Investigation of pre-existing reactivity to biotherapeutics can uncover potential immunogenic epitopes and predict immunogenicity risk.

Despite recent advances in the development of tools to predict immunogenicity risk of biotherapeutic molecules, the ability of a protein to elicit the formation of anti-drug antibodies (ADA) remains one of the most common causes for termination of clinical development programs. In this study, we use ADA assays to detect and measure pre-existing reactivity or the ability of a molecule to produce an ADA-like response in serum from treatment-naïve, healthy donors. We report herein that the magnitude of pre-existing reactivity evaluated pre-clinically and expressed as the 90th percentile of Tier 2 inhibition correlates with the subsequent rate of ADA emergence in the clinic. Furthermore, a multi-domain biotherapeutic (IgG-scFv bispecific antibody) showed the highest pre-existing reactivity and incidence of treatment-emergent ADA (TE-ADA) (57% and 93%, respectively). Using the components of the multidomain molecule in the Tier 2 step of the ADA assay, we were able to identify the scFv as the target of the serum pre-existing reactivity. Most importantly, the domain specificity of pre-existing ADA was the same as that of the TE-ADA from patients treated with the molecule. Based on these data, we propose the evaluation of the magnitude and of the domain specificity of pre-existing reactivity as a powerful tool to understand the immunogenic potential of novel biotherapeutics.

Cancer- and chemotherapy-induced anemia.

Anemia is prevalent in 30% to 90% of patients with cancer. Anemia can be corrected through either treating the underlying cause or providing supportive care through transfusion with packed red blood cells or administration of erythropoiesis-stimulating agents (ESAs), with or without iron supplementation. Recent studies showing detrimental health effects of ESAs sparked a series of FDA label revisions and a sea change in the perception of these once commonly used agents. In light of this, the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Cancer- and Chemotherapy-Induced Anemia underwent substantial revisions this year. The purpose of these NCCN Guidelines is twofold: 1) to operationalize the evaluation and treatment of anemia in adult cancer patients, with an emphasis on those who are receiving concomitant chemotherapy, and 2) to enable patients and clinicians to individualize anemia treatment options based on patient condition.

Guidelines for the use of erythropoietic growth factors in patients with chemotherapy-induced anemia.

The use of erythropoietic growth factors to treat chemotherapy-induced anemia (CIA) has been increasing as clinicians become more aware of the ability of these drugs to improve the quality of life of patients with cancer. The cost associated with erythropoietic growth factor therapy makes its appropriate use a practical issue for physicians and hospitals. Clinical practice guidelines can benefit physicians by increasing practice efficiency, reducing medical errors, increasing the quality of medical care, and decreasing reimbursement problems. The American Society of Clinical Oncology and the American Society of Hematology, the European Organisation for Research and Treatment of Cancer, and the National Comprehensive Cancer Network (NCCN) have all published guidelines for using erythropoietic growth factors to treat CIA, and this article reviews and summarizes those guidelines. Of the three guidelines for the use of erythropoietic growth factors in CIA, the NCCN guidelines are based on the most recent data. Current evidence indicates that erythropoietic growth factors can increase hemoglobin levels, reduce the need for red blood cell transfusions, and improve quality of life; the effect of erythropoietic therapy on outcomes in patients with CIA is still being investigated.