Safety and preliminary activity results of the GATTO study, a phase Ib study combining the anti-TA-MUC1 antibody gatipotuzumab with the anti-EGFR tomuzotuximab in patients with refractory solid tumors.

BACKGROUND: The phase I GATTO study (NCT03360734) explored the feasibility, tolerability and preliminary activity of combining gatipotuzumab, a novel humanized monoclonal antibody binding to the tumor-associated epitope of mucin 1 (TA-MUC1) and an anti-epidermal growth factor receptor (anti-EGFR) antibody in refractory solid tumors. PATIENTS AND METHODS: Initially the study enrolled primary phase (PP) patients with EGFR-positive metastatic solid tumors, for whom no standard treatment was available. Patients received gatipotuzumab administered at 1400 mg every 2 weeks, 6 weeks after the start of the glyco-optimized anti-EGFR antibody tomuzotuximab at 1200 mg every 2 weeks. As this regimen was proven safe, enrollment continued in an expansion phase (EP) of patients with refractory metastatic colorectal cancer, non-small-cell lung cancer, head and neck cancer and breast cancer. Tomuzotuximab and gatipotuzumab were given at the same doses and gatipotuzumab treatment started 1 week after the first dose of the anti-EGFR antibody. Additionally, investigators could use a commercial anti-EGFR antibody in place of tomuzotuximab. RESULTS: A total of 52 patients were enrolled, 20 in the PP and 32 in the EP. The combined treatment was well tolerated and no dose-limiting toxicity was observed in the whole study, nor related serious adverse event or death. Preliminary activity of the combination was observed, with one and four RECIST partial responses in the PP and EP, all in colorectal cancer patients. The trial was accompanied by a comprehensive translational research program for identification of biomarkers, including soluble TA-MUC1 (sTA-MUC1) in serum. In the EP, patients with baseline sTA-MUC1 levels above the median appeared to have improved progression-free survival and overall survival. CONCLUSIONS: Combination of a TA-MUC1-targeting antibody and an EGFR-targeting antibody is safe and feasible. Interesting antitumor activity was observed in heavily pretreated patients. Future studies should test this combination together with chemotherapy and explore the potential of sTA-MUC1 as a companion biomarker for further development of the combination.

A randomized phase II study comparing the efficacy and safety of the glyco-optimized anti-EGFR antibody tomuzotuximab against cetuximab in patients with recurrent and/or metastatic squamous cell cancer of the head and neck - the RESGEX study.

BACKGROUND: The aim of the RESGEX study was to compare the efficacy and safety of the anti-epidermal growth factor receptor (anti-EGFR) antibody tomuzotuximab against cetuximab both in combination with chemotherapy in patients with recurrent and/or metastatic squamous cell cancer of the head and neck in the first-line treatment. PATIENTS AND METHODS: In this phase II trial 240 patients were equally randomized for six cycles to receive either tomuzotuximab (initial dose 990 mg then 720 mg) weekly and cisplatin 100 mg/m2 and fluorouracil (5-FU; 1000 mg/m2/day, days 1-4) every 3 weeks or cetuximab (400 mg/m2 subsequent 250 mg/m2) weekly with the same chemotherapeutic backbone followed by antibody maintenance treatment. The primary endpoint was progression-free survival. RESULTS: Median progression-free survival was 6.5 months [95% confidence interval (CI) 5.9-7.9 months] in the tomuzotuximab group and 6.2 months (95% CI 5.8-7.3 months) in the cetuximab group (P = 0.86). The median overall survival (OS) estimate was 11.6 months (95% CI 9.5-17.2 months) in the tomuzotuximab group and 13.8 months (95% CI 12.3-16.4 months) in the cetuximab group (P = 0.96). In an exploratory analysis a small subgroup of p16-positive patients had a significantly longer OS compared with p16-negative patients (hazard ratio 1.860, 95% CI 1.09-3.16, P = 0.02). CONCLUSIONS: The glyco-engineered antibody tomuzotuximab failed to demonstrate improved efficacy with a chemotherapeutic backbone in the first-line treatment of recurrent or metastatic head and neck squamous cell carcinoma. It remains a so far unanswered question whether such antibody would partner better with different drugs such as checkpoint inhibitors.

Cetuximab, fluorouracil and cisplatin with or without docetaxel for patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck (CeFCiD): an open-label phase II randomised trial (AIO/IAG-KHT trial 1108).

