BACKGROUND & AIMS Monitoring serum concentrations of tumor necrosis factor antagonists in patients receiving these drugs as treatment for inflammatory bowel disease (IBD), also called therapeutic drug monitoring, is performed either after patient loss of response (reactive drug monitoring) or in patients in clinical remission whose drug has been titrated to a target concentration (proactive drug monitoring). We compared long-term outcomes of patients with IBD undergoing proactive vs reactive monitoring of serum concentrations of infliximab. METHODS We performed a multicenter, retrospective study of 264 consecutive patients with IBD (167 with Crohn’s disease) receiving infliximab maintenance therapy. The subjects received proactive (n = 130) or reactive (n = 134) drug monitoring, based on measurements of first infliximab concentration and antibodies to infliximab, from September 2006 to January 2015; they were followed through December 2015 (median time of 2.4 years). We analyzed time to treatment failure, first IBD-related surgery or hospitalization, serious infusion reaction, and detection of antibodies to infliximab. Treatment failure was defined as drug discontinuation for loss of response or serious adverse event, or need for surgery. RESULTS Multiple Cox regression analysis independently associated proactive drug monitoring, compared with reactive monitoring, with reduced risk for treatment failure (hazard ratio [HR], 0.16; 95% confidence interval [CI], 0.09–0.27; P < .001), IBD-related surgery (HR, 0.30; 95% CI, 0.11–0.80; P = .017), IBD-related hospitalization (HR, 0.16; 95% CI, 0.07–0.33; P < .001), antibodies to infliximab (HR, 0.25; 95% CI, 0.07–0.84; P = .025), and serious infusion reaction (HR, 0.17; 95% CI, 0.04–0.78; P = .023). CONCLUSIONS In a retrospective analysis of patients with IBD receiving proactive vs reactive monitoring of serum concentration of infliximab, proactive monitoring was associated with better clinical outcomes, including greater drug durability, less need for IBD-related surgery or hospitalization, and lower risk of antibodies to infliximab or serious infusion reactions.

α-Particles are suitable to treat cancer micrometastases because of their short range and very high linear energy transfer. α-Particle emitter 213 Bi-based radioimmunotherapy has shown efficacy in a variety of metastatic animal cancer models, such as breast, ovarian, and prostate cancers. Its clinical implementation, however, is challenging due to the limited supply of 225 Ac, high technical requirement to prepare radioimmunoconjugate with very short half-life (T 1/2 = 45.6 min) on site, and prohibitive cost. In this study, we investigated the efficacy of the α-particle emitter Ac (400 nCi)-labeled anti-rat HER-2/neu monoclonal antibody (7.16.4) completely eradicated breast cancer lung micrometastases in ∼67% of HER-2/neu transgenic mice and led to long-term survival of these mice for up to 1 year. Treatment with 225 Ac-7.16.4 is significantly more effective than 213 Bi-7.16.4 (120 μCi; median survival, 61 days; P = 0.001) and 90 Y-7.16.4 (120 μCi; median survival, 50 days; P < 0.001) as well as untreated control (median survival, 41 days; P < 0.0001). Dosimetric analysis showed that 225 Ac-treated metastases received a total dose of 9.6 Gy, significantly higher than 2.0 Gy from 213 Bi and 2.4 Gy from 90 Y. Biodistribution studies revealed that 225 Ac daughters, 221 Fr and 213 Bi, accumulated in kidneys and probably contributed to the long-term renal toxicity observed in surviving mice. These data suggest 225 Ac-labeled anti-HER-2/neu monoclonal antibody could significantly prolong survival in HER-2/neu-positive metastatic breast cancer patients. [Cancer Res 2009;69(23):8941-8]

This study showed that proactive infliximab monitoring following reactive testing was associated with greater drug persistence and fewer IBD-related hospitalizations than reactive testing alone.

The expanding clinical challenge of respiratory tract infections due to resistant bacteria necessitates the development of new forms of therapy. The development of a compound composed of silver coupled to a methylated caffeine carrier (silver carbene complex 1 [SCC1]) that demonstrated in vitro efficacy against bacteria, including drug-resistant organisms, isolated from patients with respiratory tract infections was described previously. The findings of current in vitro studies now suggest that bactericidal concentrations of SCC1 are not toxic to airway epithelial cells in primary culture. Thus, it was hypothesized that SCC1 could be administered by the aerosolized route to concentrate delivery to the lung while minimizing systemic toxicity. In vivo, aerosolized SCC1 delivered to mice resulted in mild aversion behavior, but it was otherwise well tolerated and did not cause lung inflammation following administration over a 5-day period. The therapeutic efficacy of SCC1 compared to that of water was shown in a 3-day prophylaxis protocol, in which mice infected with a clinical strain of Pseudomonas aeruginosa had increased survival, decreased amounts of bacteria in the lung, and a lower prevalence of bacteremia. Similarly, by using an airway infection model in which bacteria were impacted in the airways by agarose beads, the administration of SCC1 was significantly superior to water in decreasing the lung bacterial burden and the levels of bacteremia and markers of airway inflammation. These observations indicate that aerosolized SCC1, a novel antimicrobial agent, warrants further study as a potential therapy for bacterial respiratory tract infections.

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