Human Papillomavirus (HPV) - associated head and neck cancers
Human Papillomavirus, or HPV, is estimated to cause about 5% of the worldwide burden of cancer including approximately 99% of cervical cancers, 25% to 60% of head and neck cancers, 70% of vaginal cancers and 88% of anal cancers. The majority of these cancers are caused by the HPV serotype 16. Most infections with HPV are cleared from the body with no lasting consequences. However, in some cases, HPV DNA becomes integrated into chromosomal DNA. When host cells take up this DNA, they express the HPV E6 and E7 proteins. This can potentially lead to cancer since expression of these proteins leads to alterations in cell cycle control, which in turn predisposes these cells to becoming cancerous.
Our solution: HB-201 and HB-202
Both HB-201 (LCMV) and HB-202 (PICV) are TheraT®-based product candidates expressing a non-oncogenic but highly antigenic E6/E7 fusion protein from HPV16. In animal models, HB-201 was observed to be highly immunogenic, resulting in a robust CD8+ T cell response. Based on the levels of antigen-specific CD8+ T cells induced by HB-201 in preclinical models, notably when compared to the levels induced by other approaches including adoptive cell therapies, as observed in separately designed and conducted third-party clinical trials, we believe that HB-201 monotherapy has the potential to provide therapeutic benefit to patients across the broader HPV16+ cancer setting. We have observed strong immunogenicity and robust anti-tumor activity in mouse models for HB-201 alone as well as for the sequential administration of HB-201 and HB-202.
We initiated a Phase 1/2 clinical trial for HB-201 in patients with treatment-refractory HPV16+ cancers in December 2019 and expect preliminary results in late 2020 or early 2021. Our second planned Phase 1/2 clinical trial will assess the safety and efficacy of the combination of HB‑201 and HB‑202 in HPV16+ cancers, with or without an approved checkpoint inhibitor. The HB-202 IND application was cleared by the FDA in June 2020 and we expect the trial to commence later in 2020.
*ClinicalTrials.gov Identifier: NCT04180215
Prostate Cancer is the most common cancer in American men. In 2018 in the US alone there were 164,000 men diagnosed with prostate cancer. An estimated 1.1 million men worldwide were diagnosed with prostate cancer in 2012, accounting for 15% of all cancers diagnosed in men, with almost 70% of the cases (759,000) occurring in more developed regions. With an estimated 307,000 deaths in 2012, prostate cancer is the fifth leading cause of death from cancer in men (6.6% of the total men deaths). In 2018 in the US alone there were 164,000 men diagnosed with prostate cancer with 30,000 deaths, representing an annual mortality rate close to 10%. Despite significant progress in the treatment of prostate cancer, mainly through the targeting of the androgen pathway, significant work remains. Metastatic hormone resistant prostate cancer (mHRPC) is defined as prostate cancer that has spread from its original location to other parts of the body.
Our solution: HB-301
We are pursuing the development of product candidates based on our arenavirus platform to target self-antigens, non-viral antigenic proteins that are highly overexpressed in solid tumors or only minimally expressed in normal cells. HB-301 is a TheraT®* product candidate in metastatic, hormone-resistant prostate cancer. Prostate cancer provides a unique treatment opportunity for immunotherapy because prostate cancer cells express a number of tumor specific antigens that serve as potential targets. HB-301 targets three of these antigens: prostatic acid phosphatase, or PAP, prostate specific antigen, or PSA, and prostate-specific membrane antigen, or PSMA.