Tuesday, September 27, 2011

Silence Therapeutics Signs Lung Delivery Deal with Mystery Partner

As Tekmira is struggling to regain possession over its delivery technology from mighty Alnylam, it is foremost Silence Therapeutics' business development that is benefitting from having one of the most advanced, clinically tested, and commercially uncontested systemic delivery technologies in RNAi Therapeutics. Less than a month after closing a deal with Dutch company InteRNA under which Silence’s AtuPLEX lipoplex delivery technology will be evaluated for the delivery of microRNA cancer therapeutics, the company has just announced another delivery collaboration, this time for the related DACC delivery system. Like AtuPLEX, DACC targets vascular endothelial cells, but unlike AtuPLEX it does so with a high preference for the vascular endothelia of the lung.

Curiously, the identity of the partner was not disclosed, although it was mentioned that it was a ‘Top 10 Pharma Company’. 'Top 10 Pharma Company'....didn't Takeda just become Number 10 with the acquisition of Nycomed? Moreover, the Nycomed acquisition included a fresh COPD drug, a pulmonary disease with an inflammatory component for which the DACC delivery system could very well be useful.

You can imagine that Takeda is a bit hesitant to talk about RNAi Therapeutics, maybe having overpaid a bit for what Alnylam really sold them, but with their significant investment in RNAi already it has every incentive to get things moving while Tekmira and Alnylam are fighting it out. Maybe following this rationale, Takeda and South Korean company Samyang announced earlier this year a somewhat surprising delivery collaboration.

The press release also noted that it is the partner that will provide the RNAi triggers. This pretty much excludes Silence’s existing Big Pharma partners AstraZeneca and Dainippon Sumitomo, the latter of which is not a Top 10 Pharma anyway. On the other hand, Takeda licensed RNAi triggers from Alnylam only for the metabolic and oncology fields, something that would probably add to the apparent sensitivities. I highly doubt that Takeda will hand over another $50M to Alnylam for pulmonary.

Of course, it is always possible that RNAi Therapeutics has gone so much out of fashion that Big Pharma companies are embarrassed to be publicly associated with it. Not only that, their investors shun the word ‘Research’ like the plague.

More seriously, the data that Silence reported for the DACC system has been quite impressive. Working on a model for acute lung injury, it has demonstrated potent and persistent gene knockdown in the pulmonary vascular endothelium following a single intravenous administration. While less is known about the clinical safety profile of DACC, it can be considered somewhat de-risked by the fact that its chemistry seems to be very similar to the clinically proven AtuPLEX system (see the highly encouraging safety profile of their phase I Atu027 clinical candidate so far).

2 comments:

Anonymous said...

Who owns MiR-21? That would appear a valid pulmonary fibrosis microrna target.

Dirk Haussecker said...

Lung fibrosis, of course, is a big issue and largely untapped market. However, with miR-21 and fibrosis you would probably want to inhibit it in fibroblasts, not endothelial cells where the DACC system seems to go. There are miRNA-inhibitors that would benefit from a delivery system like DACC. However, most microRNA inhibitions still attempt the 'naked' administration of phosphorothioate antisense oligos, almost regardless of cell/tissue type.

Lung fibrosis and DACC... should be possible in theory, but probably with different target and mechanism of action.

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