On to the curious for Thrombogenics

Oncology is hot so it makes perfect sense for the struggling Belgian group Thrombogenics to spin out its share of TB-403, a largely forgotten cancer asset, into a brand new joint venture, however speculative this move actually is.

Today’s setting up of Oncurious should also remind investors of the attempted resurrection of another depressed European biotech, Sweden’s BioInvent. That said, the convoluted ownership status of TB-403 could raise questions over its economic viability, and the science behind its use in brain cancer is far from clear.

Nevertheless, Thrombogenics cites a 2013 paper published in Cell, reporting the expression of the placental growth factor (PGF) receptor neuropilin 1 in medulloblastoma – a paediatric brain tumour type that is the chosen new indication for TB-403. The project is a humanised MAb against PGF.

Thrombogenics stock was up 6% in afternoon trading today, while BioInvent rose 8%. TB-403 had been licensed by these two companies on a 60/40 co-promotion basis from the Belgian life sciences research institute VIB in return for a royalty, but its development for glioblastoma and liver cancer stalled back in 2012.

Interestingly, however, BioInvent has no equity in the new Oncurious venture, implying that it simply retains its 40% co-development rights. This is despite the Swedish group turning to oncology after suffering a succession of setbacks three years ago (BioInvent scores unpleasant biotech triple, July 11, 2012).

Instead, Oncurious is majority owned by Thrombogenics, with a stake of over 90%. VIB holds the remainder, having swapped its royalty interest in oncology indications for an equity stake, VIB’s managing director, Johan Cardoen, told EP Vantage. A phase I/II study is to start enrolling medulloblastoma patients at the end of this year.

BioInvent did not respond to a request to comment on why it did not take an equity interest in Oncurious. Its current lead project, BI-505, is in a phase II multiple myeloma study.

Of course, Thrombogenics itself has been through a rough period, with its eye drug Jetrea missing US sales expectations spectacularly owing to safety concerns and physician reluctance to adopt it.

The group last year put itself up for sale, but failed to find a buyer and saw its chief financial officer resign. It is clearly not giving up on eye diseases, and retains an exclusive licence to TB-403’s ophthalmic indications such as diabetic retinopathy and macular degeneration.

No Roche endorsement

In oncology TB-403 had already been licensed to and then ditched by Roche. The Swiss group had discontinued a phase I liver cancer study owing to poor recruitment, and began a 100-patient phase I/II glioblastoma trial in combination with Avastin.

This too was terminated, with no data published, after its phase I portion recruited 22 patients, and Roche handed the asset back in 2012. Unusually, the Swiss firm did not retain any interest in TB-403, for instance by way of a small royalty payaway, VIB and Thrombogenics told EP Vantage.

Even so, the three-way rights to TB-403 could deter future licensees. Then there is the science: the involvement of PGF in oncology is complex, and Roche giving up on glioblastoma is not a great sign, though the reason cited at the time was prioritisation of resources.

PGF is a member of the VEGF family, hence the logic behind its earlier combination with Avastin. There had been suggestions that tumour cells needed to be VEGF1 receptor-positive to respond to PGF targeting, but biomarker involvement is still unclear.

Still, Thrombogenics has little to lose in giving oncology a crack. After all speculative cancer investments are attracting significant US funding in the current market, and the prospect of a paediatric indication, implying a possible accelerated development pathway, could prove popular with investors.

To contact the writer of this story email Jacob Plieth in London at jacobp@epvantage.com or follow @JacobPlieth on Twitter

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