Pharmacokinetics and safety of erenumab in pediatric patients with migraine: A phase I, randomized, open-label, multiple-dose study.

Erenumab, a fully human monoclonal antibody targeting the calcitonin gene-related peptide receptor, is efficacious and safe for prevention of attacks of migraine in adults. This phase I, randomized, open-label, multiple-dose study evaluated the safety, tolerability, and pharmacokinetics (PK) of erenumab in children and adolescents with migraine. The initial treatment phase lasted 12 weeks, followed by an optional 40-week extension phase for adolescents. Primary end points were PK of erenumab, incidence of treatment-emergent adverse events (TEAEs), and changes in clinical and laboratory assessments. Participants received erenumab 35 mg (n = 4), 70 mg (n = 17), or 140 mg (n = 32) q4w. The mean age was 14.1 years. Of the 53 participants, 48 (90.6%) completed the initial treatment phase and 36 (67.9%) received erenumab during the extension phase. Mean exposures to erenumab based on the maximum observed concentration and the area under the drug concentration-time curve during the dosing interval increased approximately dose-proportionally. A total of 42 participants (79.2%) reported TEAEs (307.2 per 100 participant-years); and four (7.5%) reported serious TEAEs not considered treatment-related. The most common TEAEs were upper respiratory tract infection, headache, and vomiting. No clinically significant changes were reported in vital signs, electrocardiograms, and laboratory and neurological assessments. Overall, the observed PK profile of erenumab in children and adolescents with migraine is consistent with that in adults when body weight differences are taken into consideration. The safety profile of erenumab in children and adolescents is consistent with that in adults.

Efficacy of Erenumab for Migraine Prevention in Japanese Patients with Episodic and Chronic Migraine: Results of a Post-Hoc Pooled Analysis.

INTRODUCTION: Erenumab, a fully human monoclonal antibody against the calcitonin gene-related peptide receptor, is approved in Japan for the prevention of adult migraine. This post-hoc analysis evaluated the efficacy of erenumab in Japanese patients with low-frequency episodic migraine (LFEM) versus those with high-frequency episodic migraine (HFEM) and chronic migraine (CM). METHODS: A pooled analysis of data from the 24-week double-blind treatment phases (DBTPs) of phase 2 and 3 studies evaluated the efficacy of once-monthly erenumab 70 mg in Japanese patients. Patients were categorized into subgroups by monthly migraine days (MMD): LFEM and HFEM/CM. The main efficacy outcomes were change from baseline in MMD, acute migraine-specific medication treatment days (MSMD), and six-item Headache Impact Test (HIT-6™) scores. RESULTS: Patients with migraine (n = 532) were included in the analysis (LFEM, n = 215; HFEM, n = 215; CM, n = 102). Overall, mean age was 44 years, 86.5% were female, and 63.3-88.2% had used or were taking migraine preventive treatment at baseline. Throughout the DBTP, the placebo-adjusted mean change from baseline in MMD, MSMD, and HIT-6 scores with erenumab was similar across LFEM and HFEM/CM subgroups. The proportion of patients achieving at least 50% or 75% reduction from baseline in MMD and MSMD was similar across migraine frequency groups. Reduction in MMD moderately correlated with improvement in HIT-6 scores in the LFEM and HFEM/CM groups. Furthermore, the proportion of patients converting from HFEM/CM to LFEM during the DBTP was higher in the erenumab group than in the placebo. CONCLUSION: In Japanese patients with different migraine frequencies, erenumab treatment resulted in significant improvements in MMD, MSMD, and headache impact. This pooled analysis of data from phase 2 and 3 studies increases confidence that erenumab is efficacious in patients with high MMD, which is associated with increased disability.

Long-term efficacy and safety of erenumab in Japanese patients with episodic and chronic migraine: results from a 28-week open-label treatment period of a randomised trial.

