BERKELEY, Calif.--(BUSINESS WIRE)--Aduro BioTech, Inc., a leader in cancer immunotherapy, today announced the presentation of updated safety and efficacy data from an ongoing Phase 1b clinical trial of its novel immunotherapy CRS-207 in combination with standard chemotherapy in patients with unresectable malignant pleural mesothelioma (MPM). Of 16 evaluable patients with response data, 75% (12/16) had confirmed durable partial responses (PR) and 19% (3/16) experienced stable disease (SD) after CRS-207 and chemotherapy, for a 94% rate of disease control (PR and SD). At the time of the presentation, estimated progression-free survival was 7.5 months with one patient on study for more than 19 months, currently receiving maintenance therapy with CRS-207 following the combination treatment.
The results were presented by Raffit Hassan, M.D., winner of the 2014 Wagner Medal for his career work in mesothelioma and co-chief of the Thoracic and GI Oncology Branch at the National Cancer Institute, in an oral presentation at the International Mesothelioma Interest Group (iMig) Conference held in Cape Town, South Africa. CRS-207, based on Aduro’s live-attenuated, double-deleted (LADD) Listeria monocytogenes immunotherapy platform, has been engineered to induce a potent innate immune response as well as an adaptive immune response targeting mesothelin, an antigen over-expressed in MPM tumors.
“We continue to be excited by the results from this trial of our novel immunotherapy in combination with chemotherapy in this difficult-to-treat patient population,” said Stephen T. Isaacs, chairman, president and chief executive officer of Aduro. “While the findings warrant further investigation, we believe CRS-207 may prove to be a very attractive therapeutic option in the armamentarium to improve overall response rates and boost the duration of those responses.”
Dirk G. Brockstedt, Ph.D., senior vice president of research and development at Aduro, added, “These results continue to support the promise of our technology as a method to boost and rally a patient’s immune system to target tumors. We plan to further evaluate CRS-207 in combination with chemotherapy in a randomized, controlled Phase 2 clinical trial in mesothelioma, which we anticipate to begin in the first half of 2015.”
The multi-center Phase 1b study is open to patients with unresectable MPM who are chemotherapy-naïve, have good performance status (ECOG 0 or 1) and adequate organ function. Under the trial design, eligible patients receive two prime vaccinations with CRS-207 two weeks apart, followed by up to six cycles of standard of care pemetrexed and cisplatin chemotherapy three weeks apart and then two CRS-207 boost vaccinations three weeks apart. Clinically stable patients are eligible to receive CRS-207 maintenance vaccinations every eight weeks. Subjects are followed every eight weeks until disease progression. Objectives of the study are to assess safety, immunogenicity, objective tumor responses and tumor marker kinetics. Twenty-three patients have been enrolled thus far and additional response, follow-up and immune response data are pending.
At the time of the presentation, the median time on study was 229 days (range: 155-570 days). No treatment-related serious adverse events or unexpected toxicities were observed. The most common adverse events associated with CRS-207 were infusion-related chills and fever, which were transient, mild and self-limiting.
About Malignant Pleural Mesothelioma
Mesothelioma is a form of cancer that affects the smooth layer of mesothelial cells that surround the chest, lungs, heart and abdomen. Malignant pleural mesothelioma (MPM), which affects the thin balloon-shaped lining of the lungs, is the most common form of this disease and accounts for around 2,500 cases a year in the United States. MPM is an aggressive disease with a poor prognosis. Most MPM patients are not candidates for surgical resection. Based on prior studies, expected median progression-free survival is 5.7 months and overall survival is 12.1 months with combination pemetrexed and cisplatin chemotherapy. The tumor-associated antigen mesothelin is overexpressed in virtually all cases of mesothelioma.
CRS-207 is one of a family of product candidates based on Aduro’s live-attenuated, double-deleted (LADD) Listeria monocytogenes immunotherapy platform that induce a potent innate and T cell-mediated immune response. CRS-207 has been engineered to express the tumor-associated antigen mesothelin, which is over-expressed in many cancers including mesothelioma and pancreatic, non-small cell lung, ovarian and gastric cancers.
About Aduro BioTech, Inc.
Aduro BioTech, Inc. is a private, clinical-stage biotechnology company focused on immunotherapy for cancer. Aduro’s novel immunotherapy combination in pancreatic cancer has received Breakthrough Therapy Designation from the FDA and is under investigation in the ongoing ECLIPSE Phase 2B clinical trial. Aduro has additional ongoing clinical trials with its LADD platform in mesothelioma and glioblastoma. The company is also developing clinical candidates using novel small molecules that activate the intracellular STING receptor, a central mediator of the innate immune response. For more information, please visit www.aduro.com.