In the treatment of advanced non-small cell lung cancer (NSCLC), small-molecule tyrosine kinase inhibitors (TKIs) of the epidermal growth factor (EGFR) represent a breakthrough for targeted therapies. These drugs, erlotinib (Tarceva, OSI pharmaceuticals) and gefitinib (Iressa, AstraZeneca), are generally well-tolerated, and provide an alternative to chemotherapy in second line treatment. Yet, these drugs show survival benefit only for a subset of patients, and further, there is emerging evidence that these drugs may adversely affect a considerable percentage of patients in comparison with standard of care treatment.

The difficulties in using targeted therapies in an unselected population become more pronounced if one considers the pharmaco-economic impact of these expensive therapies. For example, the NICE board (an advisory committee to the National Health Service in the United Kingdom) is not recommending the use of targeted therapies based on cost-risk analysis. Ultimately, the success of targeted therapies will hinge on the development of suitable patient selection tools. To cite a recent editorial: ‘The ability to predict treatment response and clinical (survival) outcomes is one of the 'holy grails' of cancer biomarker development...’ (M.-S. Tsao, G. Liu, F. Shepherd, JNCI 99(11), 826(2007)).

VeriStrat™ is a simple blood test that provides additional information to oncologists treating non-small cell lung carcinoma (NSCLC) during their decision making process. Through extensive retrospective trials, and currently in prospective trials, VeriStrat has been shown to be clinically informative with when treating with erlotinib and gefitinib.

VeriStrat uses small amounts (10 microliters) of serum or plasma. VeriStrat assigns a label (VeriStrat Good or VeriStrat Poor) to each patient's sample. It has been shown in multiple blinded validation sample sets that VeriStrat Good patients exhibit significantly longer overall survival than VeriStrat poor patients (see Figure 1 below).

VeriStrat has been extensively validated and the results are available through a publication in the Journal of the National Cancer Institute (Taguchi, Solomon et al, JNCI 99(11), 838(2007))Results have also been presented in invited lectures at American Society of Clinical Oncologists annual meetings in 2006 and 2007, at the targeted drug development meeting in Santa Monica 2006, at the Biotherapy Development Agency meeting in Innsbruck (Austria) 2007, and will be presented to the NCI annual lung cancer SPORE meeting in Baltimore.

Figure 1: Applying Biodesix's pre-treatment serum test leads to a well-defined separation of survival curves even for the subgroup of patients that have a positive smoking history, a result that is not derivable with any other diagnostic. The green curve (Good) describes the survival fraction of patients that were identified by the Company's test as deriving benefit from gefitinib, the red curve (Bad) shows the survival fraction of patients deriving no benefit from treatment with gefitinib.

Biodesix currently plans to make VeriStrat available to lung cancer patients through their oncologists by the fourth quarter of 2008.