Madhavan V. Pillai

Skin Toxicity Evaluation Protocol With Panitumumab (STEPP), a Phase II, Open-Label, Randomized Trial Evaluating the Impact of a Pre-Emptive Skin Treatment Regimen on Skin Toxicities and Quality of Life in Patients With Metastatic Colorectal Cancer

PURPOSE Panitumumab, a fully human monoclonal antibody targeting the epidermal growth factor receptor (EGFR), is approved in the United States and Europe for the treatment of refractory metastatic colorectal cancer (mCRC). Skin toxicities are the most common adverse events with EGFR inhibitors. This is the first study designed to examine differences between pre-emptive and reactive skin treatment for specific skin toxicities in patients with mCRC for any EGFR inhibitor. PATIENTS AND METHODS Patients receiving panitumumab-containing therapy were randomly assigned 1:1 to pre-emptive or reactive treatment (after skin toxicity developed). Pre-emptive treatment included use of skin moisturizers, sunscreen, topical steroid, and doxycycline. The primary end point of the study was the incidence of protocol-specified >or= grade 2 skin toxicities during the 6-week skin treatment period. Quality of life (QOL) was assessed with the Dermatology Life Quality Index (DLQI). RESULTS Of 95 enrolled patients, 48 received pre-emptive treatment, and 47 received reactive treatment. The incidence of protocol-specified >or= grade 2 skin toxicities during the 6-week skin treatment period was 29% and 62% for the pre-emptive and reactive groups, respectively. Mean DLQI score change from baseline to week 3 was 1.3 points and 4.2 points in the pre-emptive and reactive groups, respectively. CONCLUSION The pre-emptive skin treatment regimen was well tolerated. The incidence of specific >or= grade 2 skin toxicities during the 6-week skin treatment period was reduced by more than 50% in the pre-emptive group compared with the reactive group. Patients in the pre-emptive group reported less QOL impairment than patients in the reactive group.

A Randomized, Placebo-Controlled Phase II Study Evaluating the Reduction of Neutropenia and Febrile Neutropenia in Patients With Colorectal Cancer Receiving Pegfilgrastim With Every-2-Week Chemotherapy

BACKGROUND Adding irinotecan and/or oxaliplatin to every-2-week 5-fluorouracil (5-FU)/leucovorin (LV) prolongs survival in patients with colorectal cancer (CRC) but increases neutropenia frequency. Pegfilgrastim is indicated to decrease infection as manifested by febrile neutropenia (FN) in patients receiving chemotherapy at > 14-day intervals. This randomized, placebo-controlled phase II study examined pegfilgrastim efficacy and safety in patients with CRC receiving every-2-week chemotherapy. PATIENTS AND METHODS Patients with CRC were randomized 1:1 to pegfilgrastim 6 mg or placebo administered per-cycle on day 4. Randomization was stratified by chemotherapy regimen (patients received every-2-week FOLFOX4 [5-FU/LV/oxaliplatin], FOLFIRI [5-FU/LV/irinotecan], or FOIL [5-FU/LV/oxaliplatin/irinotecan] at physician discretion). The primary endpoint was incidence of grade 3/4 neutropenia. Secondary endpoints included incidence of grade 3/4 FN and adverse events. After 4 cycles of study treatment, progression-free survival (PFS) and overall survival (OS) were followed for <or= 2 years in long-term follow-up. RESULTS Of 241 eligible patients analyzed, 118 were in the placebo and 123 in the pegfilgrastim group. In the treatment period, the odds ratio for grade 3/4 neutropenia for pegfilgrastim versus placebo was 0.19 (95% CI, 0.10-0.37; P < .001); grade 3/4 FN incidence was also significantly lower in pegfilgrastim-treated patients (2%) compared with placebo-treated patients (8%; P = .04). Pegfilgrastim was well tolerated, with leukocyte counts remaining stable during cycles 2-4. In long-term follow-up, both treatment groups had similar PFS and OS. CONCLUSION Pegfilgrastim was well tolerated in patients with CRC receiving every-2-week chemotherapy and significantly reduced neutropenia and FN compared with placebo, though FN was uncommon in both treatment groups. Results suggest that pegfilgrastim administration is feasible in CRC patients receiving every-2-week chemotherapy.

The Efficacy and Safety of Panitumumab Administered Concomitantly With FOLFIRI or Irinotecan in Second-Line Therapy for Metastatic Colorectal Cancer: The Secondary Analysis From STEPP (Skin Toxicity Evaluation Protocol With Panitumumab) by KRAS Status

BACKGROUND Panitumumab, a fully human monoclonal antibody targeting the epidermal growth factor receptor (EGFR), is used as monotherapy for chemorefractory metastatic colorectal cancer (mCRC) in patients with wild-type (WT) KRAS tumors. Although skin toxicities are the most common adverse events associated with EGFR inhibitors, the differences in efficacy and safety between pre-emptive and reactive skin treatment according to KRAS tumor status has not been reported. PATIENTS AND METHODS Eligible patients had mCRC with disease progression or unacceptable toxicity with first-line treatment containing fluoropyrimidine and oxaliplatin-based chemotherapy ± bevacizumab. Patients were randomized 1:1 to pre-emptive or reactive skin treatment (after skin toxicity developed). Patients received either panitumumab 6 mg/kg + FOLFIRI every 2 weeks or panitumumab 9 mg/kg + irinotecan every 3 weeks. Key study endpoints included overall response rate (ORR), overall survival, progression-free survival (PFS), and safety according to KRAS tumor status. RESULTS Eighty-seven (92%) of 95 enrolled patients had evaluable KRAS tumor status: 49 (56%) patients with WT and 38 (44%) patients with mutant (MT) KRAS tumors, respectively. The ORR was 16% and 8% for patients with WT and MT KRAS tumors, respectively. Median PFS was 5.5 and 3.3 months for patients with WT and MT KRAS tumors, respectively. The most commonly observed adverse events by KRAS tumor status included dermatitis acneiform and pruritus. CONCLUSION Panitumumab in combination with irinotecan-based chemotherapy has an acceptable toxicity profile in second-line therapy for mCRC. Numerical differences trending in favor of the patients with WT KRAS tumors were observed for most efficacy endpoints.