San Diego, California, August 14, 2026
Phanes Therapeutics, Inc., a clinical-stage biotechnology company focused on immuno-oncology drug discovery and development, announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to spevatamig for the treatment of patients with advanced and metastatic biliary tract carcinoma (BTC). The regulatory designation recognizes the significant unmet medical need associated with advanced biliary tract cancer and supports the continued clinical development of spevatamig, an investigational CLDN18.2/CD47 bispecific antibody. The candidate is currently being evaluated in Phase 2 studies across multiple gastrointestinal cancer indications.
FDA Fast Track Supports Spevatamig Development
The FDA’s Fast Track designation represents an important regulatory milestone for spevatamig, which Phanes describes as an innate immunity enhancer (I2E), an emerging class of immuno-oncology agents. The designation is intended to support development of therapies addressing serious conditions with unmet medical needs. For Phanes, the decision adds regulatory momentum to the company’s ongoing efforts to evaluate spevatamig in patients with advanced and metastatic biliary tract carcinoma. Spevatamig has previously received other FDA regulatory designations for oncology indications. In 2022, the FDA granted orphan drug designation for pancreatic cancer, followed by Fast Track designation in 2024 for patients with metastatic CLDN18.2-positive pancreatic adenocarcinoma. Phanes is now expanding the clinical development program into biliary tract cancer, where treatment options remain limited for patients with advanced disease. The company has also expanded its clinical trial collaboration with Merck to evaluate spevatamig in combination with pembrolizumab for the frontline treatment of biliary tract cancer. This collaboration reflects Phanes’ strategy of investigating the bispecific antibody alongside established immuno-oncology approaches and other anticancer therapies.
Bispecific Antibody Targets CLDN18.2 and CD47
Spevatamig is described by Phanes as a first-in-class native IgG-like bispecific antibody designed to target claudin 18.2 (CLDN18.2) and CD47. The candidate is intended to engage mechanisms of innate immunity, with I2Es designed to activate immune cells such as macrophages and dendritic cells to recognize and destroy cancer cells. According to Phanes, this mechanism could complement the activity of immune checkpoint inhibitors (ICIs) by providing an additional way to stimulate the immune system against tumors. The company believes this approach may be particularly relevant to “cold tumors,” which can be less responsive to checkpoint inhibitor therapies alone. Spevatamig is being investigated as a potential combination therapy with chemotherapy, pembrolizumab, and other anticancer treatments.The company is conducting multiple clinical studies to evaluate the candidate’s safety, tolerability, and efficacy. One Phase 2 program is evaluating spevatamig combined with chemotherapy in patients with pancreatic ductal adenocarcinoma (PDAC) in the first-line setting. Phanes has reported completion of enrollment in this study while continuing clinical development in biliary tract carcinoma.
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Expanding Phanes’ Immuno-Oncology Pipeline
The FDA Fast Track designation strengthens Phanes Therapeutics’ broader strategy of developing innovative biologics for high unmet medical needs in cancer. The company currently has three Phase 2 clinical programs involving spevatamig, peluntamig, and mavrostobart. Phanes said both spevatamig and peluntamig are first-in-class bispecific antibodies that have received FDA orphan drug and Fast Track designations. Phanes is also leveraging proprietary technology platforms, including PACbody®, SPECpair®, and ATACCbody®, to develop novel biologic medicines. The company’s focus on bispecific antibodies and innate immune activation reflects the growing interest in next-generation immuno-oncology strategies designed to address tumors that may respond inadequately to existing treatments.
The advancement of spevatamig into biliary tract carcinoma therefore represents an important step in the candidate’s clinical development. The FDA Fast Track designation, ongoing Phase 2 studies, and expanded collaboration with Merck collectively support continued investigation of spevatamig as a potential treatment option for patients with advanced gastrointestinal cancers. While the designation does not establish clinical efficacy or guarantee approval, it provides regulatory recognition of the need for additional treatment approaches in advanced and metastatic BTC and supports further clinical evaluation of this emerging bispecific immuno-oncology therapy.
Source: Phanes Therapeutics press release
