Allos Therapeutics, Inc. (NASDAQ: ALTH) today reported updated results from the Company's Phase 1 dose-finding study of FOLOTYN® (pralatrexate injection) which supports the selection of 15 mg/m2 weekly for three weeks out of a four-week cycle as the optimal starting dose and schedule for further evaluation in patients with relapsed or refractory cutaneous T-cell lymphoma (CTCL). Data were presented at the 52nd American Society of Hematology (ASH) Annual Meeting in Orlando, Florida.
“The overall activity in this trial, including the high response rates, durability of response, and favorable safety profile is quite promising. These results suggest that pralatrexate at this dose and schedule may be another important option for treating CTCL.”
"We are continually seeking active and safe systemic therapies to improve the outcomes for our patients with CTCL," said Steven Horwitz, M.D., assistant attending medical oncologist, Memorial Sloan-Kettering Cancer Center, who is serving as the study chair. "The overall activity in this trial, including the high response rates, durability of response, and favorable safety profile is quite promising. These results suggest that pralatrexate at this dose and schedule may be another important option for treating CTCL."
CTCL is a group of T-cell non-Hodgkin lymphomas. In its early stages, CTCL primarily affects the skin, causing patches, plaques, and tumors, as well as redness and itching; however, as it progresses, CTCL can spread to the blood, lymph nodes, and internal organs. For some patients, their disease will progress despite treatment with topical and skin directed therapies and will require systemic treatments, including chemotherapies. Even when CTCL is found in an early stage, it can be difficult to treat and usually returns after initial treatment.
This open-label, multi-center, dose-finding Phase 1 study enrolled 54 patients with relapsed or refractory CTCL who received at least one prior systemic therapy. The first phase of the study employed a dose de-escalating strategy to determine an active, well-tolerated dose and schedule of FOLOTYN in this population. Once the optimal starting dose and schedule was determined to be 15 mg/m2 weekly for three weeks out of a four-week cycle, this cohort was expanded to include a total of 29 patients. The Company had previously announced interim results from this study.
At ASH 2010, data were presented on the 29 patients treated at the optimal starting dose and schedule. Results showed:
- Overall response rate - the percentage of patients whose cancer or tumor was reduced or disappeared after treatment with FOLOTYN - was 45 percent (13 out of 29 patients).
- At the optimal dose, responses were durable - with a Kaplan-Meier estimate for duration of response of 73 percent at six months.
- Median progression-free survival had not been reached at the time of this analysis. At the optimal dose, progression-free survival ranged from 1-429 days.
Of the total 54 patients enrolled in the trial (which includes patients who received lower than the optimal dose), objective responses were observed in 22 patients (41%), including three complete responses (CR) and 19 partial responses. In total, 41 of the 54 patients were treated at the optimal dose of FOLOTYN or higher; of these 41 patients, responses were observed in 21 patients (51%). Responses to FOLOTYN were observed in patients whose disease failed to respond to key prior systemic therapies, including 46 percent of patients whose disease failed to respond to oral bexarotene, 46 percent whose disease failed to respond to methotrexate, 41 percent whose disease failed to respond to HDAC inhibitors, and 36 percent whose disease failed to respond to interferon. Patients in the study were heavily pretreated, having received a median of 6.5 prior therapies (range 1-25) and 4.0 prior systemic therapies (range 1-11).
All 41 patients treated at the optimal dose or higher were evaluable for safety; of these patients, Grade 3-4 adverse events observed were mucositis (17%), thrombocytopenia (3%), and fatigue (3%); the most common Grade 1-2 adverse events observed were fatigue (34%), mucositis (31%), nausea (31%), epistaxis/nose bleeds (24%), edema (14%), and vomiting (14%). There was no neutropenia reported in patients at the optimal dose or higher.
"Allos is pleased with the results observed in this early study which demonstrated the activity of FOLOTYN in heavily pretreated patients with relapsed or refractory cutaneous T-cell lymphoma," said Charles Morris, MB ChB, MRCP, chief medical officer at Allos Therapeutics. "Based on these results, Allos intends to continue investigating the role of FOLOTYN as an option for patients with cutaneous T-cell lymphomas."