By Nicole Ross, CRNP, MSN, AOCNP®

Targeted therapies block the growth of cancer by interfering with specific molecules and may also be referred to as molecularly targeted drugs or precision oncology. Advanced practice RNs (APRNs) must be familiar with the various agents and their side effect profiles, including immunotherapies, hormone therapies, apoptosis inducers, monoclonal antibodies, angiogenesis inhibitors, and signal transduction inhibitors. 

Understanding Targeted Therapies

Use of a targeted therapy may be restricted to patients whose tumors have a specific gene mutation that codes for the target; patients who do not have the mutation would not be candidates for that particular therapy because it would have nothing to target. For example, epidermal growth factor receptor (EGFR) plays an important role in metastatic colorectal cancer growth and has become a promising target for treatment options. Only patients without a RAS mutation (known as RAS wild-type) may benefit from anti-EGFR therapy, including cetuximab or panitumumab. APRNs should be familiar with this to educate patients about their treatment plan.

Targeted therapies’ limitations include resistance or the development of new pathways. Mutations can change over time and may be a reason to consider additional genetic testing in the future. 

Providing Patient Education and Support

The APRN’s role in providing patient education is especially important because many targeted agents are administered orally. Ask patients to verify how they are taking their medication and confirm adherence. Patients should be instructed on proper timing of medication and schedules; consider giving them a printed calendar and list of expected side effects, as well as information about how to prevent or manage those side effects. 

APRNs should conduct a thorough medication review to identify drug interactions, as well as validate whether patients have appropriate home supervision when needed to ensure compliance. 

Managing Adverse Events

Expected side effects vary depending on the targeted agent. For example, with EGFR inhibitors, acne-like rash and diarrhea are the most common side effects. However, with another class of targeted agents such as the tyrosine kinase inhibitors, expected side effects differ and may include hypertension, diarrhea, abnormal liver function tests, or hand-foot syndrome. It is therefore crucial to understand the pathophysiology to properly assess and manage toxicities. 

Some available resources for APRNs in managing differing classes of medications include information from ONS, UpToDate, Medscape, and the medication’s package insert. Individual drug websites may also be a helpful resource for providers and patients.  Additionally, new ONS quality measures are available to measure assessment for and management of immune-related adverse events during cancer treatment with checkpoint inhibitors. Contact ONS staff at research@ons.org for more information.

APRNs should also have an awareness of drug costs, especially for oral medications, and may require frequent communication with a specialty pharmacist. Patient assistance for copays may sometimes be available through the manufacturer or charitable organizations such as Good Days. Some specialty pharmacies also have authorization specialists who navigate the authorization process with the insurance and the provider to obtain prompt authorization, which is key in oncology.