San Diego, California, USA, October 14, 2026
Phanes Therapeutics, Inc., a clinical-stage biotechnology company focused on innovative immuno-oncology drug development, has announced that the first patient with colorectal cancer (CRC) has been dosed with spevatamig in a clinical study. The milestone expands the clinical investigation of spevatamig, an investigational bispecific antibody designed to target two proteins associated with cancer biology: claudin 18.2 (CLDN18.2) and CD47. The treatment is being evaluated as part of the company’s broader strategy to develop novel immunotherapies for patients with advanced gastrointestinal cancers. The announcement represents progress in the clinical development of spevatamig as researchers investigate its safety, tolerability, pharmacokinetics and preliminary antitumor activity across multiple cancer types.
Spevatamig Targets Two Cancer-Associated Proteins
Spevatamig, also known as PT886, is a first-in-class, native IgG-like bispecific antibody developed to engage CLDN18.2 and CD47. Bispecific antibodies are engineered to recognize two different molecular targets, potentially allowing them to influence multiple biological processes through a single therapeutic molecule. CLDN18.2 is a protein found in certain gastrointestinal tumors, while CD47 is associated with a biological signal that can help cells avoid destruction by immune cells. By targeting these proteins, spevatamig is designed to support an approach known as innate immunity enhancement, an emerging area of immuno-oncology research. The strategy aims to help the immune system recognize and respond to cancer cells. However, the extent to which this mechanism can produce meaningful clinical benefits in colorectal cancer remains under investigation. The U.S. Food and Drug Administration previously granted spevatamig Orphan Drug Designation for pancreatic cancer in 2022 and Fast Track designation for metastatic CLDN18.2-positive pancreatic adenocarcinoma in 2024. The company has also announced Fast Track designation for advanced and metastatic biliary tract carcinoma. These regulatory designations support development for specific conditions but do not constitute approval for marketing or establish that the investigational treatment is effective.
TWINPEAK Study Evaluates Advanced Gastrointestinal Cancers
The colorectal cancer patient is participating in the multicenter Phase 1/2 TWINPEAK clinical study (NCT05482893), which evaluates spevatamig in patients with advanced gastrointestinal cancers. The study encompasses several disease settings, including gastric cancer, gastroesophageal junction cancer, pancreatic ductal adenocarcinoma, colorectal cancer and biliary tract adenocarcinoma. The trial is designed to assess safety, tolerability, pharmacokinetics and preliminary efficacy. Safety and tolerability assessments help researchers understand adverse effects and determine how well participants can receive the treatment. Pharmacokinetic analyses examine how the drug moves through the body, including its absorption, distribution and elimination. Preliminary efficacy assessments explore whether the investigational treatment shows evidence of antitumor activity. The inclusion of colorectal cancer broadens the clinical investigation of spevatamig beyond other gastrointestinal malignancies already being studied. Nevertheless, the announcement of the first patient dosed is an early development milestone rather than evidence of clinical success. Additional patient enrollment, treatment, monitoring and data analysis will be needed to determine the therapy’s potential role in CRC treatment. Phanes Therapeutics has also reported Phase I and Phase II clinical trials in China evaluating spevatamig in gastrointestinal cancers. Together, these clinical development activities reflect the company’s efforts to investigate the antibody across relevant patient populations and treatment settings.
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Immuno-Oncology Research and Future Development
Phanes Therapeutics is developing spevatamig as part of its broader immuno-oncology pipeline, which includes investigational biologics intended to address significant unmet medical needs in cancer care. In 2023, the company entered into a clinical collaboration agreement with Merck to study spevatamig in combination with pembrolizumab, an immune checkpoint inhibitor. Such combinations are being explored to investigate whether different immune-related mechanisms can complement one another in cancer treatment. For colorectal cancer, the ongoing study will need to establish the safety profile and determine whether spevatamig demonstrates encouraging antitumor activity. No treatment approval or definitive clinical benefit for colorectal cancer has been established by this first-patient dosing announcement. Future findings from the TWINPEAK study may help guide decisions about further clinical development and potential combination strategies. The first colorectal cancer patient dosed marks another step in evaluating spevatamig as an investigational therapy for advanced gastrointestinal malignancies. As clinical research progresses, additional evidence will be essential to determine whether this dual-targeting antibody can offer a meaningful treatment option for patients who need new approaches to cancer care.
Source: Phanes Therapeutics press release
