Cell therapy improves function in severe HF patients

Caroline Helwick

April 19, 2011

San Diego, CA - An experimental cardiac repair cell product using autologous expanded bone-marrow cells substantially improved signs and symptoms of severe heart failure in patients, according to results of the IMPACT-DCM phase 2 study, reported at the International Society for Heart & Lung Transplantation 2011 Scientific Sessions[1].

"In the six-month interim results, there were consistent and positive trends in symptoms and functional and structural parameters in the treated ischemic patients as compared with the controls," said Dr Brian A Bruckner (Methodist DeBakey Heart and Vascular Center, Houston, TX).

Autologous expanded bone marrow was used in the trial as the sole therapy for patients with dilated cardiomyopathy (DCM) associated with severe heart failure who had no other treatment options.

The multicenter phase 2 trial enrolled 40 patients with DCM and an LVEF <30% (20 ischemic DCM and 20 nonischemic DCM patients). Patients in each group were randomized 3:1 to the experimental treatment or standard medical therapy (control group).

For the treatment, 50 mL of bone marrow are taken from the patient's hip in a 15-minute outpatient procedure; the aspirate is cultured for 12 days, then the expanded mixed-cell therapy (ixmyelocel-T, Aastrom Biosciences) is returned to the patient via a minithoracotomy procedure, with 25 to 30 injections (75 to 100 million cells) administered into the myocardium. Patients were followed for six to 12 months.

Interim efficacy results (in 58% of patients who completed treatment in the bone-marrow group and 33% of controls) showed substantial improvement after the cell therapy, Bruckner reported. Improvements in quality of life, based on NYHA score, were particularly noticeable in the ischemic DCM patients receiving ixmyelocel-T. Increases in the six-minute-walk distance at one month were observed in eight of 10 ischemic DCM patients treated with ixmyelocel-T and one of 10 nonischemic DCM patients (9/20 total). In the control arm, one-month improvements were noted for one of five ischemic DCM patients and four of seven nonischemic DCM patients (5/12 total). At 12 months, functional improvements were seen in four of six ischemic DCM and six of seven nonischemic DCM patients receiving ixmyelocel-T (10/13) and in zero of two ischemic DCM and three of three nonischemic DCM (3/5 total) patients receiving medical therapy.

Structural assessments showed an increase in septal thickness at six months in seven of 10 ischemic DCM and three of nine nonischemic DCM patients treated with ixmyelocel-T (10/19 total) and in one of three ischemic DCM and four of five nonischemic DCM (5/8 total) controls. There was no statistically significant difference between ixmyelocel-T and control patients in the end points, Bruckner noted.

"Several patients had fairly dramatic results," according to Bruckner. For example, a 74-year-old male with NYHA class 4 heart failure and a starting LVEF of 10% improved, three months postsurgery, to NYHA class 2 with an LVEF of 30%. Another patient improved from NYHA class 3 to NYHA class 1 after six months.

A total of 474 adverse events occurred across the study, most relating to the aspiration and intramyocardial injections. But from day 7 on, adverse events were similar for the ixmyelocel-T and control patients.

Moving forward, the investigators will be assessing a less invasive means of delivering the cells, including by catheter, Bruckner said.

The study was sponsored by Aastrom Biosciences . Bruckner reported no relevant conflicts of interest.


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