Immuneering Doses First Patient in Phase III MAPKeeper 301 Trial of Atebimetinib Plus Modified Gemcitabine/Nab-Paclitaxel in Metastatic Pancreatic Cancer
核心洞察
Immuneering has dosed the first patient in the pivotal phase III MAPKeeper 301 study of atebimetinib (搜索) plus modified gemcitabine/nab-paclitaxel in first-line metastatic pancreatic cancer (搜索).
The global trial randomizes patients with metastatic pancreatic ductal adenocarcinoma (搜索) and no prior systemic therapy to atebimetinib (搜索) 320 mg once daily plus mGnP or standard-of-care GnP alone.
Overall survival is the primary endpoint, with progression-free survival, overall response rate, disease control rate, safety and quality of life as key secondary endpoints; top-line data are expected in mid-2028.
Immuneering Corporation has dosed the first patient in a pivotal phase III study of its lead product candidate, atebimetinib (搜索) (IMM-1-104), in combination with modified gemcitabine/nab-paclitaxel (mGnP) for the first-line treatment of metastatic pancreatic cancer (搜索). The company's shares rose 5.1% following the announcement.
The global phase III MAPKeeper 301 study will evaluate the safety and efficacy of atebimetinib (搜索), described as a dual MEK (搜索) inhibitor, plus mGnP in patients with metastatic pancreatic ductal adenocarcinoma (搜索) (PDAC) who have received no prior systemic anti-cancer therapy.
Trial Design and Endpoints
In MAPKeeper 301, patients are randomized to receive either atebimetinib (搜索) at 320 mg once daily in combination with mGnP or standard-of-care GnP alone. The primary endpoint is overall survival (OS). Key secondary endpoints include progression-free survival, overall response rate, disease control rate, safety and tolerability, and quality of life.
Top-line data from the MAPKeeper 301 study are expected to be announced in mid-2028.
Prior Phase IIa Survival Signal
The phase III launch follows updated clinical data from an earlier-stage study. In January 2026, Immuneering reported positive updated OS and safety data from the phase IIa study arm evaluating atebimetinib (搜索) plus mGnP in first-line pancreatic cancer (搜索). In that analysis, the combination produced 64% OS at 12 months compared with 35% for the standard of care in the given patient population.
Beyond the first-line combination setting, the company is also developing atebimetinib (搜索) as a monotherapy in third-line pancreatic cancer (搜索).
Expansion Into RAS-Mutant NSCLC
Immuneering is additionally evaluating atebimetinib (搜索) in combination with Regeneron's anti-PD-1 (搜索) therapy Libtayo (cemiplimab) in a phase II study in patients with first-line RAS (搜索)-mutant non-small-cell lung cancer (搜索) (NSCLC), with dosing expected to begin in the second half of 2026.
The collaboration with Regeneron was established in February 2025 to evaluate atebimetinib (搜索) plus Libtayo in NSCLC. Under the agreement, Immuneering will fund the planned studies while Regeneron will supply Libtayo, which is approved for multiple cancer indications.
Pipeline Positioning
Recent investor and scientific discussion has centered on atebimetinib (搜索)'s reported ability to reduce tumor volume while preserving body mass, with observers noting the potential for extended survival in pancreatic cancer (搜索) models. The company also participated in the RAS (搜索)-Targeted Drug Development Summit in Boston, where it shared details on pipeline progress and dual-mechanism approaches.
Year to date, Immuneering shares have declined 37.4%, compared with a 3.3% decrease for the industry. The stock currently carries a Zacks Rank #3 (Hold).