FDA Approves Imfinzi Therapy in Muscle Invasive Bladder Cancer

The U.S. Food and Drug Administration has approved neoadjuvant treatment with the immunotherapy agent Imfinzi (durvalumab) plus gemcitabine and cisplatin, followed by single-agent, adjuvant Imfinzi following radical cystectomy in adult patients with muscle invasive bladder cancer, the regulatory agency announced.

The efficacy of neoadjuvant Imfinzi was evaluated in the phase 3 NIAGARA trial, a randomized, open-label, multicenter investigation which enrolled 1,063 patients who were candidates for radical cystectomy (surgery to remove the urinary bladder) and had not yet received prior systemic therapy for their cancer. The trial randomized patients to receive either neoadjuvant Imfinzi with chemotherapy followed by adjuvant Imfinzi after surgery or neoadjuvant chemotherapy followed by surgery alone.

During a pre-specified interim analysis of NIAGARA, the investigative combination demonstrated a statistically significant improvement in event-free survival and overall survival. The event-free survival was not reached in the Imfinzi and chemotherapy treatment arm whereas it was 46.1 months in the chemotherapy alone arm. Looking to median overall survival, it was not reached in the investigative combination arm and was also not reached in the chemotherapy alone arm.

Notably, according to the FDA’s website, fda.gov, side effects experienced on the trial were consistent with that of prior Imfinzi and platinum-based chemotherapy experience.

For patients weighing at least 30 kilograms, according to the regulatory agency, the recommended dose of Imfinzi is 1,500 milligram every three weeks in combination with chemotherapy prior surgery. After surgery, patients are to continue receiving 1,500 milligrams of Imfinzi alone every four weeks. For those weighing less than 30 kilograms, the dose is based on body weight.

Treatment should continue until one of the following occurs: the disease progresses to a point where surgery is no longer an option, the cancer returns, side effects become too severe or the patient completes a maximum of eight cycles after surgery.

Regarding primary end points, event-free survival served as the major efficacy outcome, which was evaluated by blinded independent central review, though overall survival was an additional efficacy outcome.

What is Neoadjuvant and Adjuvant Treatment?

Neoadjuvant and adjuvant therapy administration, according to the Rocky Mountain Cancer Centers, is used alongside surgery to treat cancer. Neoadjuvant treatment is delivered prior to a surgery, like cystectomy, and aims to shrink a tumor or stop the spread of the cancer; this is done in order to make surgery less invasive and more effective. Contrarily, adjuvant therapy is utilized directly after surgery and is done so to kill off any remaining cancer cells; the goal is to reduce the chances of recurrence.

The NIAGARA study utilized the idea of both neoadjuvant and adjuvant treatment to increase the likelihood of patients surviving without progression.

“So, what's the NIAGARA study? The NIAGARA study evaluated patients in which we want to get a high cure rate. Previously, for patients that had cystectomy, the standard of care was chemotherapy, surgery and then afterwards was to watch followed by consideration of immunotherapy, but there was no overall survival,” Dr. Chandler Park explained in an exclusive interview with CURE on the topic of the study.

“Based on the [trial] update, if a patient received chemotherapy with [Imfinzi] immunotherapy, they had a much higher chance, that after surgery, they would remain cured,” he continued. “Everybody today that has stage 2 bladder cancer and received treatment before the surgery should ask their medical oncologist for chemotherapy and an immunotherapy. Then, after surgery, maybe even consider immunotherapy afterwards. That's something I would encourage.”

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