. With that, please move to the next slide, and I will hand the call back to Brian for closing remarks.