Leiden, The Netherlands, September 27, 2018 – ISA Pharmaceuticals B.V., a clinical-stage immuno-oncology company, today announced the publication of the results of a Phase 2 combination trial with ISA’s synthetic long-peptide (SLP) HPV-16 vaccine ISA101 and nivolumab, a monoclonal antibody and PD-1 checkpoint inhibitor (NCT02426892). The open-label trial in patients with HPV-16 associated cancers demonstrated safety and efficacy, resulting in an improved survival as compared to historical nivolumab monotherapy results. It was conducted by MD Anderson Cancer Center in collaboration with ISA Pharmaceuticals and Bristol-Myers Squibb. The results are published in JAMA Oncology today (doi:10.1001/jamaoncol.2018.4051; https://jamanetwork.com/journals/jamaoncology/article-abstract/2703886)

The trial included 24 patients with incurable HPV16-positive cancers; 22 of whom had oropharyngeal cancer, a subtype of head and neck cancer. All patients had received prior cytoreductive therapy for advanced disease. Patients received ISA101 on days 1, 22 and 50. Nivolumab was administered i.v. every 2 weeks as of day 8 for up to one year. The primary objective was assessment of efficacy defined as overall response rate (ORR) by RECIST v. 1.1. Secondary objectives were assessment of safety, tolerability, HPV-specific immune responses, progression-free survival (PFS), and overall survival (OS). The combination of ISA101 and nivolumab was very well-tolerated. Overall response rate was 33% (8/24); all responses occurred in the patients with oropharyngeal cancer. The one-year and median survival rates are estimated at 70% and 17.5 months, respectively.

“These are promising results when compared to historical data with nivolumab monotherapy in HPV-related oropharynx cancer, albeit this was a small single arm trial with a heterogeneous patient population,” said Bonnie Glisson, MD, Professor at The University of Texas MD Anderson Cancer Center and Principle Investigator of the trial. “These findings support our hypothesis that induction of a heightened HPV-specific immune response with vaccine augments the proportion of patients benefiting from CPB therapy and clearly merit confirmation in a randomized trial.”

“We are very pleased with the results,” said Kees Melief, CSO of ISA Pharmaceuticals, “The data not only add to a growing body of evidence that the future of cancer treatment lies in combination therapy addressing multiple targets and mechanisms, but they also demonstrate that ISA’s SLP vaccines may be an important cornerstone of this approach. In a trial combining ISA101 with standard-of-care chemotherapy in cervical cancer patients it has been shown that this approach leads to a stronger, vaccine-induced HPV16-specific immune response. Moreover, this combination appears to be associated with improved clinical outcome. The latest data suggest that the efficacy of anti-PD-1 therapy can be augmented by vaccination, thereby stimulating a larger repertoire of tumor-specific T cells. As a next step, we will conduct a randomized trial to confirm these findings.”

“The outcome of this trial is an important confirmation of our therapeutic approach,” said Gerben Moolhuizen, CEO of ISA Pharmaceuticals, “We look forward to initiating further clinical trials combining our SLP vaccines with other cancer therapeutics.”

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About ISA Pharmaceuticals

ISA Pharmaceuticals B.V. is an immunotherapy company developing rationally designed, fully synthetic immunotherapeutics against cancer and persistent viral infections. The company has built a proprietary immunotherapy platform based on the Synthetic Long Peptide (SLP^®) concept and AMPLIVANT^® technology. SLP^® immunotherapies are designed to fully harness and direct the body’s own defenses towards fighting the disease. In December 2017, ISA Pharmaceuticals closed a clinical immuno-oncology collaboration with Regeneron to advance its SLP^® lead compound ISA101, an immunotherapy targeting human papillomavirus type 16 (HPV16)-induced cancer, in combination with Cemiplimab (REGN2810), a PD-1 (programmed cell death protein 1) antibody. In addition, ISA develops SLP^® immunotherapies to advance novel treatment options for orphan indications.

For more information, please visit www.isa-pharma.com.

SLP^® and AMPLIVANT^® are registered trademarks in Europe.

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