Sienna concedes failure in pivotal acne trial — will the laser-managed therapy work in hair reduction?
Sienna Biopharmaceuticals’ first foray into pivotal trials is a bust.
The Westlake Village, CA biotech reported that its lead therapy, SNA-001, flunked two separate trials designed to test its efficacy when managed by laser tech. Shares $SNNA are down 20% in pre-market trading.

Instead of separating the patients into drug and control arms, researchers adopted a split-face method in which each side of the patient’s face got treated with laser and either SNA-001 or vehicle. Both treatments reduced acne lesion count from baseline — the primary endpoint — to a similar extent, and the differences were not significant in either the 810 nm laser (p=0.663) or 1064 nm laser (p=0.411) trial, which recruited 78 and 89 subjects respectively.
The p-values were similarly unimpressive for the secondary endpoints.
“These data are clear and unambiguous,” CEO Frederick Beddingfield said in a conference call, noting that his team did everything right, running a clean clinical program in search of definite outcomes. Subset analyses aren’t likely to happen.
While the execs are waiting for the results from a third trial coming in by the end of the year to make a decision, Beddingfield admitted the probability of success there “certainly seems lower” now.
He was quick to add that acne has been considered their smallest opportunity for SNA-001: The reduction of unwanted light-pigmented hair — with pivotal readout expected in Q4 — works via a simpler mechanism, requires a simpler procedure, and offers a lower hurdle for showing efficacy.
Sienna, which counts Robert Nelsen at Arch Ventures and Partner Fund Management among its investors, completed its $65 million IPO around this time last year boasting a two-pronged development strategy. SNA-001 came out of their topical photoparticle therapy platform; on the other side of the pipeline they have SNA-120 and SNA-125, two transdermal therapies for inflammatory skin diseases and pruritus they picked up from the acquisition of Creabilis.
Cash on hand is sufficient, Beddingfield said, to get the company through all of their data readouts, including a Phase II pruritus and psoriasis trial for SNA-120 and first-in-human studies for the JAK3/TrkA inhibitor SNA-125.