1341. Correlation of Lesion Size Changes and Pain in Acute Bacterial Skin and Skin Structure Infections (ABSSSI) Clinical Trials: Reflecting How “Patients Feel
Session: Poster Abstract Session: Clinical Trials
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
  • Association of Lesion Size Changes and Pain in Acute Bacterial Skin and Skin Structure Infection (ABSSSI) Clinical Trials Reflecting How Patients Feel (De Anda et al.) IDWeek 2013.pdf (407.1 kB)
  • Background: The US Food and Drug Administration (FDA) defines valid endpoints as those that directly measure how patients "feel, function or survive". The FDA ABSSSI guidance specifies the clinician reported outcome (ClinRO) of measurements of lesion area as the primary outcome measure of therapeutic effect. Lesion size is an indirect measure of patient benefit compared to patient reported outcomes (PROs) of reduction in pain which are direct measures of patient benefit.


    Methods: In the present study, we sought to determine whether during and after the treatment period, changes in lesion area are correlated with changes in pain level, a direct measure of  how patients "feel". This large global phase 3 study collected ABSSSI lesion size measurements and data from two different PRO pain scales (Visual Analog Scale [VAS] and Faces Rating Scale [FRS] ) at the baseline, Day 2, 48-72 Hour, and End of Therapy (Day 10-13) visits. 


    Results: 667 patients were randomized 1:1 to tedizolid phosphate or linezolid.   Figure 1 presents the correlation of the ClinRO of percent change from baseline in lesion area and the PRO of pain by the VAS.  The median pain level, as measured by the VAS, decreases as the lesion area decreases in size.  Data from the FRS also shows a similar association between lesion area size and pain score. 

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    Conclusion: The size of the ABSSSI lesion is well correlated with how the patient feels. Demonstration of this correlation is the first step in demonstrating that treatment effects on a ClinRO reflects treatment effects on direct patient benefits as measured by a PRO. Future studies in ABSSSI should incorporate direct measures of patient pain as well as lesion size measurements.

    Carisa De Anda, PharmD1, Edward Fang, MD2, Anita Das, PhD3, John Powers, MD, FIDSA4 and Philippe Prokocimer, MD2, (1)Trius Therapeutics, San Diego, CA, (2)Trius Therapeutics, Inc, San Diego, CA, (3)Axistat Inc, San Francisco, CA, (4)Medicine, George Washington University School of Medicine, Bethesda, MD


    C. De Anda, None

    E. Fang, None

    A. Das, None

    J. Powers, None

    P. Prokocimer, None

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