Development of oligopeptidic prodrugs of anticancer anthracyclines

Doctorat en sciences - UCL, 200

Docetaxel and cisplatin as induction chemotherapy in patients with pathologically-proven stage IIIA N2 non-small cell lung cancer: a phase II study of the European organization for research and treatment of cancer (EORTC 08984)

The objective of this phase II study was to document activity and toxicity of docetaxel and cisplatin as induction chemotherapy in patients with stage IIIA N2 non-small cell lung cancer (NSCLC) before definitive local treatment. Forty-six chemotherapy-naı¨ve patients (median age 60 years) were included. Treatment consisted of 3 cycles of docetaxel (85 mg/m2 on day 1), followed by cisplatin (40 mg/m2/day on days 1 and 2) every 21 days. Grade 3–4 leukopenia and neutropenia occurred in 45.7% and 65.2% of the patients, respectively. Among 8 cases of febrile neutropenia (17.4%), one (2.2%) resulted in early death. Common grade 3–4 non-haematological toxicities were nausea (17.4%) and vomiting (13%). Eighty-five percent of the patients received three courses; six stopped prematurely due to toxicity, one due to protocol violation. Response rate was the primary endpoint of this study. Considering eligible patients (n = 40), 18 responses (1 complete and 17 partial responses) were observed (response rate 45%; 95% Confidence interval (CI): 29.3%–61.5%). In stage IIIA-N2 NSCLC patients, docetaxel-cisplatin could be administered and demonstrated manageable toxicity with modest efficacy

Extracellularly tumor-activated prodrugs for the selective chemotherapy of cancer: application to doxorubicin and preliminary in vitro and in vivo studies.

Oligopeptidic derivatives of anthracyclines unable to penetrate cells were prepared and screened for their stability in human blood and their reactivation by peptidases secreted by cancer cells. N-beta-alanyl-L-leucyl-L-alanyl-L-leucyl-doxorubicin was selected as a new candidate prodrug. The NH2-terminal beta-alanine allows a very good blood stability. A two-step activation by peptidases found in conditioned media of cancer cells ultimately yields N-L-leucyl-doxorubicin. In vitro, when MCF-7/6 cancer cells are exposed to the prodrug, they accumulate about 14 times more doxorubicin than MRC-5 normal fibroblasts, whereas when exposed to doxorubicin the uptake is slightly higher in fibroblasts than in MCF-7/6 cells. This increased specificity of the prodrug over doxorubicin was confirmed in cytotoxicity assays using the same cell types. In vivo, the prodrug proved about nine times less toxic than doxorubicin in the normal mouse and also much more efficient in two different experimental chemotherapy models of human breast tumors

Glyco-engineered anti-EGFR mAb elicits ADCC by NK cells from colorectal cancer patients irrespective of chemotherapy

BACKGROUND: The epidermal growth factor receptor (EGFR) is overexpressed in colorectal cancer (CRC), and is correlated with poor prognosis, making it an attractive target for monoclonal antibody (mAb) therapy. A component of the therapeutic efficacy of IgG1 mAbs is their stimulation of antibody-dependent cellular cytotoxicity (ADCC) by natural killer (NK) cells bearing the CD16 receptor. As NK cells are functionally impaired in cancer patients and may be further compromised upon chemotherapy, it is crucial to assess whether immunotherapeutic strategies aimed at further enhancing ADCC are viable. METHODS: CRC patients before, during and after chemotherapy were immunophenotyped by flow cytometry for major white blood cell populations. ADCC-independent NK cell functionality was assessed in cytotoxicity assays against K562 cells. ADCC-dependent killing of EGFR(+) A431 cancer cells by NK cells was measured with a degranulation assay where ADCC was induced by GA201, an anti-EGFR mAb glyco-engineered to enhance ADCC. RESULTS: Here, we confirm the observation that NK cells in cancer patients are dysfunctional. However, GA201 was able to induce robust NK cell-dependent cytotoxicity in CRC patient NK cells, effectively overcoming their impairment. CONCLUSIONS: These findings support the evaluation of the therapeutic potential of GA201 in combination with chemotherapy in CRC patients

An exploratory, open-label, randomized, multicenter study to investigate the pharmacodynamics of a glycoengineered antibody (imgatuzumab) and cetuximab in patients with operable head and neck squamous cell carcinoma

Background: In addition to inhibiting epidermal growth factor receptor (EGFR) signaling, anti-EGFR antibodies of the IgG1 subtype can induce a complementary therapeutic effect through the induction of antibody-dependent cell-mediated cytotoxicity (ADCC). Glycoengineering of therapeutic antibodies increases the affinity for the Fc-gamma receptor, thereby enhancing ADCC.Patients and methods: We investigated the changes in immune effector cells and EGFR pathway biomarkers in 44 patients with operable, advanced stage head and neck squamous cell carcinoma treated with two pre-operative doses of either glycoengineered imgatuzumab (GA201; 700 or 1400 mg) or cetuximab (standard dosing) in a neoadjuvant setting with paired pre- and post-treatment tumor biopsies.Results: Significant anti-tumor activity was observed with both antibodies after just two infusions. Metabolic responses were seen in 23 (59.0%) patients overall. One imgatuzumab-treated patient (700 mg) achieved a pathological complete response. An immediate and sustained decrease in peripheral natural killer (NK) cells was consistently observed with the first imgatuzumab infusion but not with cetuximab. The functionality of the remaining peripheral NK cells was maintained. Similarly, a pronounced increase in circulating cytokines was seen following the first infusion of imgatuzumab but not cetuximab. Overall, tumor-infiltrating CD3+ cell counts increased following treatment with both antibodies. A significant increase from baseline in CD3+/perforin+ cytotoxic T-cells occurred only in the 700 mg imgatuzumab group (median 95% increase, p &lt; 0.05). The most prominent decrease of EGFR-expressing cells was recorded after treatment with imgatuzumab (700 mg: –34.6%; 1400 mg: –41.8%). The post-treatment inflammatory tumor microenvironment was strongly related to baseline tumor-infiltrating immune cell density, and baseline levels of EGFR and pERK in tumor cells most strongly predicted therapeutic response.Conclusions: These pharmacodynamic observations and relationship with efficacy are consistent with the proposed mode of action of imgatuzumab combining efficient EGFR pathway inhibition with ADCC-related immune anti-tumor effects.Clinical trial registration number: NCT01046266 (ClinicalTrials.gov).</p