Bcl-XL_42-CAF09b Vaccination for Patients With Prostate Cancer With Lymph Node Metastases

In this Phase I study, patients with hormone-sensitive Prostate Cancer (PC) and lymph node metastases are treated with the cancer vaccine Bcl-xl\_42-CAF09b. The aim of the study is to clarify the safety and toxicity of the vaccine and also the immunological effect. The vaccine Bcl-xl\_42-CAF09b is composed of the peptide Bcl-xl\_42 and the adjuvant CAF09b. The B-cell lymphoma extra large protein (Bcl-xl) protein plays a vital role in the cancer cell's ability to avoid programmed cell death (apoptosis) and is upregulated in a variety of cancerous diseases. Bcl-xl\_42 is a peptide fragment of the full protein and preclinical studies have shown that vaccination with this peptide (Bcl-xl) can activate the immune system and thereby lead to the death of cancer cells. In order to improve the activation of the immune system, adjuvant CAF09b is added; Preclinical studies have shown that special intraperitoneal (IP) injections of CAF09b improve the activation of the immune system.

Background: In this Phase I study, patients with hormone-sensitive Prostate Cancer (PC) and lymph node metastases are treated with the cancer vaccine Bcl-xl\_42-CAF09b. The aim of the study is to clarify the safety and toxicity of the vaccine and also the immunological effect. Patients included should be on Bicalutamid treatment upon inclusion. The vaccine Bcl-xl\_42-CAF09b is composed of the peptide Bcl-xl\_42 and the adjuvant CAF09b. The B-cell lymphoma extra large protein (Bcl-xl) protein plays a vital role in the cancer cell's ability to avoid programmed cell death (apoptosis) and is upregulated in a variety of cancerous diseases. Bcl-xl\_42 is a peptide fragment of the full protein and preclinical studies have shown that vaccination with this peptide (Bcl-xl) can activate the immune system and thereby lead to the death of cancer cells. In order to improve the activation of the immune system, adjuvant CAF09b is added; Preclinical studies have shown that special intraperitoneal (IP) injections of CAF09b improve the activation of the immune system. The CAF09 adjuvant has been developed by Statens Serum Institut (SSI). It is a three-component adjuvant system, composed of cationic liposomes (DDA-MMG1) with complex bound synthetic double-stranded RNA (Poly(I:C)2). The adjuvant was developed as a means to induce cytotoxic CD8+ T-cell responses against vaccine antigens and intended for use in vaccines against disease targets such as cancers, human immunodeficiency virus or Hepatitis C virus. The Poly(I:C) component has previously been in clinical studies as a cancer treatment. Poly(I:C) is known for its pyrogenic activity but upon formulation in the cationic liposome system, CAF09, the pyrogenic effect is significantly reduced. Methods: 20 patients will be included in this phase I trial. 10 patients will be included in arm A and 10 patients in arm B. Arm a will recieve 3 vaccines every second week IM and thereafter 3 vaccines every second week IP. Arm B will first receive 3 vaccines every second week IP and thereafter every second week IM. All 20 patients will recieve 6 vaccines all in all. This is not randomized - the first 10 patients included will be in arm A and the last 10 patients included will be in arm B. Patients will be followed with clinical controls every second week.