SESSION TITLE: Signs and Symptoms of Chest Disease Abstract PostersSESSION TYPE: Original Investigation PostersPRESENTED ON: 10/18/2022 01:30 pm - 02:30 pmPURPOSE: The lack of approved treatment for refractory chronic cough (RCC) increases the burden on patients by resulting in multiple cycles of medical consultations, diagnostic investigations and trials of therapy. The development of P2X3 antagonists for the treatment of RCC has opened the possibility to alleviate this burden in the future. To better understand the current experience of RCC patients, we report the prior specialty consultations and treatments in a RCC population enrolled in a phase 2b study of BLU-5937, a selective P2X3 antagonist.METHODS: SOOTHE (NCT04678206) was a multi-center phase 2b, randomized, placebo-controlled, parallel arm clinical dose-finding study in participants diagnosed with RCC for ≥1 year and with an awake cough frequency ≥25 coughs/h. Patients included also had to report a cough severity of at least 40 mm on a 100 mm visual analog scale. A FEV1/FVC score of at least 60% was also necessary for inclusion. Patients with a diagnosis of COPD, bronchiectasis or IPF were excluded from the study. Prohibited medications during the study included anti-tussive therapy, gabapentin, pregabalin, baclofen, tricyclic antidepressants, systemic corticosteroids and ACE inhibitors. Following a single-blind run-in period, 249 participants who had maintained a baseline awake cough frequency ≥25 coughs/h were randomized 1:1:1:1 to the three active treatment arms of BLU-5937 (12.5, 50 and 200 mg BID) or placebo for 4 weeks of double-blind treatment.RESULTS: Ninety-four percent of patients enrolled in SOOTHE had seen at least one specialist prior to the study. Pulmonologists were the specialists most often consulted, with 78% of participants having seen at least one. Moreover, 59% had consulted with an ENT specialist, 50% with an allergist or immunologist and 46% with a gastroenterologist. A speech language pathologist had been seen by 16% of participants. Patients enrolled in the main population of SOOTHE had received an average of 5.2 ±3.1 treatments related to their cough prior to the start of the trial. Interestingly, 31% were diagnosed with asthma but 73% had received at least one prior treatment for the condition; 46% were diagnosed with GERD but 77% had received at least one prior treatment; 26% were diagnosed with UACS but 70% had received at least one prior treatment. Overall, the most common prior medications included acid reducers (76%), inhaled bronchodilators (56%) and oral antihistamines (51%).CONCLUSIONS: Overall, the broad range of specialists seen by RCC patients reflect the evaluation needed to establish the diagnosis.CLINICAL IMPLICATIONS: The large number of specialists consulted, and treatments attempted demonstrate the burden put on patients and healthcare systems by RCC.DISCLOSURES: Consultant relationship with Bellus Please note: 3/19-current Added 03/25/2022 by Michael Blaiss, value=HonorariaSpeaker/Speaker's Bureau relationship with Merck Please note: 3/19-current Added 03/25/2022 by Michael Blaiss, value=Honorariano disclosure submitted for Catherine Bonuccelli;Consultant relationship with Merck Please note: 2017-2021 by Peter Dicpinigaitis, value=Consulting feeConsultant relationship with Bayer Please note: 2019-2021 Added 03/25/2022 by Peter Dicpinigaitis, value=Consulting feeConsultant relationship with Bellus Please note: 2019-2022 Added 03/25/2022 by Peter Dicpinigaitis, value=Consulting feeConsultant relationship with Bellus Please note: 2019-2022 Added 03/25/2022 by Peter Dicpinigaitis, value=Consulting feeRemoved 03/25/2022 by Peter DicpinigaitisConsultant relationship with Shionogi Please note: 2019-2022 Added 03/25/2022 by Peter Dicpinigaitis, value=Consulting feeConsultant relationship with Chiesi Please note: 2020-2022 Added 03/25/2022 by Peter Dicpinigaitis, value=Consulting feeEmployeeNo relevant relationships by Vivek IyerEmployee relationship with Bellus Health Please note: 2020-2022 Added 03/16/2022 by Sylvain Lanouette, value=SalaryConsultant relationship with Bellus Health Please note: 2020-2022 Added 03/26/2022 by Lorcan McGarvey, value=Consulting feeScientific Medical Advisor relationship with Merck Please note: $1001 - $5000 by Jaclyn Smith, value=Consulting feeScientific Medical Advisor relationship with Vitalograph Ltd Please note: $5001 - $20000 by Jaclyn Smith, value=Grant/Research SupportGrant Funding relationship with Merck Please note: 2020-2022 by Jaclyn Smith, value=Grant/Research SupportConsultantEmployee