OBJECTIVES: To evaluate the 1-year efficacy and safety of once-monthly erenumab 70 mg following a 24-week double-blind treatment period (DBTP) of a phase III randomised study of Japanese patients with episodic migraine (EM) or chronic migraine (CM). DESIGN: Multicentre open-label study. SETTING: A total of 41 centres in Japan. PARTICIPANTS: Patients completing the DBTP continued into the 28-week open-label treatment period (OLTP). 254 of 261 (97.3%) randomised patients continued into the OLTP; 244 (93.5%) completed treatment. INTERVENTIONS: Once-monthly subcutaneous erenumab 70 mg. MAIN OUTCOME MEASURES: Changes from baseline in monthly migraine days (MMD) and monthly acute migraine-specific medication treatment days (MSMD) reported via patient eDiary; proportion of ≥50% and ≥75% responders in MMD reduction from baseline; incidence and exposure-adjusted incidence of treatment-emergent adverse events (TEAEs). RESULTS: At week 24 of the DBTP, the mean (SE) change from baseline in MMD for the erenumab group was -3.8 (0.4) days (EM, -3.0 (0.4); CM, -5.2 (0.8)); in MSMD, -2.6 (0.4) days (EM, -2.1 (0.4); CM, -3.4 (0.7)). At the end of the OLTP (52 weeks postbaseline), the mean (SE) change from baseline in MMD was -4.7 (0.3) days (EM, -3.4 (0.3); CM, -6.9 (0.6)); in MSMD, -3.3 (0.3) days (EM, -2.4 (0.3); CM, -4.6 (0.5)). The proportion of ≥50% responders for MMD reduction in the erenumab group was 34.1% at week 24; 44.4% at week 52. The exposure-adjusted incidence of TEAEs was 219.7 per 100 patient-years during the OLTP (DBTP, 251.0 for the erenumab group). The most common TEAEs during the OLTP were nasopharyngitis, constipation and influenza. No new safety concerns were identified. CONCLUSIONS: Erenumab treatment was associated with reduced migraine frequency in Japanese patients with EM or CM for up to 1 year. Overall safety results from the OLTP were consistent with DBTP results. TRIAL REGISTRATION NUMBER: NCT03812224.

Efficacy of erenumab in chronic migraine patients with and without ictal allodynia.

BACKGROUND: Ictal cutaneous allodynia, common in chronic migraine, is associated with reduced responses to acute treatment with triptans. Allodynia's impact on the efficacy of newer preventive treatments such as erenumab is unknown. METHODS: Post-hoc subgroup analysis of a double-blind, randomized, placebo-controlled 12-week study of erenumab in chronic migraine, contrasting those with no allodynia with those with moderate-severe allodynia assessed with the Allodynia Symptom Checklist-12, was undertaken. RESULTS: Of 648 randomized individuals with baseline Allodynia Symptom Checklist-12 scores, 386 (59.6%) had no allodynia and 153 (23.6%) had moderate-to-severe allodynia. Mean (standard deviation) baseline monthly migraine days were 17.6 (4.8) and 18.9 (4.3), respectively. Compared to placebo, the erenumab group had greater reductions in monthly migraine days and monthly acute migraine-specific medication days in both no allodynia and allodynia subgroups. Mean (95% confidence interval) treatment differences in change from baseline for monthly migraine days at week 12 were -2.5 (-3.7, -1.4) in the no allodynia subgroup and -3.3 (-5.3, -1.3) in the moderate-severe allodynia subgroup. Change in acute migraine-specific medication days were -3.3 (-4.3, -2.3) and -2.5 (-4.3, -0.8), respectively. CONCLUSIONS: Erenumab's efficacy in reducing monthly migraine days and acute migraine-specific medication days in chronic migraine was not impacted by the presence of moderate-severe ictal allodynia.Trial registration: ClinicalTrials.gov NCT02066415.

Impact of Primary Tumour Location and Early Tumour Shrinkage on Outcomes in Patients with RAS Wild-Type Metastatic Colorectal Cancer Following First-Line FOLFIRI Plus Panitumumab.

