Noninferiority of cetuximab every-2-weeks versus standard once-weekly administration schedule for the first-line treatment of RAS wild-type metastatic colorectal cancer.

AIM: This study assessed whether cetuximab 500 mg/m2 administered every 2 weeks (Q2W), when combined with chemotherapy as a first-line (1L) treatment, was noninferior to the approved dose (400 mg/m2 followed by 250 mg/m2 once weekly [Q1W]) for overall survival (OS) in adults with RAS wild-type metastatic colorectal cancer (mCRC). METHODS: This pooled analysis included patients receiving 1L treatment with cetuximab Q1W or Q2W in combination with chemotherapy from post-authorisation studies with patient-level data available to the sponsor. Baseline characteristics were adjusted with a propensity score using inverse probability of treatment weighting (IPTW). Noninferiority in terms of OS was tested with a noninferiority margin for the hazard ratio (HR) of 1.25 using a Cox proportional hazards regression model. Secondary outcomes were progression-free survival (PFS), overall response rate (ORR) and rates of lung/liver metastases resection and serious adverse events. RESULTS: OS time was noninferior in the Q2W cohort (n = 554) compared to the Q1W cohort (n = 763), with a HR after IPTW (95% confidence interval) of 0.827 (0.715-0.956) and median OS times of 24.7 (Q1W) and 27.9 (Q2W) months. There were no major differences in PFS (HR: 0.915 [0.804-1.042]). The odds ratios (ORs) after IPTW for ORR (1.292 [1.031-1.617]) and the rates of lung/liver metastases resection (1.419 [1.043-1.932]) favoured the Q2W regimen. No differences were noted in the occurrence rate of any SAE between groups; the OR after IPTW was 1.089 (0.858-1.382). CONCLUSIONS: The cetuximab Q2W regimen was noninferior to the Q1W regimen for OS in the 1L treatment of mCRC.

A genotype-specific baseline score predicts post-treatment response to peginterferon alfa-2a in hepatitis B e antigen-negative chronic hepatitis B.

BACKGROUND: Peginterferon alfa-2a induces durable responses in some hepatitis B e antigen-negative patients, but robust pretreatment predictors are not available to identify likely responders. In this study we aimed to develop genotype-specific baseline scoring systems to predict response. METHODS: Data from 323 hepatitis B e antigen-negative peginterferon alfa-2a recipients from three studies were analyzed. Scoring systems were developed using generalized additive models and multiple logistic regression analysis. Response was defined as hepatitis B virus DNA <2000 IU/mL alone (virological response) or in combination with alanine aminotransferase normalization (combined response) 48 weeks post-treatment. RESULTS: Points were assigned to genotype B/C patients for: age, alanine aminotransferase ratio, genotype B or C, and hepatitis B surface antigen level; and to genotype D patients for age, hepatitis B surface antigen level and hepatitis B virus DNA level. Higher total scores (range 0-5 for B/C; 0-3 for D) indicated a higher likelihood of response. Among genotype B/C patients with scores of 0-1, 2 and ≥3, respectively, virological response rates were 16.7%, 25.8% and 70.2%, and combined response rates were 12.5%, 21.0% and 57.4%. Among genotype D patients with scores of 0-1, 2 and 3, respectively, virological response rates were 10.1%, 28.0% and 50.0%, and combined response rates were 7.8%, 28.0% and 33.3%. CONCLUSION: Genotype-specific baseline scoring systems can identify hepatitis B e antigen-negative patients with low or high likelihood of achieving sustained responses to peginterferon alfa-2a.

Serum Levels of Hepatitis B Surface Antigen Predict Severity of Fibrosis in Patients With E Antigen-Positive Chronic Hepatitis B.

BACKGROUND & AIMS: Noninvasive techniques are needed to assess hepatic fibrosis in patients with chronic hepatitis B. We developed a scoring system to determine the degree of fibrosis in patients with genotype B or genotype C hepatitis B virus (HBV) infection and positive for the hepatitis B e antigen. METHODS: We performed a retrospective study to identify baseline variables associated with the severity of fibrosis (METAVIR scores, F0-F4) in a large phase 3 clinical trial of predominantly Asian patients (n = 710), using multivariate logistic regression analyses. Significant variables were used to construct predictive models using optimal cut-off values. The final model was validated in similar patients from a large phase 4 clinical trial (n = 465). RESULTS: We developed 2 prediction scoring systems (PSs). PS1 analyzed data on HBV genotype (B vs. C), patient age (<30 vs. ≥30 y), level of hepatitis B surface antigen (≤17,500 vs. >17,500 IU/mL), and level of alanine aminotransferase (≤3-fold vs. >3-fold the upper limit of normal). PS2 analyzed data on only age and level of hepatitis B surface antigen. PS1 identified patients with F0 to F1 vs. F2 to F4 fibrosis with more than 87% specificity and a positive predictive value greater than 75; it identified patients with F0 to F2 vs. F2 to F4 fibrosis with approximately 95% specificity and a positive predictive value (PPV) of approximately 97%. PS2 identified patients with F0 to F1 fibrosis with less accuracy than PS1, but identified patients with F0 to F2 fibrosis with an almost identical level of sensitivity and PPV. CONCLUSIONS: We developed a simple scoring system to determine the severity of fibrosis in patients with genotypes B or C HBV infection who are hepatitis B e antigen positive. Our system differentiated patients with no or mild fibrosis (F0-F1) from those with marked or severe (F2-F4) fibrosis with a high PPV. The high level of specificity for the identification of nonsevere fibrosis (F0-F2) limits the risk of overlooking patients with severe fibrosis (F3-F4).

Response to peginterferon alfa-2a (40KD) in HBeAg-negative CHB: on-treatment kinetics of HBsAg serum levels vary by HBV genotype.

