Peptide News Digest

#Mcrpc

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Clinical Trials · View digest

Telix ProstACT Global Phase 3 Part 1 ASCO 2026: PSMA-Targeted Lutetium-177 Rosopatamab Radio-ADC Meets Primary Safety Objectives in PSMA-Positive mCRPC

Telix Pharmaceuticals reported ProstACT Global Phase 3 Part 1 data at ASCO 2026 as a late-breaking presentation. TLX591-Tx (lutetium-177 rosopatamab tetraxetan) — a PSMA-targeted lutetium radio-antibody-drug conjugate — met its primary safety objectives in the safety and dosimetry lead-in, demonstrating an acceptable tolerability profile with no new safety signals when combined with enzalutamide (Xtandi), abiraterone (Zytiga), or followed by docetaxel in PSMA-positive metastatic castration-resistant prostate cancer (mCRPC). ProstACT Global is an international Phase 3 trial evaluating TLX591-Tx plus standard of care versus standard of care alone. The drug sits in the PSMA-targeted radioligand class alongside Novartis's approved Pluvicto (lutetium-177 PSMA-617, a peptide-based radioligand), but uses an antibody rather than a small-molecule peptide as the targeting vector. The PSMA radioligand field — Pluvicto, ProstACT, plus the Aktis AKY-2519 B7-H3 miniprotein radioconjugate covered earlier this week — is one of the fastest-growing targeted-conjugate categories in oncology.

Clinical Trials · View digest

Aktis Oncology AKY-2519 First-in-Human Imaging + Dosimetry Data: B7-H3-Targeting Miniprotein Radioconjugate Shows Robust Tumor Uptake in mCRPC and Solid Tumors (ASCO 2026)

Aktis Oncology released first-in-human clinical imaging and dosimetry data on AKY-2519 ahead of ASCO 2026. AKY-2519 is a miniprotein radioconjugate — a small synthetic protein scaffold (akin to engineered peptide architecture) linked to a therapeutic radionuclide — targeting B7-H3, an antigen overexpressed in multiple solid tumors including metastatic castration-resistant prostate cancer (mCRPC) and non-small cell lung cancer. The Phase 1 data demonstrated robust tumor uptake and limited normal-tissue exposure across multiple B7-H3-expressing tumor types. Two ASCO 2026 poster presentations cover the imaging and dosimetry results. The FDA cleared the IND for AKY-2519 in March 2026; a Phase 1b clinical trial in mCRPC patients is ongoing, with a second Phase 1b in various B7-H3-expressing tumor types expected to initiate in H2 2026. AKY-2519 joins Novartis's Pluvicto (PSMA-617) and Lutathera (DOTATATE) in the small but growing class of peptide-related radioconjugates with first-in-human or commercial validation.