What happened

Shares of Sangamo Therapeutics (SGMO 2.03%), a clinical-stage biopharmaceutical company developing gene therapies, are on the move following a data update late Friday night. Investors encouraged about the company's hemophilia candidate, SB-525, pushed the stock 16.9% higher in early morning trading, but the stock was up just 7.4% as of 12:35 p.m. EDT on Monday.

So what 

At a conference in Australia, Sangamo released a new set of results for a small group of hemophilia patients who received the highest dose so far of SB-525. A handful of different gene therapies that help hemophilia patients produce the clotting factor they need to avoid uncontrolled bleeding events are making their way toward commercialization. Early signs of clotting factor activity among patients treated with a high dose of SB-525 combined with a lack of bleeding events suggests it has a good chance to outperform similar candidates from BioMarin (BMRN -9.90%) and Spark Therapeutics (ONCE) despite being far behind on the development timeline. 

Cash raining down on an investor looking at their phone.

Image source: Getty Images.

The latest two patients given a single dose of SB-525 recently completed follow-up observations that show rapid clotting factor activity shortly after infusion, and one even achieved normal clotting factor levels after just seven weeks.

Now what

Sangamo's treatment has a good chance to catch up with potential competition from BioMarin and Spark Therapeutics because Pfizer's (PFE -3.85%) responsible for the heavy lifting following the ongoing dose determination study. Pfizer doesn't exactly need help moving drugs through regulatory hoops, but it could have a lot more now that former FDA commissioner Scott Gottlieb has been given a seat on its board of directors.

Under Gottlieb's leadership, the FDA's stance toward gene therapy development has been increasingly favorable, but convincing end payers that a one-time treatment is worth a seven-figure price tag will be the real challenge here.

It appears that BioMarin's treatment loses efficacy over time, which will make it tough for the company to demand such a high price. It's going to take another couple years to know if SB-525 is more durable, but it's off to a great start.