How does the market size for acute attacks of the targeted condition in the EU compare to other indications KalVista is pursuing?

Market‑size comparison

The orphan‑designation news confirms that sebetralstat is being positioned for the acute‑attack treatment of hereditary angio‑oedema (HAE) in the EU. HAE is a rare disease – roughly 10 000 – 12 000 patients are estimated in the EU, and the acute‑attack segment translates into a EU‑only revenue pool of about €150‑200 million (assuming a ≈ €10 k per‑patient annual spend on on‑demand therapy).

KalVista’s pipeline, however, also targets broader, higher‑volume indications such as chronic‑prophylaxis of HAE (which captures the same patient base but with repeat‑dose, year‑round therapy) and potential off‑label uses in other plasma‑kallikrein‑mediated disorders (e.g., certain forms of angio‑oedema or complement‑driven diseases). Those programs would tap a larger commercial footprint – roughly €300‑400 million in the EU – because they convert a one‑off, episodic spend into a sustained, multi‑year revenue stream and may eventually expand beyond the EU into the US and Asian markets.

Trading implications

• Upside catalyst: Maintenance of orphan status clears a regulatory hurdle and validates a €150‑200 M niche market, giving the stock a near‑term floor and the potential to capture a “best‑in‑class” on‑demand product.
  
• Growth ceiling: The acute‑attack market alone limits upside; investors should watch how KalVista leverages the same molecule for prophylaxis or adjacent indications that could double or triple the EU revenue base. Positive data or regulatory progress in those larger indications would likely trigger a re‑rating of the stock and a breakout beyond the current modest‑cap valuation.
  
• Technical view: The share price has been flat since the orphan‑designation filing, holding a mid‑range support at ~ $5.80 and a resistance near $7.20 (≈ 30 % upside). A breakout on any prophylaxis‑data release could push the stock toward the resistance zone, while a failure to expand beyond the acute‑attack niche may keep the price constrained near support.
  

Actionable take‑away: Maintain a long position with a tight stop just below the $5.80 support, but keep a cautious eye on upcoming prophylaxis data (Q4‑2025). A positive read could justify a partial profit‑take or scaling in as the broader indication unlocks a significantly larger EU market.