Oncoethix SA raised CHF18 million (US$18.7 million) in a Series B round to move its bromodomain and extra-terminal (BET) inhibitor OTX015 into Phase II proof-of-concept studies in hematological malignancies.

The Lausanne, Switzerland-based firm in-licensed the compound from Mitsubishi Tanabe Pharma Corp., of Osaka, Japan, last year, after it had completed Phase I trials in healthy volunteers. Earlier this year, Oncoethix began a Phase I dose-finding study in patients with acute leukemia and other hematological malignancies.

The company has yet to release any data from the study, but presumably the results gathered to date were sufficiently convincing for its investors to pony up the new funds.

The company was unwilling to provide any comment on the present investment round, other than the information contained in a news release.

SV Life Sciences (SVLS) led the round, and Paris-based Edmond de Rothschild Investment Partners also joined as a new investor, while existing investors Index Ventures and Endeavour Vision also participated. The company has now secured CHF28 million in venture capital funding since its formation in 2007.

Oncoethix is one of several firms targeting the BET bromodomain proteins 2/3/4, which are considered 'readers' of epigenetic marks, namely acetylated-lysine residues found on histone-associated proteins. One of the main targets of BET inhibitor drug development efforts is the transcription factor c-Myc, which is constitutively overexpressed in many cancers, but which has been considered an undruggable target up to now.

BET inhibition downregulates c-Myc expression, which leads to reductions in the expression of Myc-dependent genes. In experimental models of several Myc-dependent hematologic malignancies, according to Oncoethix, BET inhibition led to "a potent antiproliferative effect associated with cell cycle arrest and cellular senescence."

James Bradner and Constantine S. Mitsiades at Dana Farber Cancer Institute in Boston, and colleagues, provided the underlying experimental proof of principle, in a paper, titled "BET bromodomain inhibition as a therapeutic strategy to target c-Myc," which appeared in the Sept. 16, 2011, issue of Cell.

London-based Glaxosmithkline plc also is developing a BET inhibitor, GSK525762, which is undergoing a Phase I study in patients with NUT midline carcinoma and other cancers.

Outside the oncology field, Calgary, Alberta-based Resverlogix Corp. recently reported that its first-in-class BET inhibitor RVX-208 failed to hit the primary endpoint of a Phase IIb trial in high-risk cardiovascular patients with low levels of high-density lipoprotein. The drug, which is intended to boost levels of ApoA-I protein, failed to reduce atherosclerotic plaque by the desired amount.