Risk Minimization of Antibody-Drug Conjugates in Oncology: A Review.

Antibody-drug conjugates (ADCs) are new treatment options for certain cancers, especially those in advanced states with limited treatment options. Their unique design provides targeted therapy with toxins that otherwise would not be available, but they manifest toxicities that require risk minimization interventions to optimize their tolerability. We summarize selected toxicities for ADCs that have been approved through the end of 2020 and three investigational ADCs, which include both payload and linker, as described in the US Prescribing Information, the European Summary of Product Characteristics, and study protocols. These toxicities include peripheral neuropathy; pulmonary, skin, hepatic, and ocular toxicities; hyperglycemia; left ventricular dysfunction; and fluid-related events. We also review the risk minimization approaches to managing these toxicities as described in the product labels and study protocols. Our general observation suggests that the selected toxicities of the approved ADCs are primarily associated with off-target effects of the drug payloads. We also observed that the risk minimization approaches used to manage the selected toxicities are similar across product labels and study protocols. ADCs provide a unique treatment approach that is currently focused on advanced or refractory cancers. The risk minimization approaches for the selected toxicities for the approved ADCs per product label, or the study protocol for those in clinical investigation, are similar to those of standard chemotherapy agents and other pharmaceutical agents for the treatment of advanced malignancies. These risk minimization measures align with standard medical practice and are likely familiar to and feasible for physicians who prescribe for, and to other healthcare practitioners who care for, patients treated with ADCs.

Lack of evidence of measles virus shedding in people with inapparent measles virus infections.

Serological evidence of measles virus infection has been detected among people exposed to measles who do not exhibit classical clinical symptoms. Throat swabs, lymphocytes, and serum and urine samples were collected from contacts of individuals with confirmed measles 12-16 days after exposure, during measles outbreaks occurring in 1998. Follow-up serum samples were drawn 2 weeks later. Samples were tested for measles IgM antibody by enzyme immunoassays and plaque reduction neutralization testing. Virus isolation and reverse transcriptase-polymerase chain reaction testing was attempted for all samples. None of the 133 contacts developed classical measles disease; 11 (8%) had serological evidence of infection. Duration of exposure of >or=3 h was the only significant risk factor for developing serological response (24% vs. 4% among contacts exposed for 1-2 h; relative risk, 6.0; 95% confidence interval, 1.9-19.2). None of the 133 contacts had virological evidence of infection by culture or polymerase chain reaction. We found no evidence that persons with inapparent measles virus infections shed measles virus.

Issues associated with and recommendations for using PCR to detect outbreaks of pertussis.

Two outbreaks of respiratory tract illness associated with prolonged cough occurring in 1998 and 1999 in New York State were investigated. A PCR test for Bordetella pertussis was primarily used by a private laboratory to confirm 680 pertussis cases. Several clinical specimens had positive culture results for B. pertussis during both outbreaks, which confirmed that B. pertussis was circulating during the outbreaks. However, testing by the New York State Department of Health reference laboratory suggested that some of the PCR results may have been falsely positive. In addition, features of the outbreak that suggested that B. pertussis may not have been the primary agent of infection included a low attack rate among incompletely vaccinated children and a significant amount of illness among patients testing PCR negative for B. pertussis. These investigations highlight the importance of appropriate clinical laboratory quality assurance programs, of the limitations of the PCR test, and of interpreting laboratory results in context of clinical disease.