Virologist Dr. Beata Halassy from the University of Zagreb injected viruses grown in the lab into the tumor to treat her breast cancer. Four years on from a course of injections, Halassy is still cancer-free, and her case has laid open the scientific community to debate over whether self-experimentation in such cases should be considered ethically justifiable to have value.

Halassy was diagnosed with a recurrent stage 3 tumor in 2020 at the site of a previous mastectomy. With chemotherapy turning out to be futile but also grueling, she went in for an alternative therapy: oncolytic virotherapy (OVT). The virologist did not know much about OVT; still, she had tremendous lab experience, which made her go ahead with the treatment. It took a brave editor to publish the report,” Halassy noted.

How does Oncolytic virotherapy work?

Oncolytic virotherapy, or OVT, is an emerging field of cancer therapy in which viruses selectively infect and lyse cancer cells and stimulate an immune response. To date, only one OVT has received FDA approval in the USA, to treat metastatic melanoma; to date, no OVT is approved for breast cancer treatment.

For her treatment, Halassy administered a cocktail of two viruses: first the measles virus, and then the vesicular stomatitis virus (VSV). Both are viruses she worked with before, and both have excellent safety records. The measles strain she selects is one widely used in vaccines given to children, and the VSV strain induces only mild, flu-like symptoms.

Under the guidance of her oncologists, Halassy continued to do her treatment program for two months; she directly injected research-grade material prepared by herself. The tumor responded positively: it softened, shrunk, and released from the pectoral muscle and skin and could be surgically removed.

Analysis following the tumor's surgical removal revealed that high levels of lymphocytes-immune cells were found infiltrating the tumor, which meant that the viral injections had catalyzed Halassy's immune reaction to attack cancerous cells as well as the virus.s. “An immune response was, for sure, elicited,” she said. Following surgery, she underwent a year of trastuzumab, one of the more potent anticancer drugs, to ensure the remission to be permanent.

Ethics of self-experimentation: A gray area

Though successful, Halassy's self-treatment raised ethical concerns. Many journals refused to publish her paper because they feared that publication could provoke other patients to attempt unproven treatments.“The major concern was always ethical issues,” admits Halassy, but she pursued publishing her findings after experiencing literature supporting the value of self-experimentation.

Jacob Sherkow, an attorney and physician law expert at the University of Illinois Urbana-Champaign, said that the case falls “within the line of being ethical,” but questioned whether her report might incite susceptible cancer patients to seek out unproven remedies. Sherkow also said that knowledge retained from such cases is also of great worth. “I think it ultimately does fall within the line of being ethical, but it isn’t a slam-dunk case,” he said, adding that a commentary on the ethics of self-experimentation could have provided helpful context in the report.

Scientific community's criticism

While supportive of Halassy's findings, several experts are more conservative in deeming her technique revolutionary. Stephen Russell, an OVT expert, said regarding her successful viral injections that this is an important proof-of-principle study, not for earlier-stage cancers. "Really, the novelty here is, she did it to herself with a virus that she grew in her own lab.".

It again brought to the fore that self-experimentation, although carrying incredible potential, still raises serious ethical questions in medical research. Even when she successfully emerges from treatment, the inspirational effect she has on more research into OVT is weighed in scientific and medical opinion by the dangers of encouraging alternative methods for cancer treatment.