Purging of cells using viruses

Abstract

The subject invention relates to viruses that are able to purge (reduce or eliminate) undesirable cells in a mixture of cells. Undesirable cells can include neoplastic cells, cells mediating graft-versus host diseases, and autoimmune cells. The subject invention also relates to the purging of undesirable cells from bone marrow or peripheral blood cell harvests in the treatment of mammals including cancer patients, transplant recipients, and patients with autoimmune disease.

Description

[0001] The subject invention relates to viruses that are able to purge (reduce or eliminate) undesirable cells in a mixture of cells. Undesirable cells can include neoplastic cells, cells mediating graft-versus host diseases, and autoimmune cells. The subject invention also relates to the purging of undesirable cells from bone marrow or peripheral blood cell harvests in the treatment of mammals including cancer patients, transplant recipients, and patients with autoimmune disease.[0002] Ex vivo purging techniques have shown limited success for autologous bone marrow or stem cell transplantation in patients with leukemia or other malignancies. One goal of purging bone marrow or peripheral blood progenitor cells (PBPC) is to remove neoplastic cells while having little effect on normal stem cells and hematopoeitic progenitor cells. Transplantation of the purged marrow occurs after myeloablative therapy such as high dose chemotherapy or radiation [see for example, Stuart R. K., 1993, Se...

AI Technical Summary

Benefits of technology

[0012] It is a further object of the invention to provide a method of preventing graft-versus-host diseases by in a mammal by contacting harvested cells with a virus and transplanting such purged hematopoietic cells into the mammal after myeloablative treatment.

[0045] In another embodiment of the invention, the virus is genetically modified, as for example, to increase its selectivity for neoplastic cells. Methods of genetic manipulation of rhabdoviruses such as VSV are well established (Roberts A., and J. K. Rose, Virology, 1998, 247:1-6) making it possible to alter the genetic properties of the virus.

[0047] An advantageous embodiment of the invention relates a kit for use in the ex vivo purging of undesirable cells from a mixture of desirable and undesirable cells. The kit includes premeasured amounts of formulated virus, or viruses, appropriate to treat a mixture containing a certain number of desirable and undesirable cells. Advantageous formulations include excipients that stabilize the virus against loss of infectivity, or boost the viability or survival of the desirable cells. A more advantageous kit allows for the contacting of the virus formulation with the target mixture of cells to occur in an aseptic step without the need for biocontainment equipment. An example of such a device is a compartmentalized collection container for the target mixture of cells that contains the pre-measured virus in a separate compartment. Creation of a patent pathway between the compartments allows contact between the virus, the target cell population, and one or more excipients. Contact with the virus and excipients, if separate, can occur simultaneously, or sequentially. A further advantageous embodiment of the invention is a type of compartmentalized container that maintains the optimum temperature for virus cell interaction during the time of contact between the virus, or viruses, and the target mixture of desirable and undesirable cells. Another advantageous embodiment of the invention relates to a kit that allows for the separation of the contacted mixture of cells from the virus, excipients, or both after an appropriate amount of time. The appropriate amount of contact time would be known or determined by someone skilled in the art.

[0050] In another advantageous embodiment of the invention, the virus is used to contact the mixture of neoplastic cells and normal cells which are treated before, during or after contact with interferon. Interferon allows for enhanced protection of normal cells (see Example 3 and see Roberts et al., WO / 9918799). The interferon (IFN) is selected from the group-class I (alpha, beta and omega) and class II (gamma), and recombinant versions and analogs thereof as discussed in, for example, Sreevalsoun, T., 1995 (In: Biologic Therapy of Cancer, second edition, edited by V. T. DeVita, Jr., et al., J.B. Lippincott Company, Philadelphia, pp347-364).

Problems solved by technology

Ex vivo purging techniques have shown limited success for autologous bone marrow or stem cell transplantation in patients with leukemia or other malignancies.

However, recent experiments demonstrated that viable cancer cells remained in the bone marrow or PBPC after therapeutic purging leading to relapse of the malignancy.

Another major limitation of current methods of ex vivo purging is the delayed engraftment due to damage to normal stem cells and / or early hematopoietic progenitor cells (Rummel S A and Van Zant G, 1994, J. Hematother. 3:213-218, Damon et al., 1996, Bone Marrow Transplant, 17:93-99).

The resultant loss of early progenitor cells causes a prolonged neutropenia and / or thrombocytopenia which places the patient at increased risk for life-threatening infection and / or bleeding.