The inaugural Asian Oncology Summit (AOS) – 2009 was held at Suntec Singapore International Convention & Exhibition Centre, Singapore. AOS major success is to have a partnership with South East Asian Medical Oncology Forum (SEAMOF) to encourage collaboration among oncologists in Southeast Asia. The Summit encompassed a series of plenary lectures covering a variety of haematological and solid cancers. There were additional six parallel suites dedicated to haemato-oncology, head and neck, gastrointestinal, breast, lung, and gynaecological cancer. The summit described the latest clinical needs for oncologists in Asia and offered an opportunity for the exchange ideas and thoughts that will help inform clinical practice. Notable international experts includes Prof Harald zur Hausen (Nobel Laureate) had discussed topics of pertinent clinical relevance.
During AOS, experts in oncology shared their experience how to combat cancer incidences and treatment strategy in various cancer types. It was estimated that 58.8 million people died globally from cancer in 2004 (WHO 2008). In South East Asia, it is estimated that in 2008 there were 1,589,000 incident cases of cancer (758,000 in men and 831,000 in women) and 1,072,000 deaths from cancer (approx 557,000 in men and 515,000 in women). In men, the commonest cancer was lung cancer, followed by oral cancer and in women, cervix and breast cancer were the commonest incident.
A panel of speakers had delivered speech on currently available targeted therapy in combination of conventional treatment, and stratified drug therapy with respect to cancer genetics. Targeted therapy has been encouraging the oncologists in the treatment of haematological and solid tumors. Small molecules (tyrosine kinase inhibitors; TKIs) as well as biologics (monoclonal antibodies; mAb) have been evaluated in different tumors in combination with chemotherapy (CT) and/or radiotherapy (RT). TKIs (gefitinib, imatinib, sorafinib, sunitinib) and mAb (cetuximab, trastuzumab, bevacizumab, nimotuzumab) described therapeutic efficacy in binding to their respective targets and hence improved in response rate to the treatment. Some of the clinical trials with targeted therapy have shown an increase in progression-free survival (PFS) as well as overall survival (OS) rate in cancers such as breast, head and neck etc. However, some of the anti-EGFR agents have been associated with severe toxicity in cancer patients.
During the recent summit, nimotuzumab (TheraCIM) had drawn attention by the oncologists and scientists from different parts of the world for its “affinity-optimizedTM” properties towards EGF receptor. Dr Rikrik Ilyas, director, Innogene-Kalbiotech, Singapore had described the development and therapeutic efficacy of nimotuzumab in treating tumors with high EGFR expression. Nimotuzumab is a humanised monoclonal anti-EGFR antibody with reduced toxicity and immunogenicity, and has been approved for the treatment of nasopharyngeal carcinoma (NPC), SCCHN and glioma. The combination of nimotuzumab and RT has significantly increased overall response rate in patients with NPC and other advanced stage head and neck cancers.
During a satellite symposium organised at AOS by Innogene-Kalbiotech, Prof Mark Vincent from University of Western Ontario, Canada explained that “nimotuzumab efficacy in the treatment of EGFR over-expressed tumors is similar to other anti-EGFR agents, cetuximab and panitumumab. Regarding toxicity, nimotuzumab discriminates cells with respect to EGFR expression by binding preferentially to tumor cells over-expressing EGFR, whereas cetuximab and panitumumab bind to all tissues expressing EGFR. The attachment of nimotuzumab to EGFR required bivalent binding, which occurs more readily when EGFR density is elevated. In contrast, when EGFR density is low, such as in healthy tissue, cetuximab and panitumumab continued to interact strongly with EGFR through monovalent binding, while nimotuzumab monovalent binding was transient thus sparing healthy tissues and avoiding the associated severe toxicities. An “affinity-optimizedTM” property of nimotuzumab has shown superior safety profile while exhibiting similar therapeutic efficacy compared to other anti-EGFR mAbs. Severe hypomagnesemia and skin rash is common with the treatment of cetuximab and panitumamab. High rate of severe radiation dermatitis during radiation therapy with concurrent cetuximab in head and neck cancer has been reported”.
A positive relation between the presence and severity of treatment-related rash and survival has been consistently observed with all ant-EGFR agents approved for clinical use. These findings suggest that rash may be a useful surrogate marker of successful EGFR inhibition and clinical benefit and therefore of possible use in identifying patients most likely to benefit from therapy, as well as to guide dose adjustments. However, absence of skin rash with the treatment of nimotuzumab makes it a unique therapeutic agent among the class of anti-EGFR mAb.
In a statement given by Prof Randolph HJ, UCLA “the rash is not only unsightly but is painful and can lead to serious infections. I have had patients require urgent surgical drainage of abscesses related to EGFR rashes. EGFR inhibitor with anticancer activity, but without skin toxicity, would be a great advance for patients”
Nimotuzumab has therefore emerged as a promising therapeutic option for patients with advanced epithelial tumours.
The second Asian Oncology Summit being planned to host at Bali, Indonesia (April 9-11, 2010).