Phanes Therapeutics Announces Positive Phase 2 Results of Spevatamig (PT886) in Combination with Chemotherapy in Frontline (1L) Treatment of Metastatic PDAC at ASCO GI 2026

SAN DIEGO, Jan. 9, 2026 /PRNewswire/ -- 

• Data presented at ASCO GI 2026 show spevatamig, an anti-CLDN18.2/CD47 bsAb, in combination with chemotherapy, has the potential to be an effective first-line (1L) treatment in patients with CLDN18.2 positive metastatic pancreatic ductal adenocarcinoma (mPDAC)
• Spevatamig's unique molecular design mitigates hematological toxicity, and improves gastrointestinal (GI) tolerability (nausea and vomiting) as evidenced by the TWINPEAK study, which includes greater than 100 patients in the United States
• 2 mg/kg QW spevatamig + GnP showed promising efficacy when compared with published studies of GnP in 1L mPDAC, while data for 3 mg/kg QW spevatamig + GnP is still maturing
• Spevatamig is a novel immunotherapy which has the potential to become the first innate immunity enhancer (I2E) for a solid tumor indication and is combinable with various cancer therapies

Phanes Therapeutics, Inc. (Phanes), a clinical stage biotech company focused on innovative drug discovery and development in oncology, announced the first clinical data evaluating spevatamig in combination with chemotherapy in frontline (1L) treatment of metastatic pancreatic ductal adenocarcinoma (mPDAC). The data was presented at the American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO GI) 2026; Abstract #709. This marks the first public release of Phanes' clinical trial data from their ongoing U.S. multi-center study with spevatamig.

The TWINPEAK study (NCT05482893) is an ongoing multi-cohort Phase 1 monotherapy dose escalation, and Phase 2 combination expansion and dose optimization study in patients with GI carcinomas. Combination expansion cohorts include various combinations with chemotherapy and/or an immune-checkpoint inhibitor. As of December 12, 2025, 107 patients have been treated with spevatamig in the US collectively in monotherapy and combination settings. Of these patients, 42 with 1L mPDAC have been 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 >2 mg/kg QW spevatamig + GnP still maturing. Of note:

• Spevatamig has demonstrated a favorable 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 treatment-emergent anemia, neutropenia or thrombocytopenia were observed during the study.
• At 2 mg/kg QW spevatamig + GnP dose level, the rates of anemia, neutropenia and thrombocytopenia were comparable to those observed in the GnP treatment arms from pivotal trials. No Grade ≥ 3 treatment-emergent nausea or vomiting events were reported, and no dose reductions or treatment discontinuations due to nausea or vomiting occurred. No CRS was observed.
• 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%.
• Responses were observed across CLDN18.2 scores ≥ 10% (≥ 2+ staining). Of note, 85% of patients screened met this CLDN18.2 threshold requirement.

Phanes' data of spevatamig featured at ASCO GI 2026 can be found here: https://www.phanesthera.com/our-science/

ABOUT SPEVATAMIG
Spevatamig is a first-in-class native IgG-like bispecific antibody (bsAb) targeting claudin 18.2 and CD47. It was granted orphan drug designation (ODD) for the treatment of pancreatic cancer by the FDA in 2022 and was granted Fast Track designation for the treatment of patients with metastatic claudin 18.2-positive pancreatic adenocarcinoma in 2024. In 2023, Phanes entered into a clinical collaboration agreement with Merck (known as MSD outside the US and Canada) to study spevatamig in combination with Merck's anti-PD-1 therapy, pembrolizumab.

The multi-center Phase 1/2 clinical trial of spevatamig (NCT05482893), known as the TWINPEAK study, is currently evaluating the safety, tolerability, pharmacokinetics, and preliminary efficacy of spevatamig in patients with advanced gastric, gastroesophageal junction, pancreatic ductal or biliary tract adenocarcinomas. The Phase 2 study of spevatamig has begun in China.

ABOUT PHANES THERAPEUTICS
Phanes Therapeutics, Inc. is a clinical stage biotech company focused on innovative drug discovery and development in oncology. Currently, it is conducting three Phase 1/2 clinical trials, including the MORNINGSTAR study with its best-in-class monoclonal antibody (mAb) program, mavrostobart, the TWINPEAK study with spevatamig and the SKYBRIDGE study with peluntamig. Both spevatamig and peluntamig are first-in-class bispecific antibodies and have been granted orphan drug designations as well as Fast Track designations by the FDA.

CONTACT: [email protected]

SOURCE Phanes Therapeutics, Inc.