Vemurafenib (Zelboraf®; Roche), like most oral targeted therapies for cancer on the market has specific requirements for administration. Patients are instructed to swallow tablets whole without regard to food. Vemurafenib tablets contain a micro-precipitate powder specifically formulated to improve solubility and bioavailability. Tablets are film-coated to assist with ease of swallowing without affecting dissolution.
We report a case of a 38yo female with metastatic melanoma (BRAF V600E) who elected to crush and chew vemurafenib due to her severe phobia of swallowing tablets.
Lactate dehydrogenase (LDH), a marker useful in monitoring the course of melanoma was 2340U/L (usual range 120-225U/L) upon commencement of vemurafenib therapy. Two weeks later LDH reduced to 552U/L. After 4 weeks the level further reduced to 340U/L. The patient reported a marked clinical improvement in pain and mood with imaging suggesting a good response. The main reported side effect was a keratosis pilaris (KP) rash on the forehead and shoulder areas, a common side effect of vemurafenib therapy.
Six weeks after commencement of therapy the patient was admitted with severe nausea and vomiting. Vemurafenib was withheld for a period of 10 days resulting in an LDH rise from 375U/L to 3127U/L. With the improvement of her nausea, vemurafenib was recommenced, subsequently LDH reduced to 1000U/L. The patient was discharged home, however four weeks later she was readmitted with progressive disease and new brain metastases and she passed away one week later.
In this case, despite the patient administering vemurafenib against usual administration recommendations the therapy was initially controlling her disease. During the brief period the treatment was withheld, there appeared to be rapid disease progression. In summary, whilst we would not recommend it to all patients, we would suggest that, if absolutely necessary, patients may crush their vemurafenib tablets immediately prior to taking.