Opinion: A Case of Self-Experimentation with Oncolytic Virus Therapy Highlights the Need for More Research

Amanda Brink, DNP, APRN, FNP-BC, AOCNP

As an oncology nurse working in clinical trials, I value the structured process of enrolling patients in treatments with experimental drugs. This framework is designed to protect patients while helping researchers understand how new therapies work. However, when faced with tumor progression, some patients may seek out experimental treatments independently, even though this is typically discouraged by oncology teams. I can empathize with their desire to explore every possible option in the fight against cancer. In this article, we will highlight a case of self-experimentation and examine oncolytic virus therapy (OVT) as a potential treatment.

A Case of Neoadjuvant Oncolytic Virus Therapy in Breast Cancer

Forčić et al. recently reported a unique case of neoadjuvant OVT for a 50-year-old virologist with locally recurrent triple-negative breast cancer (TNBC), as described in Vaccines.¹ TNBC is notoriously difficult to treat because it lacks three key receptors—estrogen receptor (ER), progesterone receptor (PR), and Human Epidermal Growth Factor Receptor 2 (HER2)—that are typically targeted by conventional breast cancer therapies. This makes treatment options for TNBC limited and often less effective.²

The patient was initially diagnosed in 2016 and underwent a mastectomy followed by adjuvant chemotherapy. Two years later, she experienced a recurrence near the site of the mastectomy, which was surgically removed. However, a small seroma remained in the excision area, which was monitored over time. Two years later, imaging showed that this seroma had grown and invaded the pectoral muscle. A needle biopsy confirmed that the tumor had recurred, and interestingly, it had transformed from TNBC to HER2-positive breast cancer.¹

As an expert virologist with an in-depth understanding of OVT, the patient opted to pursue OVT prior to undergoing any other systemic treatments. Her oncology team was informed of her decision and offered their support.

The patient self-administered intratumoral (IT) injections of two viruses—a measles virus strain (MeV) and a vesicular stomatitis virus strain (VSV)—which she prepared in her laboratory. The OVT was well-tolerated and resulted in significant tumor reduction, enabling a successful surgical resection. Frequent imaging studies and clinical assessments confirmed that the tumor volume decreased from 2.47 cm³ at baseline to 0.91 cm³ by the time of surgery. Pathology analysis revealed robust immune cell infiltration, including increased CD8-positive T cells, CD20-positive B cells, and macrophages, along with newly observed PD-L1 expression, suggesting a strong antitumor immune response.

The therapy protocol included seven MeV IT injections over three weeks, followed by three VSV injections in subsequent weeks. The intensive treatment schedule aimed to maintain high IT virus concentrations. Imaging studies documented transient tumor swelling during therapy, likely due to immune cell infiltration, which is often referred to as pseudo progression, followed by significant tumor softening. Two months post-therapy, the tumor was surgically removed, with no malignant cells detected in the excised tissue. The patient subsequently completed one year of adjuvant trastuzumab therapy due to her HER2 positive status and remains recurrence-free 45 months later.

Nursing Considerations

OVT is an emerging approach in the treatment of various cancers, including aggressive subtypes like TNBC, where traditional therapies often fall short. The principle behind oncolytic viruses involves the use of engineered or naturally occurring viruses that selectively infect and destroy tumor cells. These viruses not only directly kill cancer cells by replicating within them but also stimulate an immune response that targets remaining cancer cells.³

The use of OVT in neoadjuvant treatment of breast cancer is gaining attention. Researchers are exploring how these therapies can be combined with other treatments, such as immune checkpoint inhibitors, to enhance their effectiveness.

As of now, Talimogene laherparepvec (T-VEC), a genetically modified herpes simplex virus (HSV), is the only oncolytic virus therapy approved for clinical use. It is FDA-approved for the treatment of unresectable melanoma. Although T-VEC is not yet approved for use in the neoadjuvant setting, ongoing clinical trials are actively exploring this potential, particularly for breast cancer and other solid tumors.³

The case in this article highlights the potential of OVT as a neoadjuvant treatment for aggressive breast cancers. While the findings are preliminary, they underscore the need for further investigation into the use of OVT to downstage tumors and enhance the efficacy of surgical interventions in cancer treatment.

For patients interested in exploring OVT, oncology nurses play a crucial role in connecting them to appropriate clinical trial opportunities. By staying informed about ongoing research and emerging treatment options, nurses can support patients in accessing cutting-edge therapies and contribute to the advancement of cancer treatment options.

References

1. Forčić D, Mršić K, Perić-Balja M, et al. An Unconventional Case Study of Neoadjuvant Oncolytic Virotherapy for Recurrent Breast Cancer. Vaccines (Basel). 2024;12(9):958. Published 2024 Aug 23. doi:10.3390/vaccines12090958
2. Triple-negative breast cancer. American Cancer Society. March 1, 2023. Accessed December 6, 2024. https://www.cancer.org/cancer/types/breast-cancer/about/types-of-breast-cancer/triple-negative.html.
3. Oncolytic virus therapy. Cancer Research Institute. August 2, 2023. Accessed December 6, 2024. https://www.cancerresearch.org/treatment-types/oncolytic-virus-therapy.