Clinical Trials for HER2 Mutant-Positive Tumors

Clinical Trials for HER2 (human epidermal growth factor receptor 2) Mutant-Positive Tumors are studies in which new treatments are being evaluated for their safety and efficacy for cancer patients. For new cancer therapies to be commercially used and known as a standard of care, they must be approved by the FDA after evaluation in different phases of clinical trials. These trials both help patients access new treatments and further clinical research with their participation.

The HER2 is a protein on the surface of cells that regulates growth. If there are more HER2 proteins than normal, cells will grow and spread rapidly. Therefore, in HER2 positive cancer cases, the cancerous cells will be more aggressive than normal and spread at a quicker rate. This can lead to a worsening prognosis for HER2 positive patients regardless of their cancer type. Changes in HER2 occurs in several cancer types, but most commonly in breast cancer. HER2 mutations also occur in:

• Pancreatic cancer
• Bladder cancer
• Ovarian cancer
• Stomach cancer

Clinical Trials for HER2 Positive Tumors

Clinical Trials for HER2 Mutant-Positive Tumors not only evaluate new therapies, but also new methods of prevention and diagnostics. The more we understand about HER2 tumors and how they affect the cancer prognosis, the more effectively researchers will be able to treat them. Clinical trials have developed many targeted therapies that target the HER2 proteins. Doing so will inhibit these cells from their aggressive growth and reproduction. Also, healthy cells without the HER2 protein will be avoided, which may cause less side effects compared to standard therapies.

Targeted therapies approved for breast cancer treatment:

• Enhertu (fam-trastuzumab-deruxtecan-nxki)
• Herceptin (trastuzumab)
• Kadcyla (T-DM1 or ado-trastuzumab emtansine)
• Nerlynx (neratinib)
• Perjeta (pertuzumab)
• Tykerb (lapatinib)

Although the above therapies have been approved specifically for breast cancer, some of them are used for other cancer types as well. There are 35 clinical trials for HER2 cancers around the United States. These trials evaluate the use of new drugs in hopes they will be approved by the FDA. These trials are available for any patients with HER2 positive cancer who meet the eligibility criteria. Talk to your doctor to see if you could benefit from clinical trial therapies.

How to Test for HER2

Testing positive for HER2 or other gene mutations will reveal how the mutation is influencing the behavior and growth of the cancer cells, as well as which treatments the patient will be resistant or responsive to. There are two main types of testing for cancer patients who want to know if they are HER2 positive, they are:

IHC test (ImmunoHistoChemistry): Chemical dye is used to mark the HER2 proteins present in a tissue sample. If the score is 0 or 1, the test result is considered negative. A score of 2 is borderline, and anything over 3 is considered positive.

FISH test (Fluorescence In Situ Hybridization): Special labels are used that attach to each HER2 protein. Once attached, the label will turn a different color to indicate HER2 is present. This testing method is more expensive and can take more time to finalize results, but it is the most accurate. In fact, many patients who show borderline results from the IHC test, will confirm the results with a FISH test. The results for this test are a positive or negative.

To be considered for HER2 targeted therapies, patients will either need a 3+ score on the IHC test, or a positive result from the FISH test. If the score is any lower, targeted drugs will most likely not be as effective as standard treatments such as chemotherapy or radiation therapy. Speak with your doctor if you are interested in testing to confirm the presence of the HER2 mutation.

Sources:

https://www.breastcancer.org/symptoms/diagnosis/her2

https://www.cancer.gov/publications/dictionaries/cancer-terms/def/her2-positive