Aduro Biotech's Stock Craters After Pancreatic Cancer Drug Trial Misses Primary Endpoint

Published: May 17, 2016

Aduro Biotech's Stock Craters After Pancreatic Cancer Drug Trial Misses Primary Endpoint May 16, 2016
By Alex Keown, BioSpace.com Breaking News Staff

BERKELEY, Calif. – of Aduro Biotech have fallen more than 25 percent this morning following news that the company’s Phase II trial for its combination pancreatic cancer drug, CRS-207 did not meet its primary endpoint of survivability.

Aduro said its Eclipse trial of CRS-207 failed to show an improvement in overall survival for patients with pancreatic cancer who had failed at least two prior therapies in the metastatic setting. Median overall survival was 3.8 months for patients treated with the immunotherapy regimen of CRS-207 and the cancer vaccine GVAX pancreas, 5.4 months for patients treated with CRS-207 alone and 4.6 months for patients administered chemotherapy. Aduro said there were no reported safety concerns during the trial and full study findings will be presented at a later date.

Stephen T. Isaacs, chairman, president and chief executive officer of Aduro, called the findings a disappointing and “unexpected outcome.’

“While we are well aware of the very difficult-to-treat nature of late-stage metastatic pancreatic cancer, we are surprised by the divergence of these data from the results of our Phase IIa study. At the same time, we continue to look forward to the interim results later this year from our ongoing Stellar trial, which is evaluating CRS-207 and GVAX Pancreas with and without the anti-PD1 checkpoint inhibitor nivolumab as a second-line therapy for patients with metastatic pancreatic cancer,” Isaacs said in a statement.

Each year, it is estimated that more than 337,000 people worldwide are diagnosed with pancreatic cancer and more than 330,000 people die from the disease.

Isaacs said he and the science team at Aduro believe the scientific rationale for combining CRS-207 with a checkpoint inhibitor is compelling. But, he said, after reviewing the overall survivability, the company is “intrigued by activity seen with CRS-207 as a single-agent.”

“While the median duration of 5.4 months appears greater for CRS-207, the overall survival curve of CRS-207 alone was comparable to overall survival seen with chemotherapy. Of note, due to a disproportionately high dropout rate in the single-agent chemotherapy arm, most of these patients instead received a variety of combination treatments, including chemotherapies, immunotherapies and targeted therapies,” said Dirk Brockstedt, executive vice president, research and development at Aduro.

This is not the first time Aduro’s stock has taken a hit due to CRS-207. In November, Aduro stock fell after the company reported a trial patient taking CRS-207 developed a serious infection related to the medication. The company noted that the combination treatment can cause some adverse side effects, including the development of lymphopenia. Some patients in a Phase IIa clinical trial did come down with the illness, but the company also noted one patient developed a more serious infection. Buried on page 31 of a filing to the U.S. Securities and Exchange Commission is a one-paragraph report on the patient being diagnosed with Listeria monocytogenes.

Aduro’s CRS-207 does have developmental competition from Advaxis . However, last summer the U.S. Food and Drug Administration placed a hold on experimental cancer treatment axalimogene filolisbac following the death of a patient. Like Aduro’s combination treatment, Advaxis’ therapy uses listeria to help trigger the body’s immune system to fight the cancerous cells. The Advaxis’ trial patient was hospitalized and treated for Listeria monocytogenes two years after taking axalimogene filolisbac as part of an investigator-initiated trial in 2013.

Although Aduro’s stock is down, Isaacs said Aduro is well positioned “with a strong cash position and three differentiated, potentially synergistic immunotherapy platforms comprising our LADD, STING pathway activator and B-select monoclonal antibody programs.

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