SESSION TITLE: Signs and Symptoms of Chest Disease Abstract Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/18/2022 01:30 pm - 02:30 pm PURPOSE: The lack of approved treatment for refractory chronic cough (RCC) increases the burden on patients by resulting in multiple cycles of medical consultations, diagnostic investigations and trials of therapy. The development of P2X3 antagonists for the treatment of RCC has opened the possibility to alleviate this burden in the future. To better understand the current experience of RCC patients, we report the prior specialty consultations and treatments in a RCC population enrolled in a phase 2b study of BLU-5937, a selective P2X3 antagonist. METHODS: SOOTHE (NCT04678206) was a multi-center phase 2b, randomized, placebo-controlled, parallel arm clinical dose-finding study in participants diagnosed with RCC for ≥1 year and with an awake cough frequency ≥25 coughs/h. Patients included also had to report a cough severity of at least 40 mm on a 100 mm visual analog scale. A FEV1/FVC score of at least 60% was also necessary for inclusion. Patients with a diagnosis of COPD, bronchiectasis or IPF were excluded from the study. Prohibited medications during the study included anti-tussive therapy, gabapentin, pregabalin, baclofen, tricyclic antidepressants, systemic corticosteroids and ACE inhibitors. Following a single-blind run-in period, 249 participants who had maintained a baseline awake cough frequency ≥25 coughs/h were randomized 1:1:1:1 to the three active treatment arms of BLU-5937 (12.5, 50 and 200 mg BID) or placebo for 4 weeks of double-blind treatment. RESULTS: Ninety-four percent of patients enrolled in SOOTHE had seen at least one specialist prior to the study. Pulmonologists were the specialists most often consulted, with 78% of participants having seen at least one. Moreover, 59% had consulted with an ENT specialist, 50% with an allergist or immunologist and 46% with a gastroenterologist. A speech language pathologist had been seen by 16% of participants. Patients enrolled in the main population of SOOTHE had received an average of 5.2 ±3.1 treatments related to their cough prior to the start of the trial. Interestingly, 31% were diagnosed with asthma but 73% had received at least one prior treatment for the condition; 46% were diagnosed with GERD but 77% had received at least one prior treatment; 26% were diagnosed with UACS but 70% had received at least one prior treatment. Overall, the most common prior medications included acid reducers (76%), inhaled bronchodilators (56%) and oral antihistamines (51%). CONCLUSIONS: Overall, the broad range of specialists seen by RCC patients reflect the evaluation needed to establish the diagnosis. CLINICAL IMPLICATIONS: The large number of specialists consulted, and treatments attempted demonstrate the burden put on patients and healthcare systems by RCC. DISCLOSURES: Consultant relationship with Bellus Please note: 3/19-current Added 03/25/2022 by Michael Blaiss, value=Honoraria Speaker/Speaker's Bureau relationship with Merck Please note: 3/19-current Added 03/25/2022 by Michael Blaiss, value=Honoraria no disclosure submitted for Catherine Bonuccelli; Consultant relationship with Merck Please note: 2017-2021 by Peter Dicpinigaitis, value=Consulting fee Consultant relationship with Bayer Please note: 2019-2021 Added 03/25/2022 by Peter Dicpinigaitis, value=Consulting fee Consultant relationship with Bellus Please note: 2019-2022 Added 03/25/2022 by Peter Dicpinigaitis, value=Consulting fee Consultant relationship with Bellus Please note: 2019-2022 Added 03/25/2022 by Peter Dicpinigaitis, value=Consulting fee Removed 03/25/2022 by Peter Dicpinigaitis Consultant relationship with Shionogi Please note: 2019-2022 Added 03/25/2022 by Peter Dicpinigaitis, value=Consulting fee Consultant relationship with Chiesi Please note: 2020-2022 Added 03/25/2022 by Peter Dicpinigaitis, value=Consulting fee Employee No relevant relationships by Vivek Iyer Employee relationship with Bellus Health Please note: 2020-2022 Added 03/16/2022 by Sylvain Lanouette, value=Salary Consultant relationship with Bellus Health Please note: 2020-2022 Added 03/26/2022 by Lorcan McGarvey, value=Consulting fee Scientific Medical Advisor relationship with Merck Please note: $1001 - $5000 by Jaclyn Smith, value=Consulting fee Scientific Medical Advisor relationship with Vitalograph Ltd Please note: $5001 - $20000 by Jaclyn Smith, value=Grant/Research Support Grant Funding relationship with Merck Please note: 2020-2022 by Jaclyn Smith, value=Grant/Research Support Consultant Employee