BACKGROUND & AIMS: We investigated whether HBV genotype influences on-treatment HBsAg kinetics and/or the end-of-treatment HBsAg levels associated with long-term virological response in HBeAg-negative chronic hepatitis B patients treated with peginterferon alfa-2a±lamivudine in the Phase III trial. METHODS: All patients (n=230) who participated in long-term follow-up were included according to the availability of HBsAg level measurements. Long-term virological response was defined as HBV DNA ≤ 10,000cp/ml (1786IU/ml) at 5 years post-treatment. Genotype-specific end-of-treatment HBsAg levels associated with long-term virological response (identified by ROC analysis) were assessed in 199 patients with HBsAg measurements available at baseline and end-of-treatment. HBsAg kinetics according to genotype and long-term virological response were investigated in the 117 patients with additional samples available at weeks 12, 24, and 72. RESULTS: Baseline HBsAg levels were significantly higher for A than B, C, and D genotypes (p<0.05). On-treatment HBsAg kinetics varied according to HBV genotype. The difference between responders and non-responders was greatest for genotype A from weeks 12-24; for genotypes B and D from baseline to week 12; there was no significant difference over any timeframe for genotype C. High positive predictive values for long-term virological response could be obtained by applying end-of-treatment genotype-specific cut-offs: 75%, 47%, 71%, and 75% for genotypes A (<400IU/ml), B (<50IU/ml), C (<75IU/ml), and D (<1000IU/ml), respectively. CONCLUSIONS: On-treatment HBsAg kinetics vary between HBV genotypes. Genotype-specific monitoring timeframes and end-of-treatment thresholds could ameliorate response-guided treatment of HBeAg-negative chronic hepatitis B.

Hepatitis B surface antigen levels: association with 5-year response to peginterferon alfa-2a in hepatitis B e-antigen-negative patients.

PURPOSE: To investigate the durability of response to peginterferon alfa-2a up to 5 years post-treatment and factors associated with response in hepatitis B e-antigen (HBeAg)-negative patients. METHODS: HBeAg-negative patients received peginterferon alfa-2a (180 µg/week) ± lamivudine (100 mg/day) for 48 weeks as part of a multicenter, randomized study. The planned 5-year efficacy analysis included patients (n = 230) enrolled in the long-term follow-up study. On-treatment hepatitis B surface antigen (HBsAg) decline kinetics were analyzed retrospectively in a subgroup of patients with HBsAg data available at baseline, weeks 12, 24, and 48 on-treatment, and 6 months post-treatment (n = 120). Receiver operating characteristic analyses identified the on-treatment HBsAg levels associated with response at 1 and 5 years post-treatment. RESULTS: HBV DNA ≤2,000 IU/mL and HBsAg clearance at 5 years post-treatment were achieved by 23 and 12% of patients, respectively. High rates of HBsAg clearance at 5 years post-treatment were achieved by patients with HBV DNA ≤2,000 IU/mL at 1 year post-treatment (28%). Rates of HBV DNA ≤2,000 IU/mL at 1 year post-treatment were 47.2 and 43.4% in patients with ≥10% decline from baseline at weeks 12 and 24, respectively, compared with 16.4% (p = 0.0003) and 13.2% (p < 0.0004) in patients with a <10% decline. Rates of HBsAg clearance at 5 years post-treatment were 22.6 and 22.4% in patients with ≥10% decline at weeks 12 and 24, respectively, compared with 7.5% (p = 0.0161) and 3.8% (p < 0.0001) in patients with <10% decline. CONCLUSIONS: Peginterferon alfa-2a results in increasing rates of HBsAg clearance during post-treatment follow-up in HBeAg-negative patients. On-treatment decline in HBsAg is significantly associated with long-term post-treatment response.

Hepatitis B surface antigen: association with sustained response to peginterferon alfa-2a in hepatitis B e antigen-positive patients.

PURPOSE: Patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, who achieve HBeAg seroconversion 6 months after completing 48 weeks of peginterferon alfa-2a therapy, have an increased chance of clearing hepatitis B surface antigen (HBsAg) during long-term treatment-free follow-up. This analysis aimed to determine whether HBsAg quantification during treatment could be used to identify posttreatment response. METHODS: Patients (n = 399) treated with peginterferon alfa-2a (180 µg/week) alone or in combination with lamivudine (100 mg/day) for 48 weeks during a large, randomized study were included in this retrospective analysis. Receiver-operating characteristic analyses were used to identify baseline and on-treatment HBsAg levels associated with response (HBeAg seroconversion 6 months posttreatment). RESULTS: Baseline HBsAg levels were lower in patients achieving posttreatment response than in nonresponders (3.97 and 4.21 IU/mL, respectively, p = 0.039). Two baseline HBsAg cutoff levels (5,000 and 50,000 IU/mL) provided a positive predictive value of 42% and a negative predictive value of 77%. HBsAg decline was significantly greater during and posttreatment in responders than in nonresponders (p < 0.0001). HBeAg seroconversion rates 6 months posttreatment were significantly higher in patients with HBsAg < 1,500 IU/mL at weeks 12 and 24 (56.7 and 54.4%, respectively) versus patients with HBsAg 1,500-20,000 IU/mL (32.3 and 26.1%, respectively) or HBsAg < 20,000 IU/mL (16.3 and 15.4%, respectively) (all p < 0.0001 and <0.0001). CONCLUSIONS: HBsAg levels at baseline strongly associated with posttreatment response were not identified. Low HBsAg levels during peginterferon alfa-2a therapy were associated with high rates of posttreatment response. On-treatment HBsAg quantification may, therefore, help guide patient management in the future.