These drugs target parts of skin cancer cells that make them different from normal skin cells. Targeted drugs work differently from standard chemotherapy drugs. They may work sometimes when chemotherapy drugs don’t. They can also have different (and sometimes less severe) side effects. Doctors are still learning the best way to use these drugs to treat skin cancers.
Hedgehog pathway inhibitors
Vismodegib (Erivedge) and sonidegib (Odomzo) are targeted drugs that can be used to treat some advanced or recurrent basal cell skin cancers.
It’s very rare for basal cell cancers to reach an advanced stage, but if they do, these cancers can be hard to treat. Most basal cell cancers have mutations (changes) in genes that are part of a cell signaling pathway called hedgehog. (Cell signaling pathways are how a cell gives instructions from one part of the cell to another, or to other cells.) The hedgehog pathway is crucial for the development of the embryo and fetus and is important in some adult cells, but it can be overactive in basal cell cancer cells, helping them grow. These drugs target a protein in this pathway.
These drugs are capsules taken once a day. For basal cell cancers that have spread or come back after surgery or other local treatments, these drugs have been shown to help shrink tumors in some people, although it’s not yet clear if they help people live longer.
Side effects can include muscle spasms, joint pain, hair loss, fatigue, problems with taste, poor appetite and weight loss, nausea and vomiting, itchy skin, diarrhea, and constipation. These drugs can also cause women to stop having their periods.
Because the hedgehog pathway affects fetal development, these drugs should not be taken by women who are pregnant or could become pregnant. It is not known if they could harm the fetus if taken by a male partner. Anyone taking these drugs should use reliable birth control during and for some time after treatment.
Squamous cell skin cancer cells often have too much of a protein called EGFR on their surfaces, which can help them grow. Drugs that target this protein, such cetuximab (Erbitux), have been shown to shrink some of these cancers in early studies. Although the evidence for their use so far is limited, they might be helpful for some people.
Side effects of EGFR inhibitors can include:
- Skin problems
- Mouth sores
- Loss of appetite
Skin problems can include an acne-like rash on the face and chest, which in some cases can lead to skin infections.