Non-Small-Cell Lung Cancer Leading cause of cancer-related mortality in the US Current Therapies: –“ Despite great efforts, only minor gains” Traynor et al –Combination of Chemo/Surgery/Radiotherapy: Platinum Doublets favored, in combo with other chemo reagent. Future Therapies: 166 ongoing clinical trials –EGFR over expressed in 40 to 80 % of cancers

Peptide Vaccine Phase I Study of EGFRvIII Peptide Vaccine With Sargramostim (GM-CSF) Versus Keyhole Limpet Hemocyanin as Adjuvant in Patients With EGFRvIII- Expressing Cancer Epidermal Growth Factor Receptor VIII Peptide Vaccination Is Efficacious against Established Intracerebral Tumors Heimberger et al. 2003

Vaccine Based Immunotherapy to L523S –Phase I: Safety and Immunogenicity of Recombinant DNA and Adenovirus Expressing L523S Protein in Early Stage Non-Small Cell Lung Cancer The purpose of this trial is to examine the safety and immunogenicity of a therapeutic vaccine regimen with recombinant DNA and adenovirus expressing L523S protein in patients with early stage non-small cell lung cancer. The vaccine regimen will consist of two fixed doses of recombinant DNA (pVAX/L523S) followed by two doses of recombinant adenovirus (Ad/L523S). The trial will evaluate the dose escalation of Ad/L523S through three cohorts of patients.

EGFR Schematic Sordella et al. 2004

Gefitinib: Targeting the proliferative signals in cancer cells - -> EGFR –1) In-Vitro Proof of Concept ZD1839 Synthesized/Screened –2) Animal Models –Mouse Xenografts: Success Not Dependant on Level of Expression of EGFR –3) Initial Clinical Trials: Limited Tox Response in only 10-19% of chemo-refractory advanced NSCL cancers R Bailey et al > EGFR Expression not an effective predictor of response to gefitinib –4) Molecular explanation???

Factors that favor Gefitinib sensitivity: –Woman –Non-Smoker –Japenese –Adenocarcinoma »Paez et al. 2004

A highly significant effect in sensitive patients

So What are the Mutations? Extract DNA Amplify Gene of Interest (28 exons) PCR Sequence (Sense + Antisense)

What do these mutations tell us? 1) Hypothesis: Improved stability for binding of ATP and Gefitinib –Modified ATP binding pocket. 2) Hypothesis: Mutation plays a key role in the development of this cancer. – Somatic – Heterozygous ---> Dominance – Sequenced 95 primary tumors, 108 cancer-derived cell lines. No EGFR mutants

What does this all mean? Marker for the success of gefitinib? –Is this a good clinical test? –If there is no toxicity, can you add drug on top of standard therapy despite low probability of success? Why the insensitivity with W.T. gefitinib? –1) Kinetics: Bioavailability poor, (K D too high) Find a better way to knock out Kinase –2) The Mutant Kinase is more important to the cancer, than the wild type. Overexpression does not mean functionality is key. In-vitro models have to be interpreted carefully.

Science, August 20th 2004.