BACKGROUND: The combination of cisplatin, 5-fluorouracil (5-FU) and cetuximab (PFC) is the reference first-line treatment for recurrent/metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN). We analysed whether treatment intensification by the addition of docetaxel to PFC improved efficacy in R/M SCCHN. METHODS: A total of 180 patients with R/M SCCHN (1:1) were assigned to receive either cisplatin (40 mg/m2), docetaxel (40 mg/m2) and 5-FU (2000 mg/m2) at days 1 and 8 and cetuximab (400/250 mg/m2) at days 1, 8 and 15 (DPFC) or standard cisplatin (100 mg/m2) at day 1, 5-FU (1000 mg/m2) at days 1-4 and cetuximab (400/250 mg/m2) at days 1, 8 and 15 (PFC). Chemotherapy was repeated every 21 days and continued for a maximum of 6 cycles in absence of disease progression or limiting toxicity, followed by cetuximab maintenance (500 mg/m2 every 2 weeks). The primary end-point was progression-free survival (PFS). RESULTS: A preplanned interim analysis for toxicity after 20 patients/arm revealed excessive grade 3 and 4 gastrointestinal (65%) and infectious toxicities (35%) in arm A, which led to dose reduction of cisplatin to 30 mg/m2 and 5-FU to 1000 mg/m2 for subsequent patients. With a median follow-up of 2 years, grade 4 toxicities were 21.3% vs. 30.8% for DPFC and PFC, respectively. More treatment-related deaths occurred with DPFC vs. PFC, with 11.2% and 6.6%, respectively. For DPFC and PFC, the median PFS was 6.3 vs. 6.4 months (hazard ratio [HR] = 0.97, p = 0.87), the median overall survival was 8.9 vs. 10.6 months (HR = 1.29 p = 0.1) and response rates were 38.2% vs. 31.9% (p = 0.9), respectively. CONCLUSIONS: DPFC failed to improve efficacy in R/M SCCHN. On the contrary, a high toxicity and mortality rate was detected in both arms, which underscores the vulnerability of patients with R/M SCCHN, and research on the need for further optimisation of the front-line chemotherapy backbone is ongoing.

First-in-man dose escalation and pharmacokinetic study of CAP7.1, a novel prodrug of etoposide, in adults with refractory solid tumours.

AIM: An open-label, phase I dose-escalation trial was performed in adult patients with various solid cancers to identify the maximum tolerated dose (MTD), to assess the safety, pharmacokinetic profile and anti-tumour activity of the new prodrug CAP7.1. The prodrug is converted to its active moiety etoposide via carboxylesterases in selective cells leading to a better tolerability and higher efficacy in therapeutic resistance cells and children with refractory neuroblastoma. PATIENTS AND METHODS: Eligible adult patients with advanced, refractory, solid malignancies received CAP7.1 as intravenous infusion on 5 consecutive days. Doses were escalated in four cohorts consisting of three to six patients, with a starting dose of 45 mg/m2/day. Treatment cycles were repeated in 21-day intervals in the absence of disease progression and prohibitive toxicity. The safety, pharmacokinetics and efficacy were evaluated, and the MTD and dose-limiting toxicity (DLT) were determined. RESULTS: Nineteen patients were assigned to four CAP7.1 dose cohorts (45, 90, 150 and 200 mg/m2/day). CAP7.1 was well tolerated. Haematotoxicity was observed at the two highest dose levels including three DLTs (two febrile neutropenia and one sepsis) only and were reversible with adequate therapy. No organ toxicity was observed. Non-haematological toxicities (mild-moderate) consist mainly of nausea, fatigue, vomiting, pyrexia and alopecia. One partial response and 11 stable diseases were observed as supporting signs of efficacy. CONCLUSION: MTD of CAP7.1 was reached at the dose of 200 mg/m2. A favourable safety profile and initial anti-tumour efficacy of CAP7.1 in therapeutic refractory tumours warrant further evaluation in clinical studies.

Contribution of human papilloma virus to the incidence of squamous cell carcinoma of the head and neck in a European population with high smoking prevalence.

BACKGROUND: Increases in incidence of oropharyngeal squamous cell carcinoma (OPSCC) in countries with falling tobacco use have been attributed to a growing role of human papilloma virus (HPV) in the carcinogenesis. Trends of HPV prevalence in populations with persistently high portions of smokers are poorly characterised. PATIENTS AND METHODS: Registry data from East Germany were used to determine incidence trends between 1998 and 2011. Data from patients treated at the Charité University Medicine Berlin between 2004 and 2013 (cohort 1, N=436) were used for estimation of trends in HPV prevalence, smoking and survival. HPV prevalence was prospectively confirmed in cohort 2 (N=213) comprising all primary HNSCC cases at the Charité in 2013. RESULTS: Between 1998 and 2011 incidence of both OPSCC and non-OPSCC increased. An increase in HPV prevalence (% of HPV+ cases in 2004-2006 versus 2012-2013: 27% versus 59%, P=0.0004) accompanied by a moderate decrease in the portion of current smokers was observed in OPSCC but not in non-OPSCC. The change in disease epidemiology in OPSCC was associated with significant improvement in overall survival. Increased HPV prevalence in OPSCC (48%) compared to non-OPSCC (11%) was confirmed in cohort 2. CONCLUSIONS: Despite clear differences to the United States in terms of tobacco use, the increase in OPSCC incidence in a European population was also mainly attributed to HPV, and the HPV status significantly affected prognosis. For clinical trial design it is important to consider the large group of smokers within HPV-induced OPSCC.