A phase 2 study of panitumumab with irinotecan as salvage therapy in chemorefractory KRAS exon 2 wild-type metastatic colorectal cancer patients.

BACKGROUND: Targeted agents are standard treatment for RAS wild-type metastatic colorectal cancer in the first- and second-line settings. This phase 2 study determined the benefit of targeting the epidermal growth factor receptor (EGFR) with panitumumab plus irinotecan in irinotecan-refractory patients. METHODS: KRAS exon-2 wild-type patients failing prior irinotecan received panitumumab (6 mg/kg) and irinotecan (180 mg/m²) every 2 weeks. The primary endpoint was the overall response rate (ORR). Secondary endpoints included safety, progression-free survival (PFS) and overall survival (OS). KRAS exon-2 status was evaluated centrally, along with NRAS, BRAF mutations, epiregulin, amphiregulin, PTEN and EGFR copy number status, and correlated with efficacy. RESULTS: Sixty-one patients were treated. Among the 46 wild-type RAS patients, the ORR was 15.2% (seven partial responses), with median PFS of 3.8 months (95% CI 2.7-4.3) and median OS of 12.5 months (95% CI 6.7-15.9). Wild-type BRAF patients showed a 13.0% response rate. No significant correlations between response and baseline biomarker expression were identified. Common grade 3-4 adverse events were diarrhoea and rash (18.0% each), hypomagnesaemia and asthenia (8.2% each). CONCLUSIONS: The addition of panitumumab to irinotecan as salvage therapy is feasible but has limited activity in irinotecan-refractory metastatic colorectal cancer. No biomarkers predictive of response were identified.

Single-Agent Regorafenib in Metastatic Colorectal Cancer Patients with Any RAS or BRAF Mutation Previously Treated with FOLFOXIRI plus Bevacizumab (PREVIUM Trial).

LESSONS LEARNED: RAS- or BRAF-mutated metastatic colorectal cancers (mCRCs) progressing after first-line treatment have a poor prognosis.European and U.S. guidelines include the multikinase inhibitor regorafenib as a standard option for second-line therapy and beyond, based on the results of the randomized phase III CORRECT trial demonstrating improvement in survival.Although stopped prematurely for failing to accrue, the PREVIUM trial, the first prospective interventional study exploring regorafenib as second-line treatment for patients with mCRC bearing RAS or BRAF mutations, failed to demonstrate clinical activity in the population analyzed. BACKGROUND: Patients with RAS- or BRAF-mutated (mut) metastatic colorectal cancer (mCRC) progressing on first-line bevacizumab plus 5-FU/irinotecan/oxaliplatin (FOLFOXIRI) have a poor prognosis. We aimed to assess the efficacy and safety of regorafenib in this population. METHODS: Regorafenib was administered daily for 3 weeks of each 4-week cycle until disease progression or other reason. The primary endpoint was 6-month progression-free survival (PFS). RESULTS: KRAS, NRAS, or BRAF was mutated in mCRC samples in 60%, 20%, and 13% of patients, respectively. Median time from initial diagnosis of metastases to the start of regorafenib and treatment duration was 13.8 months and 7 weeks, respectively. Reasons for discontinuation included disease progression (80%), investigator decision (13%), and adverse events (AEs; 7%). Seven patients (47%) required dose reduction, mostly for asthenia (43%). The most common regorafenib-related grade 3 AEs were asthenia (33%), dysphonia (13%), and hypertension (13%) (Table 1). There were no grade 4 toxicities. No patient was progression-free at 6 months. Median PFS, time to progression (TTP), and overall survival (OS) were 2.2, 2.0, and 3.3 months, respectively. CONCLUSION: Although stopped prematurely for failing to accrue, in the population analyzed, regorafenib failed to demonstrate clinical activity in KRAS- or BRAF-mutated mCRC with progression following first-line with FOLFOXIRI plus bevacizumab, although tolerability was acceptable. Our trial suggests that exploring regorafenib efficacy in an earlier line of therapy should not be undertaken without better population refinement.

Phase I/II trial of sequential treatment of nab-paclitaxel in combination with gemcitabine followed by modified FOLFOX chemotherapy in patients with untreated metastatic exocrine pancreatic cancer: Phase I results.

BACKGROUND: Although occasioned through different mechanisms, the potential neurotoxicity and also haematological toxicity of nab-paclitaxel and oxaliplatin-based chemotherapy regimen were studied in this trial, which aimed to determine the maximum-tolerated dose (MTD) and to evaluate safety and efficacy of the combination in a sequential regimen of nab-paclitaxel, gemcitabine (GEM) and modified FOLFOX (mFOLFOX) in untreated patients with metastatic pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: Treatment consisted of nab-paclitaxel (125/100 mg/m2) plus GEM (1000/800 mg/m2) on days 1, 8 and 15, followed by mFOLFOX (oxaliplatin [85/75/65 mg/m2], 5-FU bolus [400/300/200 mg/m2], 5-FU infusion [2400/2000/1600 mg/m2]) on day 28, of a 42-day cycle. Patients were enrolled at the highest dose level with a subsequent 3 + 3 dose de-escalation plan. RESULTS: Eleven patients (median age = 61, 64% with performance status [PS] = 1) were eligible. All patients received the highest dose level. No de-escalation was needed. A dose-limiting toxicity was reported, an upper gastrointestinal haemorrhage. The MTD was nab-paclitaxel 125 mg/m2, GEM 1000 mg/m2, oxaliplatin 85 mg/m2, 5-FU bolus 400 mg/m2 and 5-FU infusion 2400 mg/m2. Common all-grade toxicities were neutropenia (73%), anaemia (55%), thrombocytopenia (55%) and asthenia (55%). Other relevant toxicities were paraesthesia (46%), nausea (36%), dysesthesia (27%) and pyrexia (27%). Objective response rate was 50% and disease control rate was 80%. CONCLUSIONS: The regimen of nab-paclitaxel plus GEM followed by mFOLFOX showed favourable safety and tolerability profiles with significant anti-tumor activity. More data are being achieved in a randomised phase II trial, to confirm efficacy rates and dismiss long-term neurotoxicity concerns regarding the sequencing of nab-paclitaxel and oxaliplatin.