Shares of Swiss biotechnology company Pharvaris more than quadrupled Thursday after one of its experimental drugs was able to reduce symptoms of a rare swelling disorder in a mid-stage trial.
Pharvaris is developing the drug for hereditary angioedema, a genetic condition characterized by unpredictable and painful swelling attacks. Several medicines from Takeda, CSL and others are approved to treat or prevent those episodes, but they have limitations. Pharvaris is one of several companies including Intellia Therapeutics and KalVista Pharmaceuticals that aim to improve on existing treatments — typically chronic injections — in one way or another.
Pharvaris aims to do so with an oral medicine which works by blocking signaling of a protein called bradykinin that’s implicated in swelling, giving it the potential to treat attacks as they happen or to prevent their onset. Pharvaris is developing two versions of the drug: a softgel capsule, PHVS416, that’s being tested as an on-demand treatment or prophylactic; and an extended release formulation, PHVS719, being evaluated as a preventive therapy.
Pharvaris has advanced PHVS416 into two Phase 2 clinical trials. But its plans were set back in August, when the Food and Drug Administration put those studies on hold in the U.S. following findings in preclinical tests. The agency asked the company to conduct a new long-term safety study in rodents.
The news sent Pharvaris shares tumbling by more than a quarter, and, over the next four months, the stock fell to its lowest levels since going public in February 2021. Still, Pharvaris had enrolled enough patients in one of the trials, known as RAPIDe-1, to accrue data.
The results from that trial were reported on Thursday, and PHVS416 met all of its main and secondary study goals. All tested doses led to a statistically significant reduction in pain and swelling symptoms, compared to a placebo, within four hours of an attack. The drug acted quickly, hitting marks for various levels of symptom reduction and reducing the need for other rescue medications, Pharvaris said.
There were no serious treatment-related adverse events, Pharvaris added, and no study participants dropped out of the study due to side effects.
The results sent Pharvaris’ shares soaring 357% on Thursday, as they’re “potentially competitive” with sebetralstat, a rival pill KalVista is developing to treat hereditary angioedema attacks, wrote SVB Securities analyst Joseph Schwartz in a research note.
Still, Pharvaris shares, which fell in Friday morning trading, are worth just over half their $20 debut price last year. And KalVista’s drug is well ahead, with a Phase 3 study ongoing that’s expected to report results in the second half of next year.
Pharvaris recently met with the FDA to try to resolve the agency’s concerns. It’s awaiting a formal response, but in the meantime still expects to produce results from its other Phase 2 trial in second half 2023.