Oncothyreon’s promise grows distant

It is just as well that in Merck KGaA Oncothyreon has a senior partner willing to fund its lead asset against the odds. Tecemotide, the potential cancer vaccine formerly known as Stimuvax, failed another clinical trial yesterday.

While Merck continues running a phase III tecemotide study that will read out in 2018, it is worth asking where this leaves Oncothyreon. A recent acquisition has given Oncothyreon a cutting-edge technology, but the company is now basically a very early-stage bet on nanoparticle delivery and a possible competitor to Puma’s neratinib.

Oncothyreon acquired the private start-up Alpine Biosciences earlier this month, gaining Alpine’s protocell technology, in return for new equity that was then worth $27m. However, after the fall in Oncothyreon shares prompted by tecemotide’s latest failure, the stock with which Alpine’s private owners were paid is now worth 22% less.

The private investors included Alpine Bioventures, the fund set up by Mitchell Gold, former chief executive of Dendreon, to back the group. Jay Venkatesan, Alpine Biosciences’ founder and CEO, joined Oncothyreon as a vice-president with responsibility for the protocell technology.

Japanese failure

Yesterday’s tecemotide failure was in a phase I/II Japanese study in 178 NSCLC patients, in which the vaccine missed the primary efficacy benefit in overall survival, as well as all secondary endpoints, including improvement in progression-free survival.

Merck is to recommend that no Japanese patients be enrolled into the ongoing phase III programme. This comprises Start2, a 1,002-patient trial, as well as the Inspire study in 500 Japanese patients, started after tecemotide’s initial pivotal failure (Merck pushes on with failed cancer vaccine, September 25, 2013).

Speaking to EP Vantage at Asco Merck reaffirmed its confidence in tecemotide and insisted that the project was not a failure. Still, its future looks bleak; the premise of the new programme is tecemotide’s purported benefit in patients given concurrent chemoradiotherapy; yet this precise subgroup accounted for 94% of the patients in yesterday’s flunked Japanese trial.

Thus any real value in Oncothyreon, now capitalised at just under $200m, lies much earlier in the pipeline, for instance at the Alpine protocell business.

Protocells are nanoparticles designed to deliver a wide range of molecules, including small molecules and short interfering RNA fragments, as well as the more difficult proteins and nucleic acids. Oncothyreon’s view is that the huge potential of large molecules is being held back by an inability to deliver them.

Protocells attempt to overcome this thanks to their silica cores, whose large surface areas allow loading capacities up to 1,000 greater than is possible with liposomes. Moreover, Oncothyreon insists that this is not just a delivery platform but “a way to create unique products”.

If this is now set to become the group’s main focus the Alpine deal could look like a reverse takeover. Except, that is, for the presence of another potential hidden gem in the original Oncothyreon pipeline: the Her2 inhibitor ONT-380, partnered with another troubled biotech, Array Biopharma.

ONT-380 gained prominence in July after the huge success of Puma’s similarly acting neratinib in adjuvant breast cancer after one year’s Herceptin – effectively a new indication. Oncothyreon has stoked the fire, stating that ONT-380 is equipotent to neratinib against Her2, with improved tolerability.

Just one caveat: it is still in early phase I trials. Oncothyreon bulls will have to take the long view, and accept that yet more cash will be needed.

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

Share This Article