Phanes Therapeutics Inc, a California-based clinical stage biotech company focused on innovative drug discovery and development in oncology, on Friday reported the first clinical data evaluating spevatamig in combination with chemotherapy in frontline (1L) treatment of metastatic pancreatic ductal adenocarcinoma (mPDAC).

This data was presented at the American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO GI) 2026.

The TWINPEAK study is an ongoing multi-cohort Phase 1 monotherapy dose escalation and Phase 2 combination expansion and dose optimisation study in patients with GI carcinomas. Combination expansion cohorts include various combinations with chemotherapy and/or an immune-checkpoint inhibitor.

As of 12 December 2025, 107 patients have been treated with spevatamig in the United States in monotherapy and combination settings. Of these patients, 42 with 1L mPDAC were treated with spevatamig + GnP across several dosing regimens. Data from the 2 mg/kg weekly (QW) + GnP regimen was presented at ASCO GI 2026, with data from dosing regimens greater than 2 mg/kg QW spevatamig + GnP still maturing.

Spevatamig has demonstrated a favourable safety profile. In monotherapy, no CRS or DLTs were observed. The maximum tolerated dose (MTD) has not been reached in either the monotherapy or combination therapy setting. No Grade 3 or higher treatment-emergent anaemia, neutropenia or thrombocytopenia were observed during the study.

In the 2 mg/kg QW spevatamig + GnP 1L mPDAC dosing regimen (n=15), the DCR was 93% and the ORR was 40% (6/15 achieved partial response, with 1 patient pending confirmation).

The median progression-free survival (mPFS) was 7.3 months with a 6-month PFS rate of 59%. The median overall survival (mOS) was 13.2 months and still maturing while 6-month OS rate was 93%.