1154. Evaluation of Digital vs. Manual Measures of Lesion Size in a Phase 3 Trial of Delafloxacin (DLX) in Patients with Acute Bacterial Skin and Skin Structure Infections (ABSSSI)
Session: Poster Abstract Session: Clinical Infectious Diseases: Bone and Joint, Skin and Soft Tissue
Friday, October 28, 2016
Room: Poster Hall
Posters
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  • Background: The primary endpoint in the FDA guidance on development of antibiotics for ABSSSI requires at least 20% reduction in lesion size at 48-72h after start of therapy.  Either manual measures (MM) or digital measures (DM) may be used, but assessment of the correlation of these methods has been limited.  A phase 3 ABSSSI trial of DLX vs vancomycin (VAN) used MM and DM to document the resolution of the infected lesion during the study and these measures were compared to assess the reliability and correlation of these methods.

    Methods: Adult patients with ABSSSI were enrolled in a randomized, double-blind trial of DLX vs. VAN with aztreonam. Measurements of lesion size were performed at baseline, at 48-72 hr after start of treatment and at other defined time-points including End of Treatment (EOT).  A disposable ruler was used for the MM of the longest length and the perpendicular width of the lesion. DM were performed by digital planimetry of the photographed lesion, which had been contoured by the investigator with a disposable marker.  Analysis compared the MM and DM.

    Results: 660 patients enrolled in the study. At baseline, the mean lesion size from DM and MM was 306.98 cm2 and 510.70 cm2 respectively. Using all corresponding DM and MM at all timepoints, the two methods correlated well, with correlation coefficient of 0.933. At 48-72h after the initiation of therapy, the DM method and MM showed similar percentages of subjects in which treatment stopped the spread of lesion (94.4% vs. 94.2%, respectively) as well as at least 20%  reduction in lesion size (85.7% vs. 87.8%, respectively). At EOT, the DM and MM showed similar percentages of subjects in which treatment resulted in at least 70% reduction in lesion size (86.4% vs. 88.1%, respectively) as well as at least 90%  reduction in lesion size (61.3% vs. 64.6%, respectively).

    Conclusion: Manual measurements consistently exceeded digital measurements as expected, given manual surface areas were calculated as a rectangle. The two methods correlated well, with comparable assessments of percent change from baseline over time. Either manual or digital measurement methods could serve as the primary source of data on lesion size and response to therapy by showing percent change in lesion size.

    Michael Jaharis, B.S.c.1, Dipali Patel, M.P.H.1, Laura Lawrence, B.S.1, Megan Quintas, BS1, Carol Tseng, Ph.D.2 and Sue K. Cammarata, M.D.1, (1)Melinta Therapeutics, Inc., New Haven, CT, (2)H2O Clinical LLC, Hunt Valley, MD

    Disclosures:

    M. Jaharis, Melinta Therapeutics, Inc.: Consultant , Consulting fee

    D. Patel, Melinta Therapeutics, Inc.: Consultant , Consulting fee

    L. Lawrence, Melinta Therapeutics, Inc.: Employee , Salary

    M. Quintas, Melinta Therapeutics, Inc.: Employee , Salary

    C. Tseng, H2O Clinical LLC: Consultant , Consulting fee

    S. K. Cammarata, Melinta Therapeutics, Inc.: Employee , Salary

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.