Abstract
BACKGROUND:
The primary objective of this phase 2 study was to assess the objective response rate (complete response [CR] + partial responses [PR]), by Response Evaluation Criteria in Solid Tumors, of PFβ3512676, a CpG oligodeoxynucleotide, alone in 2 doses or in combination with dacarbazine (DTIC) in patients with unresectable stage IIIB/C or stage IV malignant melanoma, with the aim of selecting an arm to take forward to a phase 3 portion of the study.
METHODS:
A total of 184 patients were randomized to 1 of 4 treatments: PFβ3512676 10 mg (low dose), at 40 mg (high dose), 40 mg plus DTIC (850 mg/m^2^), or DTIC (850 mg/m^2^) alone. Patients received PFβ3512676 subcutaneously weekly in a 3βweek cycle and received DTIC intravenously on the first week of the cycle.
RESULTS:
The objective response rate (PR or CR, confirmed or unconfirmed) in the 40 mg + DTIC arm was 16% (7 patients) compared with 8% (3 patients) with DTIC alone. One (2%) patient in the 10βmg and 0 patients in the 40βmg arms achieved an objective response. Best response of CR or PR or stable disease (SD), with no minimum duration defined for SD, was achieved by 15 (33%) patients in the 40 mg + DTIC arm, 15 (38%) patients in the DTICβonly arm, 8 (17%) patients in the 10βmg arm, and 9 (20%) patients in the 40βmg arm. The most frequently reported adverse events were classified as local injection site reactions or systemic fluβlike symptoms, specifically fatigue, rigors, and pyrexia.
CONCLUSIONS:
PFβ3512676 at the doses used was generally well tolerated. The modest objective response rates observed in all arms did not warrant continuation to the phase 3 portion of the study. Cancer 2009. Β© 2009 American Cancer Society.