OBJECTIVE: Data from a trial of first-line panitumumab plus FOLFIRI (folinic acid, infusional 5-fluorouracil and irinotecan) in metastatic colorectal cancer were retrospectively analysed to investigate the effects of primary tumour location and early tumour shrinkage on outcomes. METHODS: Patients with RAS wild-type metastatic colorectal cancer from a single-arm, open-label phase II study (NCT00508404) were included. Tumours located from the splenic flexure to rectum and in the caecum to transverse colon were defined as left- and right-sided, respectively. Baseline characteristics were summarised by primary tumour location and the effects of primary tumour location on outcomes-including objective response rate, resection rate, depth of response, duration of response and progression-free survival-were analysed. Progression-free survival and objective response rate were analysed by early tumour shrinkage status. RESULTS: Primary tumour location was determined in 52/69 (75%) patients with RAS wild-type metastatic colorectal cancer; 45 (87%) had left-sided disease. Median progression-free survival was longer in patients with left-sided tumours (11.2 vs. 7.2 months for right-sided disease) and more of these patients experienced early tumour shrinkage ≥ 30% (53% vs. 29%). Early tumour shrinkage ≥ 30% was associated with improved progression-free survival irrespective of tumour location. More patients with early tumour shrinkage ≥ 30% achieved a partial or complete response. Objective response rate, duration of response, depth of response and resection rates were similar in patients with left- and right-sided tumours. CONCLUSIONS: This analysis has confirmed a prognostic effect of primary tumour location in patients with RAS wild-type metastatic colorectal cancer receiving first-line panitumumab plus FOLFIRI. Early tumour shrinkage was associated with improved progression-free survival irrespective of tumour location. In right-sided disease, early tumour shrinkage may identify a subgroup of patients who might respond to panitumumab. CLINICALTRIALS. GOV IDENTIFIER: NCT00508404.

Prospective Observational Cohort Study to Describe the Use of Panitumumab in Combination with Chemotherapy in Real-World Clinical Practice for Patients with Wild-Type RAS mCRC.

INTRODUCTION: This study aimed to better understand panitumumab use in real-life clinical practice in first- and second-line treatment of metastatic colorectal cancer in five European countries. METHODS: This is a combined analysis of two observational, non-interventional prospective cohort studies, one of which was conducted in Germany and France, the other in Bulgaria, Czech Republic, and Hungary. The studies observed patients with wild-type [Kirsten] rat sarcoma viral oncogene homolog ([K]RAS/RAS) metastatic colorectal cancer (mCRC), who had been treated with panitumumab in combination with fluorouracil, leucovorin, and oxaliplatin (FOLFOX) in the first line or with panitumumab combined with fluorouracil, leucovorin, and irinotecan (FOLFIRI) in the second line following fluoropyrimidine-based chemotherapy. The planned duration of observation was 12 months from the first dose of panitumumab. RESULTS: A total of 332 patients treated with panitumumab + FOLFOX in the first line and 94 patients treated with panitumumab + FOLFIRI in the second line were analyzed. The median number of panitumumab infusions was 10.0 in first-line FOLFOX patients and 11.5 in second-line FOLFIRI patients; the median duration of panitumumab exposure was 5.7 and 6.9 months, respectively. The unadjusted overall response rate (complete or partial response) in patients with available post-baseline response assessment (n = 290) was 51.7% in first-line FOLFOX and 44.9% in second-line FOLFIRI patients. In the first-line setting, resectability was achieved in 9.3%. Reported hospitalizations were mostly cancer-related visits such as scheduled anticancer treatment administrations, tumor assessment visits, or interventions. The majority of adverse drug reactions were skin disorders, with 75.3% in first-line FOLFOX patients and 72.3% in second-line FOLFIRI patients. CONCLUSION: Overall, the study results show that treatment patterns, clinical efficacy, and the safety profile of panitumumab in routine clinical practice were comparable to those in randomized controlled trials. The relatively low skin toxicity rate could be attributed to increasing experience in managing panitumumab-associated rash and some degree of underreporting. FUNDING: Amgen.

Panitumumab-based maintenance after oxaliplatin discontinuation in metastatic colorectal cancer: A retrospective analysis of two randomised trials.

