Xcyte Gives Mixed Picture at ASCO

[Guest guest]

[The good news: Xcellerated T cells shrink lymph nodes, spleen.

Platelets and neutrophil counts went up.

The bad news: Lymphocyte counts unchanged.

Will this therapy be better in combination with other drugs?]

June 07, 2004 01:00 PM US Eastern Timezone

Xcyte Therapies, Inc., Presents Results of Clinical Trials in Chronic

Lymphocytic Leukemia, Multiple Myeloma, and Prostate Cancer at

American Society of Clinical Oncology Meeting

BIOWIRE2K

American Society of Clinical Oncology Meeting

SEATTLE--(BUSINESS WIRE)--June 7, 2004--Xcyte Therapies, Inc.

(Nasdaq:XCYT) announced that clinical results from three Phase I/II

company-sponsored trials of Xcellerated T Cells in patients with

chronic lymphocytic leukemia (CLL), multiple myeloma, and prostate

cancer were presented today at the American Society of Clinical

Oncology (ASCO) meeting in New Orleans.

In the CLL trial, 17 patients received a single infusion of

Xcellerated T Cells without other treatment for their leukemia.

In CLL, leukemic cells infiltrate the lymph nodes, spleen and blood,

leading to enlargement of the lymph nodes and spleen and increased

leukemia cell counts in the blood.

At the time of the ASCO presentation, 14 patients were evaluable, 11

(79%) of whom demonstrated a more than 50% reduction in the size of

their enlarged lymph nodes. Ten (83%) of the 12 patients with

enlarged spleens demonstrated a more than 50% reduction in spleen

size as determined by physical examination. These effects were

maintained for the twelve week observation period of the trial.

Decreases in leukemic cell counts in the blood were not observed.

Sustained increases in T lymphocytes as well as in neutrophil and

platelet counts were seen, suggesting that Xcellerated T Cells may

also have positive effects on elements of the hematological system.

Resolution of symptoms related to leukemia was observed in 7 (78%) of

the 9 symptomatic patients. Observed side effects thought to be

related to the therapy were low-grade, and included fever and

headache associated with the infusion.

" The combination of reductions in size of the lymph nodes and

spleens, which are enlarged from leukemic infiltration, with the

resolution of disease-related symptoms, provides evidence of the

potential activity of Xcellerated T Cells in CLL, " said Dr.

G. Wierda, Assistant Professor of Medicine at The University of Texas

M.D. Cancer Center, who presented the study. " These effects

were achieved with minimal toxicity associated with the treatment in

this study. "

" Based on these promising results, we have amended the protocol for

this study to allow patients to be retreated with Xcellerated T

Cells, " said Mark Frohlich, M.D., Medical Director and Vice President

of Xcyte Therapies. " In addition, we plan to initiate a clinical

trial in which patients with CLL will be treated with Xcellerated T

Cells after treatment with Campath® (alemtuzumab). "

In the multiple myeloma trial, 36 patients were treated with

Xcellerated T Cells three days following high dose chemotherapy and

peripheral blood stem cell transplantation. A reduction of at least

90% in the M-protein, a standard marker used to measure the amount of

disease in patients with multiple myeloma, was seen in 51% of the

patients in this trial. In addition, lymphocytes and T cells reached

normal levels within a few days following infusion of Xcellerated T

Cells. In contrast, it typically takes several weeks for these cells

to reach normal levels after a standard peripheral blood stem cell

transplant. The T cell repertoire, a measure of the ability of T

cells to react with a broad variety of targets, was also normalized

at one month following transplant in 4 of the 5 patients in whom it

was measured, in contrast to the markedly abnormal repertoire

typically seen for a year or more in patients with multiple myeloma

following autologous stem cell transplantation.

" This clinical trial provides the first demonstration that lymphocyte

and T cell recovery can be favorably affected following peripheral

blood stem cell transplantation, " said Dr. I.M. Borrello, Assistant

Professor in Oncology at the s Hopkins Oncology Center, who

presented the study. " The rapid return of a normal T cell repertoire

in these patients was also noteworthy, and may lead to improved

responses to infectious agents, vaccines and the patient's cancer. "

In the prostate cancer trial, 19 patients with hormone-refractory

prostate cancer received a single infusion of Xcellerated T Cells

without other anti-tumor therapy. Sustained increases in lymphocyte

and neutrophil counts were observed over the four month observation

period of this clinical trial. In addition, two of the 19 patients

had a greater than 50% reduction in prostate specific antigen, a

serum marker of prostate cancer.

" Safety was the primary endpoint in all three of these clinical

trials, " noted Ron Berenson, M.D., President and Chief Executive

Officer of Xcyte Therapies. " Patients generally experienced mild side

effects, such as fever, headaches and nausea, which resolved shortly

after the infusion of Xcellerated T Cells. No dose limiting

toxicities were identified in these studies. Anti-tumor effects and

sustained increases in lymphocyte counts were observed in all of the

clinical trials. Interestingly, we also saw increases in neutrophil

and platelet counts, possibly as a result of the infused T cells.

Together, these findings provide a strong rationale for our ongoing

clinical program. We have initiated Phase II trials in patients with

relapsed or refractory multiple myeloma and in patients with indolent

forms of non-Hodgkin's lymphoma. "

Xcyte Therapies is developing novel therapies that harness the power

of the immune system to treat cancer and other serious illnesses.

Xcyte derives its therapeutic products from a patient's own T cells,

which are cells of the immune system that orchestrate immune

responses and can detect and eliminate cancer cells and infected

cells in the body. Xcyte uses its patented and proprietary Xcellerate

Technology to generate activated T cells, called Xcellerated T Cells,

from blood that is collected from the patient. Activated T cells are

T cells that have been stimulated to carry out immune functions. The

Xcellerate Technology is designed to rapidly activate and expand the

number of the patient's T cells outside of the body. These

Xcellerated T Cells are then administered to the patient.

Xcyte, Xcyte Therapies, Xcellerate and Xcellerated T Cells

are trademarks of Xcyte Therapies, Inc. Campath® is a

registered trademark of ILEX Oncology, Inc.