Why Ultragenyx Pharmaceutical Shares Are Plummeting Today - Ultragenyx Pharmaceutical (NASDAQ:RARE)

Earlier today, Ultragenyx Pharmaceutical Inc RARE released updated interim GTX-102 data, including Day 128 assessments from 9 patients.
The Overall CGI-C-AS score improved by 1 point in 5/6 patients (average 0.8) in Cohort 4 and 1 point in 2/3 patients (average 0.7) in Cohort 5.
Credit Suisse says that the result is slightly lower than Street expectations.
But the physicians' CS spoke to highlighted a very low bar for a clinically meaningful product, and higher loading doses/longer dosing period could potentially improve these initial results.
Additional efficacy metrics presented were supportive of clinical improvements.
The most common AE was vomiting, which may be related to the procedure and anesthesia.
Data from the U.S. cohort that was dosed at 2 mg showed a 2-point overall improvement in two evaluable patients. The ex-US study protocol is now amended to enroll two additional cohorts sequentially, Cohort 6 (younger, starting at 7.5 mg loading doses) and Cohort 7 (older, starting at 10 mg).
Management noted that higher loading doses could significantly improve the efficacy profile.
Price Action: RARE shares are down 13.70% at $52.66 during the market session on the last check Tuesday.

Ultragenyx Shares Tumble On Initial Efficacy Missing Expectations, This Analyst Sees 'Viable Path Forward"