UC team first in world to achieve complete remission of aggressive pituitary tumor through immunotherapy

The research team, represented by UC’s Jonathan Forbes, MD, is now encouraging the worldwide neurosurgical and neuro-oncology communities to use tumor genomic testing in pituitary carcinomas (PCs) and aggressive pituitary adenoma (APAs) to guide consideration for immunotherapy as a potential first-line treatment.

The team’s findings were published on May 1, 2026, in the journal Surgical Neurology International. An additional letter to the editor was published in the Pituitary journal last July advocating for expanded access to immunotherapy for patients with APAs and PCs.

In the case study, Forbes and his colleagues detail a patient who presented with visual loss and was found to have a pituitary tumor. The tumor was completely removed with full restoration of vision after surgery.

Pathological testing found the tumor to be incredibly biologically aggressive. The patient received post-operative radiation therapy and remained tumor-free for about a year following surgery.

When the tumor came back, the patient was started on first-line temozolomide, which failed to suppress tumor growth. After additional tumor growth, resulting in multi-focal progressive and double vision, the patient considered hospice before electing to proceed with a clinical trial. 

The team at the UC Brain Tumor Center used tumor genomics, which identified a specific mutation in mismatch repair, to identify a clinical trial felt to be an optimal fit for the patient.

“Following a thorough review of tumor genomics, we were able to get the patient signed up for the right clinical trial,” Forbes said. “Using that scientifically-informed regimen, he was able to clear the cancer. The double vision completely resolved on the immunotherapy regimen. It was the first in the world to have a complete response, meaning the cancer completely vanished and did not return after the medication was stopped.”

Since the team published an initial case report, three additional patients from around the world with aggressive pituitary tumors or pituitary carcinomas have been confirmed to achieve complete response after treatment with immunotherapy. Forbes said it should become standard practice to test the DNA of each pituitary tumor and offer immunotherapy for patients with certain mutations.

“In this manuscript, we have outlined that these types of tumors have certain mutations of DNA, including mutations in mismatch repair. Providers across the country and the world need to know to look for the mutations,” Forbes said. “If the tumor DNA fits a particular profile, patients should be permitted to have expanded access to these potentially life-saving medications immediately.”

Moving forward, the team plans to evaluate the same regimen of testing tumors and providing immunotherapy to treat glioblastomas, one of the most aggressive and deadly brain tumors. A planned Phase 1 trial will utilize navigated focused ultrasound technology to aid the immunotherapy in crossing the blood-brain barrier and reaching the tumor in order to activate the immune system to kill the cancer.

“This case report reinforces that there are major discoveries happening here at our Cancer Center in Cincinnati,” Forbes said. “It is incredibly important for patients in our region to have unencumbered access to innovative and scientifically informed clinical trials. We have the infrastructure and expertise to find answers to these questions.”

Featured photo at top of a CT brain scan. Photo/Tonpor Kasa/iStock.