Panitumumab is approved for RAS wild-type metastatic colorectal cancer and was evaluated in Phase III (PRIME, NCT00364013) and Phase II (PEAK, NCT00819780) first-line randomised studies. This retrospective analysis of these trials investigated efficacy and toxicity of panitumumab-based maintenance after oxaliplatin discontinuation in RAS wild-type patients. First-line regimens were FOLFOX4 ± panitumumab in PRIME and mFOLFOX6 plus panitumumab or mFOLFOX6 plus bevacizumab in PEAK. Outcomes included median progression-free survival (PFS) and overall survival (OS), from randomisation and oxaliplatin discontinuation, and toxicity. Overall, median duration of panitumumab plus 5-fluorouracil/leucovorin (5-FU/LV) maintenance was 21 (interquartile range: 11-41) weeks; that of 5-FU/LV ± bevacizumab maintenance was 16 (6-31) weeks. Median OS from randomisation was 40.2 (95% confidence interval: 30.3-50.4) and 39.1 (34.2-63.0) months for panitumumab plus 5-FU/LV maintenance and 24.1 (17.7-33.0) and 28.9 (21.0-32.0) months for 5-FU/LV ± bevacizumab maintenance in PRIME and PEAK, respectively. Median PFS from randomisation was 16.6 (11.3-23.6) and 15.4 (11.6-18.4) months for panitumumab plus 5-FU/LV maintenance and 12.6 (9.4-16.2) and 13.1 (9.5-16.6) months for 5-FU/LV ± bevacizumab maintenance in PRIME and PEAK, respectively. From oxaliplatin discontinuation, median OS was 33.9 (24.7-42.8) and 33.5 (24.5-54.9) months for panitumumab plus 5-FU/LV maintenance and 16.4 (12.4-24.1) and 23.3 (15.7-26.3) months for 5-FU/LV ± bevacizumab maintenance in PRIME and PEAK, respectively; PFS was 11.7 (7.8-19.2) and 9.7 (5.8-14.8) months and 7.1 (5.6-10.2) and 7.0 (3.9-10.6) months, respectively. The most frequently reported adverse events were rash, fatigue and diarrhoea. Maintenance of panitumumab plus 5-FU/LV after oxaliplatin discontinuation was well tolerated and may be an acceptable treatment paradigm for patients demonstrating a good response to first-line treatment. Prospective studies are warranted.

Relationships between tumour response and primary tumour location, and predictors of long-term survival, in patients with RAS wild-type metastatic colorectal cancer receiving first-line panitumumab therapy: retrospective analyses of the PRIME and PEAK clinical trials.

BACKGROUND: Data from two trials of panitumumab in metastatic colorectal cancer (mCRC) were retrospectively analysed to investigate the effects of primary tumour location on early-tumour shrinkage (ETS) and depth of response (DpR), and identify factors predicting long-term survival. METHODS: Patients with RAS wild-type mCRC from PRIME (NCT00364013) and PEAK (NCT00819780) were included. ETS was defined as a ≥30% reduction in the sum-of-the-longest-diameters of measurable target lesions at eight weeks. DpR was the maximum percentage change from baseline to nadir in patients with shrinkage. Univariate and multivariate logistic analyses of short- versus long-term survivor data were performed. RESULTS: A total of 435/559 (78%) patients had left-sided disease. Of these, a higher proportion of patients treated with panitumumab versus comparator achieved ETS (PRIME: 62% vs. 36%; PEAK: 58% vs. 41%); median DpR was also higher with panitumumab (PRIME: 59% vs. 49%; PEAK: 70% vs. 48%). In pooled analyses of the studies, more patients with right-sided disease achieved ETS if treated with panitumumab than comparator (39% vs. 29%). Panitumumab treatment consistently predicted long-term survival. CONCLUSIONS: First-line panitumumab was associated with improved ETS and DpR vs. comparator in patients with left-sided mCRC. ETS may identify a subgroup of patients with right-sided disease who might respond to panitumumab.

