1885. Efficacy and Safety of Omadacycline in Intravenous Drug Using (IVDU) and Hepatitis C-Positive (HCV+) Patients with Acute Bacterial Skin and Skin Structure Infections (ABSSSI): A Subgroup Analysis from the OASIS Tria
Session: Poster Abstract Session: Clinical Study with New Antibiotics and Antifungals
Saturday, October 7, 2017
Room: Poster Hall CD
Posters
  • 87779 ProEd_ID Week OASIS IVDU Pstr 7123 02OCT2017.pdf (404.7 kB)
  • Background: Skin infections are common in IVDU patients. HCV+ patients often have abnormal liver enzymes and transaminitis is a known tetracycline adverse effect. Omadacycline (OMC), is a novel, broad-spectrum aminomethylcycline related to tetracyclines. In OASIS, a phase 3 ABSSSI study, intravenous (IV)-to-oral OMC was non-inferior to IV-to-oral linezolid (LZD). Here, we report efficacy and safety of OMC vs LZD in IVDU and HCV+ patients from OASIS.

    Methods: 655 patients were randomized 1:1 to OMC 100 mg IV q12h × 2 doses then 100 mg IV q24h, or to LZD per label. After ≥ 3 days’ IV therapy, patients could transition to oral OMC 300 mg q24h or oral LZD. Total treatment duration was 7-14 days. Primary endpoint was early clinical response (ECR) assessed in the modified intent to treat (mITT) population. Secondary endpoints were clinical response at post-treatment evaluation (PTE) in the mITT and clinically evaluable (CE) populations. 322 patients were IVDU and 323 were non-IVDU; 168 were IVDU/HCV+ while 305 were non-IVDU/HCV-negative (–).

    Results: ECR rates with OMC and LZD were similar in IVDU vs non-IVDU patients and IVDU/HCV+ vs non-IVDU/HCV– patients. PTE responses with OMC in non-IVDU patients were significantly higher vs LZD. At PTE, OMC clinical success was lower in IVDU/HCV+ vs non-IVDU/HCV– patients. All subgroups displayed a generally similar and well-tolerated safety profile. There were no major differences in liver function tests across the subgroups and no OMC IVDU patient had a post-baseline ALT/AST greater than 3x the upper limit of normal.

    Conclusion:

    IV to once-daily oral OMC was effective, safe, and well-tolerated for treating ABSSSI irrespective of IVDU or HCV status.

    Table 1. ECR in mITT Population

    Subgroup

    Clinical Success, %

    Difference (95% CI)

    OMC

    LZD

    IVDU

    87.7

    86.4

    1.2 (–6.4, 8.8)

    Non-IVDU

    85.3

    86.9

    –1.6 (–9.6, 6.4)

    IVDU/HCV+

    85.4

    84.8

    0.6 (-10.4, 11.9)

    Non-IVDU/HCV–

    84.6

    87.3

    –2.7 (–11.0, 5.6)

    Table 2. PTE Responses

    Subgroup

    Clinical Success, %

    mITT

    CE

    OMC

    LZD

    Difference (95% CI)

    OMC

    LZD

    Difference (95% CI)

    IVDU

    78.1

    80.1

    –2.0 (-10.9, 6.9)

    94.4

    94

    0.4 (–5.9, 6.6)

    Non-IVDU

    94.2

    87.6

    6.6 (0.2, 13.7)

    97.9

    92.9

    5.0 (0.1, 11.1)

    IVDU/HCV+

    77.5

    79.7

    –2.2 (–14.6,10.5)

    93

    93.5

    –0.6 (–10.0, 9.4)

    Non-IVDU/HCV–

    94

    88.8

    5.2 (–1.4,12.3)

    97.8

    93.2

    4.6 (–0.4, 10.9)

    Christopher Ohl, MD, FIDSA1, Nancy Cure-Bolt, MD2, Surya Chitra, PhD, MBA3, Evan Tzanis, BA3 and Paul McGovern, MD3, (1)Department of Internal Medicine, Section on Infectious Diseases, Wake Forest School of Medicine, Winston-Salem, NC, (2)Paratek Pharmaceuticals, King of Prussia, PA, (3)Paratek Pharmaceuticals, Inc., King of Prussia, PA

    Disclosures:

    C. Ohl, None

    N. Cure-Bolt, Paratek Pharmaceuticals: Employee and Shareholder , Salary

    S. Chitra, Paratek Pharmaceuticals: Employee and Shareholder , Salary

    E. Tzanis, Paratek Pharmaceuticals: Employee and Shareholder , Salary

    P. McGovern, Paratek Pharmaceuticals: Employee and Shareholder , Salary

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