How it is administered

Trametinib is available as oral tablets (0.5 mg and 2 mg) and as an oral solution (0.05 mg/mL after reconstitution). It is taken by mouth once daily, usually on an empty stomach (at least 1 hour before or 2 hours after a meal). The dose may be adjusted based on body weight in children or for side effects.

How it works

Trametinib is a targeted therapy that works by blocking specific proteins called MEK1 and MEK2, which are part of the MAPK/ERK pathway. This pathway is involved in cell growth and division. In some cancers, including certain blood cancers, mutations in genes like BRAF can cause this pathway to be overactive, leading to uncontrolled cell growth.

By inhibiting MEK1 and MEK2, trametinib helps to slow down or stop the growth of cancer cells that rely on this pathway. It is especially effective in tumors with BRAF V600 mutations, which are known to activate the MAPK/ERK pathway. Trametinib is often used in combination with other targeted therapies to improve its effectiveness and reduce the risk of resistance developing.

Who Should take it

Trametinib is indicated for patients with certain cancers that have a BRAF V600E or V600K mutation, as detected by an FDA-approved test. It is used as a single agent or in combination with dabrafenib for:

• Unresectable or metastatic melanoma
• Metastatic non-small cell lung cancer (NSCLC)
• Locally advanced or metastatic anaplastic thyroid cancer
• Unresectable or metastatic solid tumors with BRAF V600E mutation (when no satisfactory alternative treatment options exist)
• Pediatric patients with low-grade glioma with BRAF V600E mutation

For blood cancers like Hairy Cell Leukemia, trametinib is not a standard treatment, but it may be considered in rare cases if the cancer has a BRAF V600E mutation and other options are not suitable.

Who should not take it

Trametinib should not be taken by patients who do not have a BRAF V600E or V600K mutation, as it is unlikely to be effective. It is not indicated for patients with colorectal cancer due to known resistance.

Women who are pregnant or may become pregnant should avoid trametinib, as it can cause harm to the unborn baby. Patients with severe allergic reactions to trametinib or any of its ingredients should not take it. Caution is also advised in patients with significant heart, lung, or eye problems, as trametinib can worsen these conditions.

Commonly used with

Trametinib is most commonly used in combination with dabrafenib, another targeted therapy that inhibits the BRAF protein. This combination is more effective than either drug alone for cancers with BRAF V600 mutations.

It may also be used alongside supportive medications to manage side effects, such as antipyretics for fever or antihypertensives for blood pressure control.

Commonly tested with

Trametinib is frequently tested in clinical trials with dabrafenib for various cancers with BRAF mutations. It has also been studied with other targeted therapies and chemotherapy agents in solid tumors.

For blood cancers, research is ongoing to determine the best combinations, but trametinib is not routinely tested with standard Hairy Cell Leukemia treatments.