Dive Brief:
- Shares in Selecta Biosciences rose sharply Tuesday morning after the Massachusetts-based biotech reported progress from a Phase 2 trial of its lead candidate, an experimental gout medication that could sidestep a common shortcoming of existing drugs for the inflammatory condition.
- Preliminary results from the ongoing study of SEL-212 (SVP rapamycin plus pegsiticase) showed most patients who received a mid-level dose maintained serum uric acid control after repeat administration of the drug — suggesting SEL-212 helped to control gout symptoms.
- Uricases, a type of enzyme that metabolizes uric acid, can help eliminate uric acid crystal deposits in severe gout patients. But most patients quickly develop anti-drug antibodies that prevent further dosing. SEL-212, on the other hand, is designed to be non-immunogenic.
Dive Insight:
Selecta reported it had enrolled 38 patients in the Phase 2 trial as of March 23, with patients assigned to either a mid-dose level cohort, a low-dose level cohort or a control cohort.
Eleven of the 13 patients receiving mid-level dosing of SEL-212 continue to be dosed and have maintained serum uric acid control. One patient withdrew for a trial protocol deviation and another developed anti-drug antibodies.
As expected by Selecta, patients enrolled in the lower-dose cohort were much more likely to lose serum uric acid control, although four individuals sustained control through at least three months.
No serious adverse events (SAEs) were reported in the mid-dose cohort. Two infusion reactions, classified as SAEs, were observed in the low-dose cohort compared to one in the control cohort.
Selecta launched the Phase 2 study of SEL-212 in October of last year, and expects to complete the trial by the end of 2017. A Phase 3 study is slated to begin in 2018.
SEL-212 is a combination of the biologic pegsiticase with rapamycin delivered using Selecta's synthetic vaccine particles technology. In a Phase 1a study, pegsiticase alone reduced raised uric acid levels but triggered the development of anti-drug antibodies. The addition of SVP-rapamycin in a Phase 1b study reduced uric acid levels and prevented the development of antibodies.
Gout is a painful form of inflammatory arthritis caused by a buildup of uric acid, and can also lead to joint and organ damage. The condition affects around 8.3 million people in the U.S., with 3.1 million undiagnosed or untreated. Painkillers or anti-inflammatories are typically used to treat attacks and the risk of further breakouts can be reduced by drugs that lower uric acid production, but this is not always effective.