Effect of Primary Tumor Location on Second- or Later-line Treatment Outcomes in Patients With RAS Wild-type Metastatic Colorectal Cancer and All Treatment Lines in Patients With RAS Mutations in Four Randomized Panitumumab Studies.

BACKGROUND: The primary tumor location has a prognostic impact in metastatic colorectal cancer (mCRC). We report the results from retrospective analyses assessing the effect of tumor location on prognosis and efficacy of second- and later-line panitumumab treatment in patients with RAS wild-type (WT) mCRC and on prognosis in all lines of treatment in patients with RAS mutant (MT) mCRC. PATIENTS AND METHODS: RAS WT data (n = 483) from 2 randomized phase III panitumumab trials (ClinicalTrials.gov identifiers, NCT00339183 and NCT00113763) were analyzed for treatment outcomes stratified by tumor location. The second analysis assessed the effect of tumor location in RAS MT patients (n = 1205) from 4 panitumumab studies (ClinicalTrials.gov identifiers, NCT00364013, NCT00819780, NCT00339183, and NCT00113763). Primary tumors located in the cecum to transverse colon were coded as right-sided; those located from the splenic flexure to the rectum were coded as left-sided. RESULTS: Of all patients, the tumor location was ascertained for 83% to 88%; 71% to 77% of patients had left-sided tumors. RAS WT patients with right-sided tumors did worse for all efficacy parameters compared with those with left-sided tumors. The patients with left-sided tumors had better outcomes with panitumumab than with the comparator treatment. Because of the low patient numbers, no conclusions could be drawn for right-sided mCRC. The prognostic effect of tumor location on survival was unclear for RAS MT patients. CONCLUSION: These retrospective analyses have confirmed that RAS WT right-sided mCRC is associated with a poor prognosis, regardless of the treatment. RAS WT patients with left-sided tumors benefitted from the addition of panitumumab in second or later treatment lines. Further research is warranted to determine the optimum management of right-sided mCRC and RAS MT tumors.

Author Correction: Exploratory analyses assessing the impact of early tumour shrinkage and depth of response on survival outcomes in patients with RAS wild-type metastatic colorectal cancer receiving treatment in three randomised panitumumab trials.

The authors would like to include the following changes in the published article.

Survival Outcomes in Patients With RAS Wild Type Metastatic Colorectal Cancer Classified According to Köhne Prognostic Category and BRAF Mutation Status.

BACKGROUND: Köhne prognostic score is used to classify patients with metastatic colorectal cancer (mCRC) as high, intermediate, or low risk. Using data from 2 phase III trials, we analyzed survival in patients categorized according to Köhne prognostic category and virus-induced rapidly accelerated fibrosarcoma murine sarcoma viral oncogene homolog B (BRAF) mutation. PATIENTS AND METHODS: PRIME (Panitumumab Randomized Trial In Combination With Chemotherapy for Metastatic Colorectal Cancer to Determine Efficacy) (first-line) and 20050181 (second-line) were studies of chemotherapy with or without panitumumab. Progression-free survival (PFS) and overall survival (OS) were analyzed retrospectively in rat sarcoma viral oncogene homolog (RAS) wild type (WT) and RAS WT+BRAF WT mCRC in each Köhne category, and in BRAF mutant (MT) mCRC. RESULTS: In PRIME (n = 495) and 20050181 (n = 420), 53 (11%) and 44 (10%) patients, respectively, had BRAF MT mCRC. Of the RAS WT+BRAF WT/unknown populations, 85/267/90 and 82/211/83 were categorized as high/medium/low risk, respectively. PFS and OS hazard ratios (HRs), adjusted for Köhne group, for patients with RAS WT + BRAF WT/unknown mCRC favored panitumumab with chemotherapy versus chemotherapy alone in both studies. In PRIME, the PFS HR was 0.74 (95% confidence interval [CI], 0.61-0.90) and OS HR was 0.78 (95% CI, 0.64-0.95). In 20050181, PFS and OS HRs were 0.80 (95% CI, 0.65-0.99) and 0.78 (95% CI, 0.62-0.99), respectively. Median PFS and OS were lower in patients with BRAF MT mCRC than in any of the 3 risk categories for patients with RAS WT+BRAF WT/unknown mCRC. CONCLUSION: During first- and second-line treatment, Köhne prognostic score allows accurate risk classification in RAS WT mCRC. BRAF MT mCRC should be classified as high risk regardless of other parameters. Panitumumab with chemotherapy might provide survival benefits versus chemotherapy alone in RAS WT and RAS WT+BRAF WT/unknown mCRC, overall and across risk categories.

