Sangamo’s gene therapy gets Pfizer stamp of approval

Sangamo’s bold claim that its haemophilia A gene therapy SB-525 could be best in class has received a boost from an early tie-up with Pfizer. Although the project has yet to enter the clinic, Sangamo believes that it could be more potent than rival candidates from Spark Therapeutics and Biomarin, based on non-human primate data that were obviously enough to help it hook a partner.

For Pfizer, the agreement adds to a burgeoning gene therapy pipeline. In recent years the group has also sealed a deal with Spark in haemophilia B and acquired Bamboo Therapeutics, which has a phase I asset for giant axonal neuropathy. Gene therapy is a risky space, but Pfizer has made no secret of its desire to own it (see tables below).

Fresh blood

The Pfizer deal is the latest chapter in Sangamo’s turnaround – the company’s stock had risen 40% since the beginning of this year, and opened up another 50% today. Its reboot under a new chief executive, Sandy Macrae, appointed last June, seems to be paying off.

Under the agreement, Sangamo will receive $70m up front, but must fund a phase I/II trial of SB-525, slated to start this year. Pfizer will assume responsibilities for subsequent research, development and commercialisation of SB-525, and the California-based biotech would be eligible for up to $300m, with another $175m available for additional haemophilia A candidates.

SB-525 will join Spark Therapeutics’ SPK-8011 and Biomarin’s BMN-270 as clinical-stage factor VIII gene therapies.

Spark and Biomarin are already in the clinic with their rival haemophilia A gene therapies but Sangamo clearly believes it still has a chance, and has touted promising preclinical research. The group has highlighted primate data showing an average peak factor VIII level of 229% of normal, versus 153% with SPK-8011 and 33% with BMN 270.

Of course it will now need to replicate this in the clinic – but, with Pfizer now behind it, confidence in Sangamo’s project could increase.

Partners

Haemophilia A is not the only area where Sangamo has sought collaborators. It already has deals in place for preclinical projects in beta thalassemia and sickle cell disease, with the Biogen spin-off Bioverativ, and in Huntington’s disease with Shire.

It also has a phase II HIV candidate, SB-728, but has said it does not plan to invest further in this without a partner.

The rest of its clinical-stage pipeline is focused on in vivo gene editing via Zinc-finger nucleases, a technology that has been somewhat eclipsed recently by other genome-editing systems like Talens and Crispr/Cas9. Initial data with these projects should be available by the end of 2017 or early 2018.

But it is Sangamo’s gene therapy platform that has now grabbed the headlines. The move raises the question of why it was the Californian company, rather than existing partner Spark, that managed to lure Pfizer into a deal. Spark’s shares were down as much as 3% this morning.

As clinical data begin to emerge, it should start becoming clearer whether Sangamo’s asset was just more reasonably priced, or whether it is indeed better.