New Therapies in Head and Neck Cancer.

Head and neck squamous cell carcinoma (HNSCC) is a common malignancy with high rates of mortality and morbidity. Beginning with cetuximab, investigators continue to optimize antibody technology to target cell-surface receptors that promote HNSCC growth. Small molecules and oligonucleotides have also emerged as therapeutic inhibitors of key receptor-mediated signaling pathways. Although many such therapies have been disappointing in clinical trials as single agents, they continue to be studied in combination with standard therapies. Approvals of pembrolizumab and nivolumab opened a new era of immunotherapy that aims to stimulate antitumor immunity in the tumor microenvironment. Immunotherapies are being intensively investigated in new HNSCC clinical trials, with the goal of optimizing the therapeutic potential of this new class of anticancer agent.

Red colored IgG4 caused by vitamin B12 from cell culture media combined with disulfide reduction at harvest.

While many antibody therapeutics are formulated at low concentration (~10-20 mg/mL) for intravenous administration, high concentration (> 100 mg/mL) formulations may be required for subcutaneous delivery in certain clinical indications. For such high concentration formulations, product color is more apparent due to the higher molecular density across a given path-length. Color is therefore a product quality attribute that must be well-understood and controlled, to demonstrate process consistency and enable clinical trial blinding. Upon concentration of an IgG4 product at the 2000 L manufacturing scale, variability in product color, ranging from yellow to red, was observed. A small-scale experimental model was developed to assess the effect of processing conditions (medium composition and harvest conditions) on final bulk drug substance (BDS) color. The model was used to demonstrate that, for two distinct IgG4 products, red coloration occurred only in the presence of disulfide reduction-mediated antibody dissociation. The red color-causing component was identified as vitamin B 12, in the hydroxocobalamin form, and the extent of red color was correlated with the cobalt (vitamin B 12) concentration in the final pools. The intensity of redness in the final BDS was modulated by changing the concentration of vitamin B 12 in the cell culture media.