Exploratory analyses assessing the impact of early tumour shrinkage and depth of response on survival outcomes in patients with RAS wild-type metastatic colorectal cancer receiving treatment in three randomised panitumumab trials.

PURPOSE: To report exploratory analyses of early tumour shrinkage (ETS) and depth of response (DpR) in patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC), receiving the first-line treatment in three randomised panitumumab trials. METHODS: Data from the PRIME (NCT00364013), PEAK (NCT00819780) and PLANET (NCT00885885) studies were included. Median DpR, the proportion of patients achieving ETS ≥ 20% or ≥ 30% at week 8, and the impact of ETS and DpR (including by category) on outcome were analysed. Factors associated with ETS and DpR and the optimal ETS/DpR cut-off values for predicting improved overall survival (OS) were assessed. RESULTS: Overall, 505, 170 and 53 patients had RAS WT mCRC in PRIME, PEAK and PLANET, respectively. Patients receiving panitumumab had higher ETS rates (≥ 30%: PRIME 59% vs. 38%; PEAK 64% vs. 45%) and greater DpR (PRIME: 54% vs. 46%; PEAK: 65% vs. 46%) than those receiving treatment without panitumumab. In multiple regression analyses, panitumumab treatment, liver-only metastases and WT BRAF status were consistently associated with improved ETS and DpR outcomes. Irrespective of treatment, ETS and DpR were associated with improved progression-free survival, overall survival and resection rates; most resections occurred in patients in the two highest DpR categories. In PRIME and PEAK, respectively, the optimal cut-offs for predicting improved OS were 32 and 34% for ETS, and 59 and 70% for DpR. CONCLUSIONS: These exploratory analyses suggest that panitumumab is associated ETS and DpR benefits in patients with RAS WT mCRC and that achieving these endpoints during first-line treatment is linked with favourable outcomes.

Quality of life during first-line FOLFOX4±panitumumab in RAS wild-type metastatic colorectal carcinoma: results from a randomised controlled trial.

INTRODUCTION: Metastatic colorectal cancer is rarely curable. Improving quality of life is therefore a key treatment goal. We report quality of life for patients with RAS wild-type metastatic colorectal cancer in the PRIME study. METHODS: A randomised phase 3 open-label study of first-line panitumumab+FOLFOX4 vs FOLFOX4 enrolled adults with untreated metastatic colorectal cancer and an Eastern Cooperative Oncology Group performance status of 0-2. This analysis includes patients with wild-type RAS tumours (n=505). Quality of life (prespecified end point) was assessed using the EuroQoL 5-domain health state index and overall health rating in all patients and by early tumour shrinkage status (≥30% reduction in size by week 8; exploratory end point). Differences in quality of life were assessed using analysis of covariance and a mixed-effect piecewise linear model, and were also analysed by skin toxicity severity. RESULTS: There were no statistically significant differences between treatment arms from baseline to progression or to discontinuation. Grade 3+ skin toxicity was reported by 38% of patients receiving panitumumab+FOLFOX4 and 2% receiving FOLFOX4 alone. There were no significant differences in quality of life between patients with grade 0-2 skin toxicity and those with grade 3+ skin toxicity. More patients receiving panitumumab+FOLFOX4 vs FOLFOX4 had early tumour shrinkage (p<.001). In patients with tumour symptoms at baseline, there were statistically significant improvements in quality of life in those with early tumour shrinkage versus those without early tumour shrinkage. CONCLUSIONS: Addition of panitumumab to FOLFOX4 in first-line therapy for metastatic colorectal cancer prolongs survival and has no negative effect on overall quality of life compared with FOLFOX4 alone. Specific quality of life assessments for skin toxicity should be included in study designs to better define the direct effect of these adverse events. TRIAL REGISTRATION NUMBER: NCT00364013.

