Phanes Therapeutics, a clinical-stage biotechnology company focused on oncology drug discovery and development, has announced the first clinical data evaluating spevatamig in combination with chemotherapy for the frontline (first-line) treatment of metastatic Pancreatic Ductal Adenocarcinoma (mPDAC).

The data were presented at the American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO GI) 2026, marking the first public disclosure of clinical trial results from Phanes’ ongoing multi-centre study in the United States.

The findings were generated from the Twinpeak study, an ongoing multi-cohort Phase I/II trial evaluating spevatamig as both a monotherapy and in combination regimens in patients with gastrointestinal carcinomas. The study includes a Phase I monotherapy dose-escalation stage and a Phase II combination expansion and dose-optimisation phase, with cohorts assessing spevatamig in combination with chemotherapy and immune checkpoint inhibitors.

As of December 12, 2025, a total of 107 patients have been treated with spevatamig across monotherapy and combination settings in the US. Among them, 42 patients with first-line mPDAC received spevatamig in combination with Gemcitabine and nab-Paclitaxel (GnP) across multiple dosing regimens. Data presented at ASCO GI 2026 focused on the two mg/kg weekly spevatamig plus GnP regimen, while higher-dose cohorts continue to mature.

The study demonstrated a favourable safety profile for the medicine. No Cytokine Release Syndrome (CRS) or Dose-Limiting Toxicities (DLTs) were observed in the monotherapy setting, and the maximum tolerated dose has not been reached in either monotherapy or combination therapy. Additionally, no Grade three or higher treatment-emergent anemia, neutropenia or thrombocytopenia were reported.

At the 2 mg/kg QW spevatamig plus GnP dose level, the incidence of hematologic adverse events was comparable to those reported in pivotal GnP trials. No Grade three or higher nausea or vomiting was observed, and there were no dose reductions or treatment discontinuations due to these events. CRS was not reported in the combination cohort.

In the first-line mPDAC cohort treated with 2 mg/kg QW spevatamig plus GnP, the Disease Control Rate (DCR) reached 93 percent, while the Objective Response Rate (ORR) was 40 percent, with six patients achieving a partial response and one response pending confirmation.

The median Progression-Free Survival (mPFS) was 7.3 months, with a six-month PFS rate of 59 percent. Median Overall Survival (MOS) was reported at 13.2 months and remains immature, while the six-month overall survival rate was 93 percent.

Clinical responses were observed across patients with CLDN18.2 expression scores of 10 percent or higher. Notably, 85 percent of screened patients met the CLDN18.2 expression threshold required for study enrollment.

Phanes Therapeutics said the data support the continued clinical development of spevatamig as a potential new treatment option for patients with metastatic pancreatic cancer, a disease with significant unmet medical need.