Treating vestibular schwannoma with chemotherapy and biologics
Chemotherapy and biologics are emerging as potential treatment options for vestibular schwannoma, a benign tumour affecting the inner ear’s vestibular nerve. While surgery and radiation have traditionally been the go-to treatments for vestibular schwannomas, they are often associated with significant side effects and a risk of hearing loss. As our understanding of the genetic factors and aggressive nature of vestibular schwannomas in conditions like neurofibromatosis type 2 (NF2) has grown, there is increasing interest in exploring medical treatments as an alternative to traditional interventions (1,2,3).
Chemotherapy is not yet considered a standard treatment for vestibular schwannomas.
Chemotherapy for vestibular schwannoma
Chemotherapy, which involves the use of drugs to target and kill cancer cells, is not yet considered a standard treatment for vestibular schwannomas (4). However, ongoing research is investigating the potential of using chemotherapy to treat these tumours, particularly in patients with NF2 who may have multiple tumours that are difficult to manage surgically or with radiation. By targeting the cells responsible for tumour growth, chemotherapy can slow down or even eliminate vestibular schwannomas without the need for invasive procedures.
Biologics in vestibular schwannoma
Biologics are complex substances from living organisms, such as proteins, sugars, and nucleic acids (5). They are used to treat various medical conditions, including autoimmune diseases, cancer, and inflammatory disorders. Biologics are typically more targeted and effective than traditional small-molecule drugs. They are often administered via injection or infusion and are customized to interact with specific cellular or molecular targets in the body. In the case of vestibular schwannoma, biologics can specifically target and inhibit the growth of the tumour cells.
Challenges with biologics and chemotherapy
Determining the optimal treatment endpoints is a crucial challenge in developing chemotherapy for vestibular schwannomas. Should the goal be to stop tumour growth, reduce tumour size, or maintain hearing and vestibular function? Since many patients with NF2 are young and may require long-term treatment, understanding the potential long-term side effects of chemotherapy is also critical. Balancing the benefits of therapy with the risks of chronic side effects is a key consideration in developing effective chemotherapy protocols for vestibular schwannomas.
Bevacizumab and Erlotinib for vestibular schwannoma
Two drugs that are currently under investigation for the treatment of vestibular schwannomas are bevacizumab and Erlotinib.
Bevacizumab is a monoclonal antibody that targets and inhibits the activity of vascular endothelial growth factor (VEGF). VEGF is a protein that promotes the growth of new blood vessels, which are essential for tumour growth and survival (6, 7). By blocking VEGF, bevacizumab can slow down or shrink the tumour in patients with vestibular schwannoma. Bevacizumab has effectively halted tumour growth and prevented hearing loss in certain NF2 patients with vestibular schwannomas. Despite its benefits, many patients may encounter severe side effects. Therefore, it is advised to use bevacizumab cautiously for symptom relief in NF2 patients with vestibular schwannomas.
Erlotnib targets the growth of Schwann cells, which are the cells responsible for developing vestibular schwannomas. By inhibiting these cells’ growth, Erlotinib can halt tumour progression and shrink existing tumours (8).
Other biologics in vestibular schwannoma
Other biologics, such as mTOR or immune checkpoint inhibitors, may also treat vestibular schwannoma by targeting different pathways or mechanisms involved in tumour growth (9). These medications are often used in combination with surgery or radiation therapy to treat the tumour and prevent a recurrence effectively.
Research in vestibular schwannoma chemotherapy and biologics
Research centres in Massachusetts, USA, and other locations are actively studying the use of chemotherapy and biologics in treating vestibular schwannomas (10). By exploring the potential of these medical treatments, researchers hope to develop more effective and less invasive treatment options for patients with vestibular schwannomas, particularly those with NF2. As our understanding of the molecular pathways involved in tumour growth and progression continues to advance, the potential for targeted therapies like chemotherapy to revolutionize the treatment of vestibular schwannomas is becoming increasingly promising.
The future of chemotherapy and biologics in vestibular schwannoma
Ongoing research in chemotherapy and biologics is shedding light on its potential as a viable alternative to surgery and radiation (11). By targeting the cells responsible for tumour growth, chemotherapy can slow down or even eliminate vestibular schwannomas, particularly in patients with NF2 who may have multiple tumours that are difficult to manage surgically. With promising drugs like bevacizumab and Erlotinib showing efficacy in early studies, the future of chemotherapy and biologics in vestibular schwannoma treatment holds great promise for patients seeking less invasive and more targeted treatment options.