(Reuters) – Sienna Biopharmaceuticals Inc said its lead experimental acne treatment failed to meet the main goals of two pivotal trials and that the chances of it clearing a third study appeared weaker, sending its shares tumbling 19 percent.

“The probability of success in the third acne trial certainly seems lower in light of the first two data sets,” Chief Executive Officer Frederick Beddingfield said on a conference call with analysts.

Results of the ongoing study on Sienna’s topical treatment, SNA-001, are expected in the fourth quarter, Sienna said.

In the latest studies, SNA-001, when administered before laser therapy to patients with moderate-to-severe acne vulgaris, did not show an additional benefit in reducing inflammatory lesions, when compared to those on the control arm of the study.

Despite the latest setback, the company said it had sufficient cash to continue ongoing trials over the next three quarters and into the third quarter of 2019.

As of March 31, Sienna had about $60 million in cash and cash equivalent.

SNA-001 is also being separately tested to reduce unwanted light-pigmented hair, but California-based Sienna noted the mechanism for removing hair is “relatively straightforward” compared to treating acne.

Shares of Sienna, which went public about a year ago, were down 13.8 percent at $13.53 in early trading.

(Reporting by Tamara Mathias and Aakash B in Bengaluru; Editing by Shailesh Kuber and Anil D’Silva)