Akamis Bio Completes Enrollment of the Phase 1b FORTRESS Study of NG-350A in Mismatch Repair-Proficient Locally Advanced Rectal Cancer

Phase 1b FORTRESS study enrolled 33 patients with mismatch repair proficient locally advanced rectal cancer across seven sites in U.S. and U.K.

Study continues to evaluate the efficacy and safety profile of NG-350A in combination with chemoradiotherapy with topline results anticipated in first half of 2027

CAMBRIDGE, MA - October 14, 2026 - Akamis Bio, a clinical-stage oncology company working to advance the standard of care in colorectal cancer, today announced that it has completed enrollment of the Phase 1b FORTRESS study of NG-350A, an oncolytic immunotherapy for the treatment of mismatch repair-proficient (pMMR) locally advanced rectal cancer (LARC). The FORTRESS study enrolled 33 participants with pMMR LARC across seven sites in the United States and the United Kingdom to evaluate the efficacy and safety profile of NG-350A in combination with chemoradiotherapy (CRT).

Topline results from the FORTRESS study are anticipated in the first half of 2027, and subject to discussions with regulators, the company expects to initiate a Phase 2 randomized controlled trial of NG-350A in combination with CRT in pMMR LARC in the second half of 2027.

The Phase 1b FORTRESS study (NCT06459869) is assessing the anti-tumor effects of NG-350A combined with CRT following a 12-week active treatment period to establish whether NG-350A can improve composite response rates in pMMR LARC patients relative to expected outcomes from CRT alone. The primary endpoint of the FORTRESS study is the composite response rate defined as the proportion of patients achieving a clinical complete response (cCR) or a near clinical complete response (ncCR) at 12 weeks. The benchmark composite response rate (cCR + ncCR) for CRT alone at 12 weeks is approximately 25 percent.

"Completion of enrollment of the FORTRESS study marks an important milestone as we evaluate the potential of NG-350A plus chemoradiotherapy to advance the standard of care for patients living with mismatch repair proficient locally advanced rectal cancer," said Oliver Rosen, MD, Chief Medical Officer of Akamis Bio. "Preliminary results from the FORTRESS study indicate that NG-350A combined with chemoradiotherapy has the potential to improve tumor response rates relative to expected rates for chemoradiotherapy alone. We look forward to reporting topline data across the full 33 enrolled FORTRESS participants in the first half of 2027 in preparation for the initiation of a randomized controlled Phase 2 study of NG-350A plus chemoradiotherapy in a pMMR LARC patient population."

In data shared earlier this year at the American Association for Cancer Research (AACR) Annual Meeting, NG-350A combined with CRT demonstrated a composite response rate of 50 percent across the first 10 patients who completed the 12-week active treatment period, with no serious adverse events or new safety signals identified related to NG-350A. The company previously announced that NG-350A has received Fast Track designation from the U.S. Food and Drug Administration for the treatment of pMMR LARC.

About NG-350A
NG-350A is a clinical-stage, intravenously delivered oncolytic immunotherapy designed to drive intratumoral expression of a CD40 agonist monoclonal antibody triggering the activation of antigen-presenting cells (APCs) resident in solid tumors and their draining lymph nodes. Once activated, APCs recruit T cells into the vicinity of the tumor to deliver a potent anti-tumor immune response. Akamis Bio has evaluated NG-350A's safety, tolerability, and preliminary efficacy as a monotherapy (FORTITUDE study) and in combination with pembrolizumab (FORTIFY study) in patients with metastatic or advanced epithelial tumors. Across these studies, NG-350A has demonstrated a consistent safety and tolerability profile, as well as strong evidence of tumor-selective delivery, replication and transgene expression.

About the FORTRESS Study
The Phase 1b FORTRESS study (NCT06459869) is an open-label, single-arm, multicenter trial of NG-350A in combination with CRT in adult patients with pMMR LARC and at least one risk factor for local or distant recurrence or with oligometastatic disease. The FORTRESS study builds upon the Akamis Bio-supported CEDAR study, which showed a significantly greater composite response rate in LARC patients treated with a combination of Akamis Bio's first-generation oncolytic immunotherapy (EnAd) and chemoradiotherapy (CRT), relative to expected outcomes using standard-of-care CRT alone. The FORTRESS study enrolled 33 patients aged eighteen and older with histologically confirmed, locally advanced adenocarcinoma of the rectum (clinical stage II-III based on pelvic MRI). During the 12-week active treatment period, patients receive NG-350A plus CRT (oral capecitabine plus long-course intensity-modulated radiotherapy). The primary endpoint of the FORTRESS study is the composite response rate, defined as the proportion of patients achieving a clinical complete response (cCR) or a near clinical complete response (ncCR) at 12 weeks. Key secondary endpoints include the incidence and severity of adverse events, characterization of the anti-tumor effects of NG-350A in combination with CRT (including clinical response outcome and magnetic resonance tumor regression grade [mrTRG]), and assessment of circulating tumor DNA (ctDNA) clearance.

About Locally Advanced Rectal Cancer (LARC)

Colorectal cancer (CRC) is the second leading cause of cancer-related death in the United States, and it has recently emerged as the leading cause in patients under 50 years of age. Approximately 159,000 people are newly diagnosed with CRC each year, including about 53,000 with rectal cancer of which approximately 30,000 are diagnosed with LARC. In patients with LARC, the rectal cancer has spread to the lymph nodes and/or through the muscle and into the outermost layers of the rectum. In more severe cases, the rectal cancer may extend through the wall of the rectum where it can attach to other organs or structures. Approximately 95 percent of LARC patients have mismatch repair-proficient (pMMR) tumors which have a functional DNA mismatch repair system.

About Akamis Bio

Headquartered in Cambridge, Massachusetts, Akamis Bio is a clinical-stage oncology company developing systemically administered oncolytic immunotherapies to treat colorectal cancer, with an initial focus on locally advanced rectal cancer (LARC). Its proprietary Tumor-Specific Immuno-Gene Therapy (T-SIGn®) platform is designed to deliver novel immunotherapeutic proteins, biomolecules and transgene combinations to treat solid tumors, with its lead clinical-stage program, NG-350A, driving intratumoral expression of a CD40 agonist monoclonal antibody. To learn more, please visit www.akamisbio.com.

Media Contact:

Jason Glashow
Glashow Strategic Communications
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