Osimertinib and anti-HER3 combination therapy engages immune dependent tumor toxicity via STING activation in trans

Over the past decade, immunotherapy delivered novel treatments for many cancer types. However, lung cancer still leads cancer mortality, and non-small-cell lung carcinoma patients with mutant EGFR cannot benefit from checkpoint inhibitors due to toxicity, relying only on palliative chemotherapy and the third-generation tyrosine kinase inhibitor (TKI) osimertinib. This new drug extends lifespan by 9-months vs. second-generation TKIs, but unfortunately, cancers relapse due to resistance mechanisms and the lack of antitumor immune responses. Here we explored the combination of osimertinib with anti-HER3 monoclonal antibodies and observed that the immune system contributed to eliminate tumor cells in mice and co-culture experiments using bone marrow-derived macrophages and human PBMCs. Osimertinib led to apoptosis of tumors but simultaneously, it triggered inositol-requiring-enzyme (IRE1α)-dependent HER3 upregulation, increased macrophage infiltration, and activated cGAS in cancer cells to produce cGAMP (detected by a lentivirally transduced STING activity biosensor), transactivating STING in macrophages. We sought to target osimertinib-induced HER3 upregulation with monoclonal antibodies, which engaged Fc receptor-dependent tumor elimination by macrophages, and STING agonists enhanced macrophage-mediated tumor elimination further. Thus, by engaging a tumor non-autonomous mechanism involving cGAS-STING and innate immunity, the combination of osimertinib and anti-HER3 antibodies could improve the limited therapeutic and stratification options for advanced stage lung cancer patients with mutant EGFR.

[Thromboses of heart valve prostheses: predisposing and prognostic factors based on a study of 41 patients]

Forty one patients were admitted with a diagnosis of prosthetic valve thrombosis. One patient was thrombolyzed successfully, and 40 underwent surgical procedures. In 13 cases, prosthetic valve thrombosis occurred in the first month after valve replacement. 18 patients were in functional class IV of the NYHA classification. Among the thrombosed prostheses, 91% were mechanical, and 61% in mitral position. Adequacy of anticoagulation was the most important risk factor, as this treatment was inappropriate in 20 patients. In 10 other patients, it had been changed for medical (bleeding events, pregnancy) or surgical (non cardiac surgery) reasons. The perioperative mortality rate was high (32.4%). It was 12% in patients in functional class II and 46% in those in class IV (p < 0.05). This underlines the value of early diagnosis, in which echocardiography, especially with a transesophageal probe, takes a major place, allowing prompt surgical treatment.

[C-reactive protein in bacterial meningitis in adults]

In order to assess the benefits of serial assays of C-reactive protein in the course of bacterial meningitis in adults, daily blood samples were taken for CRP measurement during 10 days in 21 consecutive patients (mean age: 24 +/- 8 years) hospitalized for bacterial meningitis principally due to Neisseria meningitidis (n = 15). The highest CRP level (178 +/- 38 mg/l) was present on admission, followed by a regular decrease occurring in uncomplicated meningitis until normal level was achieved on day 9. The CRP kinetics was not influenced by the type of causative micro-organism. This study shows that CRP kinetics in adults is similar to that reported in children. The benefit of CRP assays in optimizing the duration of antibiotic treatment of meningitis needs to be more carefully assessed.