Cell Therapeutics, Inc. has reported that enrolment on its pioneer lung cancer clinical trial has been temporarily suspended while the company awaits follow up data of recently enrolled patients.

After consultation with the company and the study's steering committee, the Data Safety Monitoring Board (DSMB) recommended and CTI agreed to suspend enrolment on the trial to allow maturity of the data and assessment of differences in early cycle deaths observed between arms of the study. While most of the deaths were attributed to disease progression, more complete data is required to analyse this difference. Also according to the recommendation of the DSMB, all patients who are currently on the trial will continue to be treated per the protocol.

In addition, as a planned follow up to its May meeting with and following recommendations from the US Food and Drug Administration (FDA), the company reviewed the demographic and estrogens data of the patients on the Pioneer study and plans to amend the current study while enrolment is suspended.

The study will be amended to focus on the primary efficacy endpoint of survival in women with normal estrogens levels; the subset of patients that demonstrated the greatest survival benefit in the stellar trials.

"Meeting with the FDA, we decided to use the initial enrolment in this study to determine whether the proportion of patients who have normal estrogens levels is equivalent to what was expected based on our experience in the stellar trials," said James A Bianco, MD, president and CEO of CTI. "Given that only approximately one-half of patients sampled have normal estrogens levels in the pioneer trial compared to approximately two- thirds of patients for which estrogens data was available in our prior stellar trials, we decided it would be prudent to amend the protocol to focus the primary endpoint analysis on the subgroup of patients in which we saw the greatest survival difference in our stellar trials patients with normal estrogens levels."

The pioneer study was initiated in December 2005 using pre-menopausal age to stratify patients. Based on feedback from the FDA, CTI will utilize the Agency's recommendation to amend the protocol to use estrogens level as a stratification factor and as the primary efficacy endpoint of the study. The company expects to submit an amendment to the FDA under a Special Protocol Assessment request as soon as practicable. The company anticipates the change to the protocol will push the interim analysis of the pioneer trial back by at least six months.