Attached files

file filename
EXCEL - IDEA: XBRL DOCUMENT - CTI BIOPHARMA CORPFinancial_Report.xls
10-Q - FORM 10-Q - CTI BIOPHARMA CORPd357343d10q.htm
EX-32 - SECTION 906 CEO AND CFO CERTIFICATION - CTI BIOPHARMA CORPd357343dex32.htm
EX-31.1 - SECTION 302 CEO CERTIFICATION - CTI BIOPHARMA CORPd357343dex311.htm
EX-10.7 - LETTER OF GUARANTEE BETWEEN REGISTRANT AND QUINTILES COMMERICAL EUROPE LIMITED - CTI BIOPHARMA CORPd357343dex107.htm
EX-10.5 - DIRECTOR COMPENSATION POLICY - CTI BIOPHARMA CORPd357343dex105.htm
EX-10.6 - MASTER SERVICES AGREEMENT DATED JULY 9, 2012 - CTI BIOPHARMA CORPd357343dex106.htm
EX-31.2 - SECTION 302 CFO CERTIFICATION - CTI BIOPHARMA CORPd357343dex312.htm

Exhibit No. 15

August 2, 2012

Securities and Exchange Commission

100 F Street, N.E.

Washington, D.C. 20549

Commissioners:

We are aware that our report dated August 2, 2012 on our review of interim financial information of Cell Therapeutics, Inc. for the six month period ended June 30, 2012 included in the Company’s quarterly report on Form 10-Q for the quarter ended June 30, 2012 is incorporated by reference in the Registration Statements of Cell Therapeutics, Inc. on Forms S-3 (File Nos. 333-130411, 333-131533, 333-130004, 333-36038, 333-41300, 333-67906, 333-36603, 333-38431, 333-108926, 333-112681, 333-138170, 333-134126, 333-143452, 333-149980, 333-149981, 333-149982, 333-152171, 333-160969, 333-158272, 333-157376, 333-153358, 333-163479, 333-161442, 333-93835, 333-33872, 333-33268, 333-39385, 333-177506 and 333-182330) and on Form S-8 (File No. 333-65200, 333-58957, 333-35919, 333-97015, 333-106568, 333-106571, 333-112791, 333-118016, 333-146624, 333-152168, 333-158260, 333-162955, 333-170044 and 333-178158).

Yours very truly,

/s/ Marcum LLP

San Francisco, California