A study-level meta-analysis of efficacy data from head-to-head first-line trials of epidermal growth factor receptor inhibitors versus bevacizumab in patients with RAS wild-type metastatic colorectal cancer.

BACKGROUND: Head-to-head trials comparing first-line epidermal growth factor receptor inhibitor (EGFRI) versus vascular endothelial growth factor inhibitor (bevacizumab) therapy yielded differing results, and debate remains over optimal first-line therapy for patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC). METHODS: A PubMed search identified first-line mCRC trials comparing EGFRI plus chemotherapy versus bevacizumab plus chemotherapy; data were subsequently updated using recent congress presentations. This study-level meta-analysis estimated the overall survival (OS) treatment effect of first-line chemotherapy plus EGFRIs or bevacizumab in patients with RAS WT mCRC. Secondary end-points were progression-free survival (PFS), objective response rate (ORR), resection rate and safety. Early tumour shrinkage (ETS) of ≥20% at week 8 was an exploratory end-point. RESULTS: Three trials comprising data from 1096 patients with RAS WT mCRC were included. OS (hazard ratio [HR]: 0.80 [95% confidence interval: 0.68-0.93]), ORR (odds ratio [OR]: 0.57) and ETS (OR: 0.48) favoured EGFRIs plus chemotherapy versus bevacizumab plus chemotherapy. PFS (HR: 0.98) and resections (OR: 0.93) were similar between treatments. For patients with KRAS exon 2 WT/'other' RAS mutant mCRC the OS HR was 0.70. A safety meta-analysis was not possible due to a lack of data; in the individual studies, skin toxicities and hypomagnesaemia were more common with EGFRIs, nausea and hypertension were more common with bevacizumab. CONCLUSIONS: This meta-analysis supports a potential benefit for first-line EGFRI plus chemotherapy versus bevacizumab plus chemotherapy with respect to OS, ORR and ETS in patients with RAS WT mCRC. A patient-level meta-analysis is awaited.

Skin toxicity and quality of life during treatment with panitumumab for RAS wild-type metastatic colorectal carcinoma: results from three randomised clinical trials.

PURPOSE: Epidermal growth factor receptor inhibitors such as panitumumab are associated with characteristic skin toxicities. We summarise data from three panitumumab clinical trials to investigate the potential impact of skin toxicity on quality of life (QoL) in patients with metastatic colorectal cancer (mCRC). METHODS: The studies were randomised, open-label trials comparing standard treatment (first-line FOLFOX4 [n = 456], second-line FOLFIRI [n = 381], or best supportive care [n = 114]) with or without panitumumab in adults with KRAS/NRAS (RAS) wild-type mCRC. QoL was assessed using the EuroQoL 5-domain health state index (HSI) and overall health rating (OHR) measures. Impact of skin toxicity on changes in QoL scores was estimated using a linear mixed-effects model. Worst skin toxicity was defined in separate models as a subgroup variable or as a measure over time. RESULTS: Regardless of analysis method, there were no statistically significant differences between the panitumumab and comparator arms in any of the studies in terms of change in HSI or OHR scores. There were no statistically significant differences in QoL outcomes between patients with worst skin toxicity grade <3 and those with grade ≥3. In addition, there were no statistically significant differences between the panitumumab and comparator arms in subgroups of patients with worst skin toxicity of grade <3 and ≥3. CONCLUSIONS: Addition of panitumumab to chemotherapy in RAS wild-type mCRC has no statistically significant negative effect on overall QoL, despite skin toxicity. Skin toxicity of worst grade ≥3 appeared to have similar impact on QoL as skin toxicity of grade <3.

Analysis of KRAS/NRAS Mutations in a Phase III Study of Panitumumab with FOLFIRI Compared with FOLFIRI Alone as Second-line Treatment for Metastatic Colorectal Cancer.

