Kyverna Therapeutics is trading at $6.69, down 5.4%, as biotechnology and major indexes fall amid multi-year-high Treasury yields, pressuring rate-sensitive growth stocks. - Opening-session weakness reversed the positive reaction to September 24 clinical news. - The company reported durable one-year miv-cel responses and favorable safety data in stiff person syndrome and generalized myasthenia gravis. - No stronger company-specific negative catalyst was identified.