Affibody PET Imaging of HER2-Expressing Cancers as a Key to Guide HER2-Targeted Therapy.

Human epidermal growth factor receptor 2 (HER2) is a major prognostic and predictive marker overexpressed in 15-20% of breast cancers. The diagnostic reference standard for selecting patients for HER2-targeted therapy is based on the analysis of tumor biopsies. Previously patients were defined as HER2-positive or -negative; however, with the approval of novel treatment options, specifically the antibody-drug conjugate trastuzumab deruxtecan, many breast cancer patients with tumors expressing low levels of HER2 have become eligible for HER2-targeted therapy. Such patients will need to be reliably identified by suitable diagnostic methods. Biopsy-based diagnostics are invasive, and repeat biopsies are not always feasible. They cannot visualize the heterogeneity of HER2 expression, leading to a substantial number of misdiagnosed patients. An alternative and highly accurate diagnostic method is molecular imaging with radiotracers. In the case of HER2, various studies demonstrate the clinical utility and feasibility of such approaches. Radiotracers based on Affibody® molecules, small, engineered affinity proteins with a size of ~6.5 kDa, are clinically validated molecules with favorable characteristics for imaging. In this article, we summarize the HER2-targeted therapeutic landscape, describe our experience with imaging diagnostics for HER2, and review the currently available clinical data on HER2-Affibody-based molecular imaging as a novel diagnostic tool in breast cancer and beyond.

GP2015, a proposed etanercept biosimilar: Pharmacokinetic similarity to its reference product and comparison of its autoinjector device with prefilled syringes.

AIMS: To assess pharmacokinetics (PK) and safety of GP2015, a proposed etanercept biosimilar, in two studies: comparison with etanercept originator (ETN, bioequivalence study) and comparison of GP2015 administered via an autoinjector (AI) or prefilled syringes (PFS, delivery study). METHODS: Both studies were randomized, two-sequence, two-period, crossover studies conducted in healthy male subjects. In the bioequivalence study, subjects were randomized to receive a single 50 mg subcutaneous (s.c.) injection of GP2015 or ETN. In the delivery study, subjects were randomized to receive a single 50 mg s.c. injection of GP2015 via AI or PFS. Following a wash-out period of 35 days, subjects in the bioequivalence study received single 50 mg s.c. injection of GP2015 or ETN, and subjects in the delivery study received single 50 mg s.c. injection of GP2015 via AI or PFS. RESULTS: The geometric mean ratios (90% confidence interval) of GP2015/ETN for Cmax (1.11 [1.05-1.17]), AUC0-tlast (0.98 [0.94-1.02]) and AUC0-inf (0.96 [0.93-1.00]) were within the predefined bioequivalence range of 0.80-1.25. The geometric mean ratios (90% confidence interval) of AI/PFS for Cmax (1.01 [0.94-1.08]), AUC0-tlast (1.01 [0.95-1.07]) and AUC0-inf (1.01 [0.96-1.07]) were also within the range 0.80-1.25. No new safety issues were reported. Three subjects had low titres of non-neutralising anti-drug antibodies during a follow-up visit in the bioequivalence study. CONCLUSIONS: The PK of GP2015 was similar to ETN, demonstrating bioequivalence. The safety profile of GP2015 was consistent with previous reports for ETN. The GP2015 AI provided equivalent dosing and tolerability to the GP2015 PFS.