Daiichi ditches lung cancer study as drug fails efficacy test

The future for Daiichi Sankyo’s midstage candidate patritumab in non-small cell lung cancer (NSCLC) drug hangs in the balance after the Tokyo-based firm said it would stop a second trial for the disease as its treatment failed to work as predicted.

The Japanese drugmaker had been undertaking a two-part Phase III test of its candidate patritumab--but this week has said it will now not proceed into the second part.

This comes after a recommendation from an independent data monitoring committee (DMC) that found the first part of the study did not work as well as the company said it should before the trial, and therefore could not go on to the Part B of the study. There were, however, no safety concerns identified by the DMC.

The HER3-Lung study was looking at the HER3-inhibitor patritumab, in combination with Roche’s ($RHHBY) marketed NSCLC drug Tarceva (erlotinib), in patients with locally advanced or metastatic non-small cell lung cancer not selected for EGFR mutation but stratified by tumor expression of heregulin.

There are already a number of NSCLC treatments on the market, with many targeting certain sub-populations of patients with genetic biomarkers, such as EGFR mutations (Tarceva), or ALK, as seen with Pfizer’s ($PFE) Xalkori (crizotinib) and most recently PD-L1, in the form of Merck’s ($MRK) Keytruda (pembrolizumab).

There are currently no marketed HER3-inhibitors for NSCLC--but it is seen as an unmet medical need as human epidermal growth factor receptor HER3 is aberrantly overexpressed and correlates with poor prognosis in the disease.  

Antoine Yver, executive VP and global head of oncology research and development at Daiichi, said: "We are disappointed that this study did not confirm the hypothesis that effective HER3 inhibition in combination with erlotinib would provide clinically relevant tumor growth control in subjects with advanced non-small cell lung cancer.

“Nevertheless, rigorously designed experiments such as Part A of this study in this particular case is at the core of what we do: Transform innovative science into value for patients suffering from cancer. The very nature of experiments is to resolve uncertainty and some are bound to not confirm the hypothesis tested."

Daiichi said in a statement that it has accepted the DMC recommendation and is providing information regarding study discontinuation to health authorities and clinical investigators participating in the HER3-Lung study. Data from this study will be presented at an upcoming scientific meeting.

Daiichi stressed that other tests for the drug in head and neck cancers were not affected by its NSCLC failure, and were ongoing.

The company will also continue to examine the data to “better understand the results and determine next steps for the development of patritumab in non-small cell lung cancer.”

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