PURPOSE: We evaluated the influence of RAS mutation status on the treatment effect of panitumumab in a prospective-retrospective analysis of a randomized, multicenter phase III study of panitumumab plus fluorouracil, leucovorin, and irinotecan (FOLFIRI) versus FOLFIRI alone as second-line therapy in patients with metastatic colorectal cancer (mCRC; ClinicalTrials.gov, NCT0039183). EXPERIMENTAL DESIGN: Outcomes were from the study's primary analysis. RAS mutations beyond KRAS exon 2 (KRAS exons 3, 4; NRAS exons 2, 3, 4; BRAF exon 15) were detected by bidirectional Sanger sequencing in wild-type KRAS exon 2 tumor specimens. Progression-free survival (PFS) and overall survival (OS) were coprimary endpoints. RESULTS: The RAS ascertainment rate was 85%; 18% of wild-type KRAS exon 2 tumors harbored other RAS mutations. For PFS and OS, the hazard ratio (HR) for panitumumab plus FOLFIRI versus FOLFIRI alone more strongly favored panitumumab in the wild-type RAS population than in the wild-type KRAS exon 2 population [PFS HR, 0.70 (95% confidence interval [CI], 0.54-0.91); P = 0.007 vs. 0.73 (95% CI, 0.59-0.90); P = 0.004; OS HR, 0.81 (95% CI, 0.63-1.03); P = 0.08 vs. 0.85 (95% CI, 0.70-1.04); P = 0.12]. Patients with RAS mutations were unlikely to benefit from panitumumab. Among RAS wild-type patients, the objective response rate was 41% in the panitumumab-FOLFIRI group versus 10% in the FOLFIRI group. CONCLUSIONS: Patients with RAS mutations were unlikely to benefit from panitumumab-FOLFIRI and the benefit-risk of panitumumab-FOLFIRI was improved in the wild-type RAS population compared with the wild-type KRAS exon 2 population. These findings support RAS testing for patients with mCRC. Clin Cancer Res; 21(24); 5469-79. ©2015 AACR.See related commentary by Salazar and Ciardiello, p. 5415.

Impact of early tumour shrinkage and resection on outcomes in patients with wild-type RAS metastatic colorectal cancer.

BACKGROUND: Tumour shrinkage (TS) increases the possibility of resection in metastatic colorectal cancer (mCRC) and may improve tumour-related symptoms. Here we report prespecified secondary response-related end-points and exploratory TS/resection outcomes for patients with RAS wild-type (WT) tumours (no mutations in KRAS/NRAS exons 2/3/4) from the PRIME study (NCT00364013). METHODS: PRIME was a randomised phase 3 study comparing first-line panitumumab+FOLFOX4 versus FOLFOX4 in mCRC patients. Tumour response analyses were conducted to compare response rates and their impact on survival outcomes. RESULTS: Overall, 505 patients had RAS WT mCRC. More patients receiving panitumumab+FOLFOX4 versus FOLFOX4 had ⩾30% (59% versus 38%; P<0.001) or ⩾20% (72% versus 57%; P<0.001) TS at week 8 (early TS); consistent TS benefits were observed over the first ∼40weeks of treatment. Objective response rate (P=0.003), duration of response (P=0.0027), depth of response (P=0.0149), progression-free survival (PFS; P=0.0015) and overall survival (OS; P=0.0057) were improved in the panitumumab+FOLFOX4 group. Both early TS and resection were associated with improved PFS and OS. 2-year OS rates for patients who did (n=64) versus did not (n=441) undergo resection were 88% versus 40%; 2-year OS rates for patients who did (n=45) versus did not (n=460) undergo complete resection were 96% versus 41%. CONCLUSIONS: More patients receiving panitumumab+FOLFOX4 versus FOLFOX4 had ⩾30% or ⩾20% TS at week 8; PFS and OS were also improved with panitumumab+FOLFOX4. The clinical value of achieving early TS in mCRC warrants further investigation.