High-expression EGFR/cell membrane chromatography-online-high-performance liquid chromatography/mass spectrometry: rapid screening of EGFR antagonists from Semen Strychni

RATIONALE

Traditional methods for screening active compounds from complex system such as traditional Chinese medicines are relatively cumbersome and time-consuming. In order to improve this situation, we established an online analytical method for screening, separation and identification EGFR antagonists from traditional Chinese medicines, which is described in this study.

METHODS

Cells with high EGFR expression levels were used to prepare the cell membrane stationary phase for the EGFR cell membrane chromatography model with the purpose of screening active compounds. Separation of the retention fractions was achieved by the high-performance liquid chromatography, and identification was conducted via electrospray ionization quadrupole mass spectrometry. The inhibitory effects of active compounds on EGFR cell growth were also demonstrated in vitro.

RESULTS

The screening results showed that vauquline and strychnine from Semen Strychni could be active components acting on EGFR similarly to gefitinib as a control drug. Results from biological trials showed that vauquline and strychnine inhibited cell proliferation of HEK293/EGFR cells, and inhibited Erk phosphorylation, and can effectively reduce expression of downstream signaling molecules.

CONCLUSIONS

This EGFR cell membrane chromatography-online-high-performance liquid chromatography/tandem mass spectrometry method can be applied for rapid screening, separation and identification of EGFR antagonists from traditional Chinese medicines and should be useful for drug discovery with natural medicinal herbs.

A dose-escalation phase I trial of nimotuzumab, an antibody against the epidermal growth factor receptor, in patients with advanced solid malignancies

PURPOSE

Nimotuzumab is a humanized monoclonal antibody which inhibits the ligand-dependent activation of epidermal growth factor receptor (EGFR). We conducted a phase I trial to assess the pharmacodynamic (PD) effects of escalating doses of nimotuzumab administered alone in patients with advanced solid cancers patients.

EXPERIMENTAL DESIGN

Patients were treated with escalating doses of weekly intravenous nimotuzumab at doses ranging between 100 and 800 mg. Tumor and skin biopsies were done before start of treatment and repeated 3 weeks after to assess immunohistochemical expression of EGFR and its downstream components.

RESULTS

Seventeen patients were enrolled, including 1 patient never treated. Although 1 dose-limiting-toxicity (DLT) was observed at 100 mg (grade 3 fatigue), nimotuzumab dose was escalated to 800 mg with no other DLT. No grade 4 toxicity was observed. Only 3 patients developed a grade 1 acneiform rash (18.7%). One patient achieved a partial response (6.2%) and 8 patients had stable disease (50.0%). The median TTP was 2.4 months. No significant changes in EGFR, AKT, ERK and Ki67 immuno-stainings were observed between pre- and on-treatment tumor or skin biopsies.

CONCLUSION

Nimotuzumab could be safety administered up to 800 mg with manageable toxicity. No relationships were found between pharmacodynamic effects on EGFR downstream signaling pathways and drug efficacy or toxicity.

Nimotuzumab: a novel anti-EGFR monoclonal antibody that retains anti-EGFR activity while minimizing skin toxicity

Due to the broad importance of EGFR to tumorogenesis, targeted therapy against it has rapidly developed into a novel paradigm for cancer treatment. Two promising classes of drugs are now in use and undergoing development that target this receptor: tyrosine kinase inhibitors (TKIs) and mAbs that inhibit EGFR's extracellular domain. Nimotuzumab, a humanized murine mAb created in Cuba, has demonstrated antitumor activity similar to that of other anti-EGFR mAbs and shows promise as a single agent and as an adjunct to radiation in Phase I and II clinical trials. Surprisingly, the typical severe dermatological toxicities thus far associated with anti-EGFR therapy have not been described with nimotuzumab. Here we summarize the background, development and characteristics of this new drug while reviewing the latest preclinical and clinical trial data that underpin its gradual adoption into clinical practice.