Dr Barbacid pancreatic cancer mice regression

Mariano Barbacid’s pancreatic-cancer mouse result is real, but the social-media version leaves out several facts that matter. The work was announced by Spain’s National Cancer Research Centre, or CNIO, on January 28 and described in a PNAS paper as a preclinical study in mice, not a human trial. CNIO said the regimen produced complete and lasting regression of pancreatic tumors in three mouse models of pancreatic ductal adenocarcinoma, the most common form of pancreatic cancer. Barbacid also said in the CNIO release that researchers were “not yet in a position” to start clinical trials with the triple therapy. ### What exactly did Barbacid’s group report? The PNAS study said the team used a targeted three-part strategy against KRAS-driven pancreatic cancer biology. CNIO described the approach as blocking KRAS signaling at three points: downstream through RAF1, upstream through EGFR and through an orthogonal STAT3 pathway. In the paper summary surfaced by biorxiv and QxMD, the authors said genetic ablation of those three nodes led to complete and permanent regression of orthotopic pancreatic tumors driven by KRAS and TP53 mutations. (sciencesources.eurekalert.org) CNIO said the treatment was then applied in three mouse models of pancreatic ductal adenocarcinoma and induced significant, lasting regression without significant toxicities. MedicalXpress, which republished the CNIO release, said the study described “robust regression” of experimental pancreatic cancers while avoiding tumor resistance. (biorxiv.org) ### Did the mice all have their tumors disappear? CNIO’s release said the tumors were completely eliminated in mice and that resistance did not develop. Several secondary reports based on the paper and release said there was no evidence of relapse for more than 200 days after treatment in at least one model set, but the social-media posts circulating this week did not provide the sample size, dosing schedule or full methods. Those details belong in the paper itself, not in an X thread. (cnio.es) The distinction matters because “all treated mice” is stronger than the wording in the institutional release unless readers can inspect the underlying methods and figures. CNIO’s public summary supports complete and durable elimination in mouse models, but it does not, by itself, substitute for the full experimental breakdown. ### Was this a brand-new claim on X? (sciencesources.eurekalert.org) The January 2026 CNIO announcement shows the result was already public months before the May 2026 social-media post. EurekAlert carried the CNIO release on February 3, 2026, and the release said the study had been published in PNAS. That means the core claim is not a fresh disclosure from this week; what is new is renewed attention to it online. (sciencesources.eurekalert.org) ### What did Barbacid say about human treatment? Barbacid said in the CNIO release that researchers were “not yet in a position to carry out clinical trials with this triple therapy.” CNIO also said the findings “open the road” to designing combination therapies that may improve survival in pancreatic ductal adenocarcinoma, but added that this would not happen in the short term. (sciencesources.eurekalert.org) That caution is consistent with the group’s broader research program. CNIO’s Experimental Oncology Group says it focuses on KRAS-mutant lung and pancreatic tumors in genetically engineered mouse models and has been working on strategies to overcome the partial responses and rapid resistance seen with KRAS inhibitors. (sciencesources.eurekalert.org) ### Is there anything else readers should know about the paper? PNAS search results now show a retraction notice tied to the article, stating that editors retracted it over an undisclosed competing interest. The notice says Barbacid and two coauthors held financial interests in Vega Oncotargets that were not disclosed at submission. The retraction notice shown in PNAS search results does not say the paper was withdrawn for fabricated data; it identifies a disclosure issue. (cnio.es) The next place to look is the full PNAS record and any CNIO or author response on the retraction, along with any updated manuscript, correction or follow-on publication from Barbacid’s group. (pnas.org)