- KalVista Pharmaceuticals said its experimental, oral drug for the rare disease hereditary angioedema succeeded in a mid-stage trial, reporting Tuesday that significantly fewer patients given the pill after suffering one of the disease's hallmark swelling attacks needed injectable "rescue" drugs than those who received a placebo.
- The drug, code-named KVD900, was able to relieve symptoms about as well as some of the established injectable drugs like Takeda's Firazyr or Pharming's Ruconest, leading Wall Street analysts to believe the treatment has a good chance of succeeding commercially should it get through late-stage testing.
- Company executives said they expect to meet with the Food and Drug Administration in coming months to discuss the design of a Phase 3 trial aimed at gaining approval. Kalvista shares nearly doubled in price in midday trading, changing hands at $28.35 apiece.
Hereditary angioedema, or HAE, can cause life-threatening episodes that involve swelling of the throat or intestines, along with the face and extremities.
While it affects an estimated 1 in 100,000 people, HAE has numerous acute treatments, including fresh frozen plasma, Firazyr, Ruconest, and an androgen therapy called danazol. Treatments to prevent attacks have also been developed, such as Takeda's Cinryze, and more recently, BioCryst's Orladeyo.
Despite the small size of the market, HAE treatments are lucrative for drugmakers. Takeda, for example, earned 129.8 billion yen ($1.2 billion) in revenue from three HAE drugs in the 12 months ending March 31, 2020.
There is room for improvement as well. All treatments for HAE attacks are injectable. KalVista aims to show its oral treatment can be just as effective as others and safe enough to use whenever an attack occurs, which could represent a compelling alternative to standard care.
The main goal of KalVista's Phase 2 trial of KVD900 was to prevent the use of other acute treatments as "rescue" medications. When compared to placebo, it succeeded, with 15% of patients given KVD900 needing rescue drugs within 12 hours of treatment compared with 30% of those given a placebo.
Secondary goals compared KVD900 to existing acute drugs based on symptomatic relief. For example, in tests to approve Ruconest, the drug relieved symptoms a median of 1.5 hours after treatment. Though cross-trial comparisons should be treated with caution, patients on KVD900 experienced symptom relief in a median of 1.6 hours.
The achievement of "injectable-like" effectiveness in a pill should give KVD900 a good shot at competing against incumbent products, Stifel analyst Paul Matteis wrote in a Feb. 9 note. HAE specialists "suggested than an oral medicine with close to injectable-like efficacy could be a preferred product in the acute space," he wrote.
In addition, analysts believe a convenient drug for attacks would encourage some patients with mild and moderate disease now taking preventive medications to stop treatment.