Summary Safety Review - Zelboraf (vemurafenib) - Assessing the Potential Risk of Bone Marrow Side Effects (Bone Marrow Toxicity or Suppression)

Review decision

A Summary Safety Review complements other safety related information to help Canadians make informed decisions about their use of health products. Each summary outlines what was assessed in Health Canada’s review, what was found and what action was taken by Health Canada, if any.


Issued: 2016-11-14

Product

Zelboraf (vemurafenib)

Potential Safety Issue

Bone marrow side effects (bone marrow toxicity or suppression)

Key Messages

  • Zelboraf is used in adult patients to treat an aggressive type of skin cancer (unresectable or metastatic melanoma). It works by targeting proteins made from a mutated gene called "BRAF".
  • Health Canada carried out a safety review after receiving a report from the manufacturer regarding the safety of Zelboraf.
  • Health Canada concluded that the evidence did not support a link between Zelboraf use and bone marrow side effects. Health Canada will continue to monitor safety information involving Zelboraf.

Overview

A safety review was carried out after receiving a report from the manufacturer regarding the potential for side effects related to the destruction (toxicity) or decreased production (suppression) of bone marrow cells in patients treated with Zelboraf.

Use in Canada

  • Zelboraf (vemurafenib) slows down or stops the growth of cancer cells by targeting specific proteins (proteins from the BRAF gene).
  • Zelboraf is used in adult patients to treat an aggressive type of skin cancer (unresectable or metastatic melanoma) that has a mutation in the BRAF gene and cannot be removed by surgery or has spread to other parts of the body.
  • Zelboraf has been marketed in Canada since March 2012.

Safety Review Findings

  • The bone marrow related side effects investigated during this safety review included very low levels of at least two types of blood cells, either red or white blood cells or platelets (bicytopenia or pancytopenia).
  • At the time of review, Health Canada had not received any Canadian reports of bone marrow related side effects in patients using Zelboraf.
  • The World Health Organization's Adverse Drug Reaction Database (VigiBase) had received 6 reports of side effects describing bone-marrow cell suppression (pancytopenia) suspected of being linked with the use of Zelboraf. The 6 reported cases were either incomplete or did not have enough information for further assessment.
  • A review of the scientific and medical literature did not find any articles or studies describing the development of bone marrow toxicity or suppression with Zelboraf.
  • Bone marrow side effects (toxicity or suppression) can occur in advanced metastatic melanoma patients from the use of other/previous chemotherapy treatments.
  • Although the report submitted to Health Canada by the manufacturer showed a potential for side effects related to bone marrow toxicity/suppression with Zelboraf use, further review by the manufacturer concluded that a link could not be established.

Conclusions and actions

  • Health Canada's safety review concluded that the current evidence available does not support a link between Zelboraf use and bone marrow toxicity or suppression.
  • Health Canada will continue to monitor safety information involving Zelboraf, as it does for all health products on the Canadian market, to identify and assess potential harms. Health Canada will take appropriate and timely actions when any new health risks are identified.

Additional information

The analysis that contributed to this safety review included scientific and medical literature, Canadian and international adverse reaction reports and what is known about the use of this drug both in Canada and internationally.

For additional information, contact the Marketed Health Products Directorate.