Treatment of malignant ascites with a second cycle of catumaxomab in gastric signet cell carcinoma--a report of 2 cases

Engineered Bifunctional Proteins for Targeted Cancer Therapy: Prospects and Challenges

Bifunctional proteins (BFPs) are a class of therapeutic agents produced through genetic engineering and protein engineering, and are increasingly used to treat various human diseases, including cancer. These proteins usually have two or more biological functions-specifically recognizing different molecular targets to regulate the related signaling pathways, or mediating effector molecules/cells to kill tumor cells. Unlike conventional small-molecule or single-target drugs, BFPs possess stronger biological activity but lower systemic toxicity. Hence, BFPs are considered to offer many benefits for the treatment of heterogeneous tumors. In this review, the authors briefly describe the unique structural feature of BFP molecules and innovatively divide them into bispecific antibodies, cytokine-based BFPs (immunocytokines), and protein toxin-based BFPs (immunotoxins) according to their mode of action. In addition, the latest advances in the development of BFPs are discussed and the potential limitations or problems in clinical applications are outlined. Taken together, future studies need to be centered on understanding the characteristics of BFPs for optimizing and designing more effective such drugs.

Discovery and characterization of COVA322, a clinical-stage bispecific TNF/IL-17A inhibitor for the treatment of inflammatory diseases

Biologic treatment options such as tumor necrosis factor (TNF) inhibitors have revolutionized the treatment of inflammatory diseases, including rheumatoid arthritis. Recent data suggest, however, that full and long-lasting responses to TNF inhibitors are limited because of the activation of the pro-inflammatory T_H17/interleukin (IL)-17 pathway in patients. Therefore, dual TNF/IL-17A inhibition is an attractive avenue to achieve superior efficacy levels in such diseases. Based on the marketed anti-TNF antibody adalimumab, we generated the bispecific TNF/IL-17A-binding FynomAb COVA322. FynomAbs are fusion proteins of an antibody and a Fyn SH3-derived binding protein. COVA322 was characterized in detail and showed a remarkable ability to inhibit TNF and IL-17A in vitro and in vivo. Through its unique mode-of-action of inhibiting simultaneously TNF and the IL-17A homodimer, COVA322 represents a promising drug candidate for the treatment of inflammatory diseases. COVA322 is currently being tested in a Phase 1b/2a study in psoriasis (ClinicalTrials.gov Identifier: NCT02243787).

A phase I trial of intravenous catumaxomab: a bispecific monoclonal antibody targeting EpCAM and the T cell coreceptor CD3

PURPOSE

The aim of the study was to evaluate the safety and determine the maximum tolerated dose (MTD) of intravenous catumaxomab, a trifunctional bispecific antibody that binds to EpCAM on epithelial cancer cells and CD3 on T cells.

METHODS

The trial was a dose-escalation study with a 3 + 3 design in epithelial cancers with known EpCAM expression. The dose-limiting toxicity (DLT) period consisted of 4 weeks, with weekly intravenous administration of catumaxomab. Key DLTs were ≥grade 3 optimally treated non-hematological toxicity; ≥grade 3 infusion-related reactions refractory to supportive care; ≥grade 3 increase in liver enzymes and/or bilirubin not resolving to grade 2.

RESULTS

Sixteen patients were enrolled receiving doses of 2 (n = 5), 4 (n = 3), 7 (n = 7) and 10 µg catumaxomab (n = 1). The most common treatment-emergent adverse events (TEAEs) were chills (93.8 %) and pyrexia (87.5 %). The most common TEAE of grade ≥3 was transient dose-dependent increases in aspartate aminotransferase (56.3 %). The intensity of toxicities decreased with the number of infusions. Also, serum IL-6 increased in a dose-dependent manner and reverted to low or undetectable levels after four infusions. A reversible decrease in liver function test (prothrombin time) at the 7-µg dose level was considered a DLT. The first patient at 10 µg experienced a fatal hepatic failure related to catumaxomab that led to the termination of the study.

CONCLUSIONS

The MTD of weekly intravenous catumaxomab was 7 µg. Major toxicities were cytokine release-related symptoms and hepatotoxicity.