Pyxis Oncology, Inc. has announced promising preliminary data for its investigational drug PYX-201, which achieved a confirmed 50% objective response rate (ORR) in a study involving six heavily pretreated patients with head and neck squamous cell carcinoma (HNSCC).

Among these patients, the treatment resulted in one complete response and two partial responses, leading to a remarkable 100% disease control rate.

The patients in this study had a median of four prior lines of cancer therapies, highlighting the heavily pretreated nature of the cohort.

PYX-201 has demonstrated a favorable safety profile, being generally well-tolerated with a low incidence of severe treatment-related adverse events, making it a strong candidate for both monotherapy and combination therapies.

In the ongoing Phase 1 trial, 80 patients have been dosed with PYX-201 at varying levels from 0.3 mg/kg to 8.0 mg/kg, focusing on safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy.

The overall ORR across six solid tumor types in this Phase 1 trial was reported at 26%, with dose-dependent responses supporting the first-in-concept mechanism of this novel extracellular antibody-drug conjugate (ADC).

Encouraging responses were also noted in other cancer types, including ovarian cancer, non-small cell lung cancer (NSCLC), HR+/HER2- breast cancer, triple-negative breast cancer (TNBC), and sarcoma.

Looking ahead, Pyxis Oncology has established a collaboration with Merck to evaluate the combination of PYX-201 with KEYTRUDA® (pembrolizumab) in various cancers, including HNSCC and HR+/HER2- breast cancer, with dosing expected to begin in early 2025.

An investor event is scheduled for today, November 20, 2024, to discuss the preliminary Phase 1 data, with multiple data updates regarding PYX-201 anticipated throughout 2025.

PYX-201 targets Extradomain-B Fibronectin (EDB+FN), a unique component of the tumor extracellular matrix, setting it apart from other antibody-drug conjugates currently in development.

Future studies for PYX-201 will include monotherapy expansion cohorts and combination studies, with preliminary clinical data expected in 2025 and 2026.

The significant clinical responses observed in HNSCC patients underscore the potential of PYX-201 as an effective treatment option for those who have undergone multiple previous therapies.