AZD1613 is a first-in-class PAPPA-1 inhibitor from AstraZeneca that targets a completely new pathway — reducing local IGF signaling that drives cyst growth in PKD kidneys.
Background
AstraZeneca's entry into PKD represents a major pharma company committing to a completely novel biological pathway. PAPPA-1 (Pregnancy-Associated Plasma Protein-A) is an enzyme that cleaves IGF binding proteins, releasing free IGF-1 locally in tissues. In polycystic kidneys, this local IGF signaling promotes cyst cell growth. By blocking PAPPA-1, AZD1613 aims to reduce IGF availability specifically in cystic tissue without affecting systemic growth hormone signaling.
How It Works
PAPPA-1 is a metalloproteinase that cleaves IGFBP-4 and IGFBP-5, releasing bioactive IGF-1 locally. In PKD kidneys, cyst-lining cells overexpress PAPPA-1, creating a local growth factor environment that drives proliferation. AZD1613 inhibits PAPPA-1 enzymatic activity, keeping IGF-1 bound to its binding proteins and unavailable to stimulate cyst growth. This is an elegant approach because it targets the disease locally rather than systemically.
Clinical Trial Details
The PIONEER-PKD trial (NCT07228364) is a Phase 1, multiple ascending dose study in ADPKD patients. It tests both subcutaneous and IV administration routes in approximately 40 patients at sites in the US, UK, and China. Started November 2025 with estimated completion January 2027.
Why It's Promising
This is one of the most scientifically novel approaches in the PKD pipeline. AstraZeneca's resources and track record in kidney disease (they developed dapagliflozin/Farxiga) give confidence in development capability. If the mechanism works, it could be complementary to existing approaches since it targets a completely different pathway.
Limitations & Concerns
Very early stage — Phase 1 is only establishing safety and dosing. The PAPPA-1/IGF axis in human PKD is less validated than other targets. Could take 8–12 years to reach market if everything goes well.