Kyverna Therapeutics (KYTX) Study update summary

Study design and patient population

• KYSA-8 is a single-arm, multicenter, open-label, phase II trial in Stiff Person Syndrome (SPS) with 26 patients who discontinued immunotherapies before miv-cel dosing.

• KYSA-6 is a phase II trial in generalized Myasthenia Gravis (gMG) with seven patients who failed prior immunotherapies and stopped them before miv-cel treatment.

• Both studies focus on patients with severe disease and high unmet needs who failed prior therapies.

• Over 100 patients have been treated with miv-cel across autoimmune indications, showing consistent safety and efficacy.

Efficacy results in SPS (KYSA-8)

• At one year, 95% of SPS patients maintained clinically meaningful improvement in the timed 25-ft walk test, with 24 of 26 remaining off immunotherapies.

• Median walk time reduced by 49% from baseline at one year, with over one-third achieving healthy adult walking speed.

• Statistically significant improvements were sustained across all primary and secondary endpoints at one year.

• 67% of patients who previously needed walking aids walked unassisted at one year.

• 92% of patients remained free of immunomodulatory or immunosuppressant therapies for SPS at one year.

Efficacy results in gMG (KYSA-6)

• All seven gMG patients showed rapid and robust improvements in MG-ADL and QMG scores, sustained for at least one year.

• Mean MG-ADL improvement was 8.2 points at 52 weeks; QMG improved by 12.8 points at 52 weeks.

• 100% of patients achieved clinically meaningful responses in MG-ADL, QMG, and MGC; 57% sustained minimal symptom expression at last follow-up.

• Nearly all patients remained off chronic immunotherapies, reducing treatment burden.

• 86% of gMG patients remained off immunosuppressants at last follow-up.