** Shares of biotech firm Q32 Bio QTTB.O jumps 56% to $17.54 premarket

** Co says bempikibart helped patients with alopecia areata, an autoimmune disease that causes patchy or severe hair loss when the immune system attacks hair follicles

** Patients treated for 36 weeks saw a 35.3% average improvement in hair regrowth, measured by SALT score, which measures the percentage of scalp affected by hair loss

** About 40% of patients achieved significant scalp hair coverage, the company said

** Trial enrolled 33 patients, including some who had previously received JAK inhibitors, a common class of alopecia treatments

** Co plans a larger registration-focused study in 2027 and expects to present additional results at a future medical meeting