Dendreon touts T-cell response data for prostate cancer vaccine Provenge

Dendreon has had no shortage of challenges with Provenge since winning FDA approval for the groundbreaking prostate cancer vaccine back in 2010. Years later, the company has unveiled new data showing the med generates a killer T-cell response—and the strength of that response correlates with overall survival.

In a Monday poster session at the American Society of Clinical Oncology’s annual meeting, Dendreon showcased the new data showing that Provenge elicits a T-cell response to the immunizing antigen A2024 and to the target antigen prostatic acid phosphatase on prostate tumor cells.

The responses were seen as early as six weeks after patients received Provenge and lasted for a minimum of six months, according to the company. Men with both hormone-sensitive prostate cancer and those with metastatic castrate-resistant prostate cancer (mCRPC) experienced the responses, which correlated with improved overall survival, Dendreon reported.

Speaking with FiercePharma, Dendreon president Jim Caggiano said the company will use the findings to educate physicians and will share them with any skeptics who aren’t yet convinced of Provenge’s ability to help patients.

The company has been able to "turn the tide" and increase the number of men receiving Provenge in recent years, Caggiano said, with that trend continuing into this year.

"As we continue to publish data like this, it helps answer any parts of the question that still remain," he said.

The results come shortly after Dendreon released real-world findings from a registry dubbed Proceed that showed a significant survival advantage for African-American Provenge patients.

African-American Provenge patients lived a median 37.3 months after treatment, compared with 28 months after treatment for Caucasian patients, the company reported. Proceed included data on 1,900 patients with mCRPC who received Provenge between 2011 and 2013.

At the time, Caggiano stressed that the data demonstrated Provenge is important for all eligible patients because they "underscore the survival impact of Provenge regardless of race."

Dendreon has had its share of challenges since bringing Provenge to the U.S. market in 2010. The vaccine was once predicted to grow into a blockbuster, but before winning approval it ran into an FDA delay. When Provenge eventually hit the market, numerous operational issues hampered the company until Dendreon declared bankruptcy in 2014.

Valeant Pharmaceuticals bought Dendreon out of bankruptcy in 2015 for $495 million. Facing no share of challenges itself, Valeant offloaded Dendreon to China’s Sanpower last year for $820 million.

Separately on Monday, NewLink Genetics reported that its IDO pathway inhibitor indoximod, administered after the final Provenge infusion in patients with mCRPC, demonstrated a statistically significant increase in radiographic progression-free survival versus placebo in a phase 2 trial.