Telitacicept for the Treatment of Connective Tissue Disease-associated Thrombocytopenia

Overall response (CR + PR) rate

Response is deemed as complete (CR) if the platelet (PLT) count is ≥ 100×10\^9/L, partial (PR) if the platelet count ranges from 50×10\^9/L to 100×10\^9/L and at least doubled from baseline. No active bleeding is allowed in participants classified as CR or PR.

Overall response (CR + PR) rate

Response is deemed as complete (CR) if the platelet count is ≥ 100×10\^9/L, partial (PR) if the platelet count ranges from 50×10\^9/L to 100×10\^9/L and at least doubled from baseline. No active bleeding is allowed in participants classified as CR or PR.

Rescue treatment rate

Rescue treatment is initiated if the platelet count is \<10×10\^9/L, or the participant is with active bleeding, or based on the investigator's judgement when the platelet count ranges from 10×10\^9/L to 30×10\^9/L.

Time to rescue treatment

Time to rescue treatment refers to period duration from the initiation of Telitacicept or placebo (day 1) to rescue treatment.

Relapse rate

No response refers to the platelet count is \< 50×10\^9/L, or increases for less than 1-fold from baseline, or with active central nervous system or digestive tract bleeding, or rescue treatment is initiated. Relapse is defined as no response recurring after a complete or partial response lasting for at least 7 days with treatment.

life quality 1

According to the ITP Patient Assessment Questionnaire™ (ITP-PAQ™) score. The ITP-PAQ™ is a disease-specific instrument that was designed to measure the Quality of Life (QoL) of adult patients with immune thrombocytopenia. The items employ a 4-week recall with responses recorded on 4-, 5- or 7-point Likert scales. All item scores are transformed to a 0 to 100 continuum where higher scores represent better QoL and are weighted equally to derive the scale scores.

life quality 2

According to the FACT-Th6 score. The Functional Assessment of Cancer Therapy-Thrombocytopenia (FACT-Th6) consists of 6 questions in which patients rate (0-4) their general degree of worry related to bleeding and bruising, and resulting activity impairment and frustration. Items were reverse-scored as necessary such that higher scores represent higher Health-related quality of life (HRQoL). Total scores ranged from 0 to 24. Recall period is previous 7 days.

Absolute change rate from baseline in serum immunoglobulin G (IgG)

(serum IgG level at week 24-serum IgG level at baseline)/ serum IgG level at baseline

Absolute change rate from baseline in serum immunoglobulin M (IgM)

(serum IgM level at week 24-serum IgM level at baseline)/ serum IgM level at baseline