Combination radioimmunotherapy is an emerging approach for the treatment of solid tumors where radio immunotherapy alone has proven to be reasonably ineffective. Radioimmunotherapy (RIT) using monoclonal antibodies (mAbs) labeled with radionuclides is an attractive approach for cancer treatment because tumor-associated mAbs with cytotoxic radionuclides can selectively bind to tumor antigens. However, due to various limitations, mAbs cannot reach solid tumors, consequently reducing RIT efficacy. Combination RIT is a pragmatic approach through which the addition of drugs or other agents not only help mAbs to reach the targeted site but also improves its efficacy. Thus, the combination of drugs or moieties with RIT can be applied to overcome the barriers that RIT faces for solid tumors. This review covers the RIT approach, along with the mechanism of action of mAb used in RIT, limitations of solid tumors, and strategies that can be used in combination RIT to enhance the treatment regimen for solid tumors.

Organic nanomaterials, as nanocarrier platforms, have tremendous potential for biomedical applications. The authors successfully prepared novel two‐dimensional covalent organic nanosheets (CONs) that can be used as efficient in vivo bioimaging probes by condensing 1,3,5‐triformylglucinol (Tp) and 2,7‐diaminopyrene (Py) to produce TpPy covalent organic frameworks (COFs). TpPy COFs are then subjected to a liquid exfoliation process to obtain TpPy CONs (< 200 nm in size and < 1.7 nm in thickness). TpPy CONs disperse well in water to provide a stable, homogeneous colloidal suspension, which shows favorable photoluminescence properties. Cell viability tests using MDA‐MB‐231 and RAW 264.7 cells reveal that TpPy CONs are low in cytotoxicity. Confocal microscopy reveals clear fluorescent cell images after incubation with TpPy CONs for 24 h, without reduction in cell activity or cytosolic aggregation. To investigate the biological behavior of the TpPy CONs, the authors perform an in vivo fluorescence imaging study using MDA‐MB‐231 tumor‐bearing mice. After intravenous injection of TpPy CONs disperse in phosphate‐buffered saline (PBS), persistent and strong fluorescence signals are observed in the tumor region, with low background signals from normal tissues at 1, 3, 12, and 24 h after injection. Furthermore, these in vivo imaging results concurred with ex vivo biodistribution and histological results.

The authors identified that chemo-brain was induced after trastuzumab (TZB) therapy. In addition, atorvastatin (ATV) could rescue chemo-brain during trastuzumab (TZB) therapy. Enhanced therapeutic effect of TZB was confirmed after ATV therapy. We also investigated that there was no hair loss side effect due to ATV therapy. In an animal model, 150 μg TZB and five serial doses of 20 mg/kg ATV were administered. ¹⁸F-fluorodeoxyglucose Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) data were acquired. Statistical parametric mapping analysis and voxel-based morphometry analysis were performed to identify differences in glucose metabolism and gray matter concentration. The enhanced therapeutic efficacy of TZB after ATV treatment was assessed using a human epidermal growth factor receptor 2-positive gastric cancer model. We found a decrease in cerebral glucose metabolism and gray matter concentration in the frontal lobe following TZB therapy (p < 0.005). After subsequent ATV administration, glucose metabolism and regional gray matter concentration were rescued (p < 0.005). Cognitive impairment due to TZB and the rescue effect of ATV were confirmed using a passive avoidance test and quantitative real-time reverse transcription PCR. Furthermore, the penetration and accumulation of TZB in tumors increased by 100% after ATV co-administration, which resulted in an enhanced anti-cancer effect. Our study collectively demonstrates that ATV co-administration with TZB rescued the TZB-induced chemo-brain and enhances the therapeutic efficacy of TZB in tumors. We also showed that there was no hair loss during ATV therapy.