Drug-Drug Interaction Study of IV QPX2014 Combined With QPX7728 in Healthy Adult Subjects

Inclusion Criteria: 1. Healthy adult males and/or females of non-childbearing potential, 18 to 55 years of age (inclusive) at the time of screening. 2. Body mass index (BMI) ≥ 18.5 and ≤ 29.9 (kg/m2) and weight between 55.0 and 100.0 kg (inclusive) at the time of screening. 3. Medically healthy with clinically insignificant screening results (e.g., laboratory profiles, medical histories, electrocardiograms \[ECGs\], physical examination) as assessed by the PI. 4. Voluntarily consent to participate in the study. 5. Male volunteers must agree to be sexually abstinent or agree to use a condom when engaging in any sexual activity from study check-in (on Day -1) through 30 days following the last administration of the study drug, and to not donate sperm during this same period of time. If engaging in sexual activity with a female partner of childbearing potential, an additional method of birth control must be used. Approved additional methods of birth control include: 1. Intrauterine device (IUD) in place for at least 3 months prior to Day 1 through 30 days following the final dosing of the study drug. 2. Barrier method (diaphragm) for at least 14 days prior to Day 1 through 30 days following dosing of the study drug. 3. Stable hormonal contraceptive for at least 3 months prior to Day 1 through 30 days following dosing of the study drug. 4. Surgical sterilization (vasectomy) at least 6 months prior to Day 1. 6. Females of non-childbearing potential must be either postmenopausal (defined as 12 months spontaneous amenorrhea) with a serum FSH ≥ 40 mIU/mL or have undergone one of the following sterilization procedures at least 6 months prior to Day 1 (and is documented): 1. Bilateral tubal ligation; 2. Hysterectomy; 3. Hysterectomy with unilateral or bilateral oophorectomy; 4. Bilateral oophorectomy. Exclusion Criteria: 1. History or presence of significant (based on the PI assessment) cardiovascular, pulmonary, hepatic, renal, hematological, gastrointestinal, endocrine, immunologic, dermatologic, neurological, or psychiatric disease. 2. Positive pregnancy test at screening or check-in (Day 1) for women. 3. Positive urine drug/alcohol testing at screening or check-in (Day -1). A repeat test may be performed at the Investigator's discretion in circumstances where a positive result is suspected to be caused by consumption of non-illicit substances. 4. Positive pregnancy test at screening or check-in (Day 1) for women. 5. Positive testing for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), or hepatitis C antibodies (HCV). 6. History or presence of alcoholism or drug abuse within the 2 years prior to Day 1. 7. Use of more than an average of 5 packs/week of tobacco/nicotine-containing product within 6 months prior to Day 1. Subjects must agree to refrain from smoking within 48 hours prior to confinement and for the duration of the study. 8. Excessive intake of alcohol, defined as an average daily intake of greater than 2 standard drinks for women and 4 standard drinks for men, (1 bottle of beer (375mL) is equivalent to approximately 1.4 standard drinks, 1 glass of spirits (30mL) is equivalent to approximately 1 standard drink and 1 glass (150mL) of wine is equivalent to approximately 1.5 standard drinks). 9. Use of any prescription medication (with the exception of hormone replacement therapy for females) within 14 days prior to Day 1. 10. Use of any over-the-counter (OTC) medication, including herbal products, probiotics and vitamins, within the 7 days prior to Day 1. Up to 2 grams per day of acetaminophen is allowed for acute events at the discretion of the PI. 11. Use of antacids, H2 receptor blockers or proton pump inhibitors within 3 days prior to Day 1. 12. Documented hypersensitivity reaction or anaphylaxis to any medication, including beta-lactam antibiotics. 13. Blood donation or significant blood loss (i.e., \> 500 mL) within 56 days prior to Day 1. 14. Plasma donation within 7 days prior to Day 1. 15. Participation in another investigational clinical trial within 30 days prior to Day 1 or within 5 half-lives of the previous investigational drug, whichever is longer. 16. Surgery within the past three months prior to Day 1 determined by the PI to be clinically relevant. Minor surgeries allowed include laser vision, minor dental and tooth extraction, mole or basal cell skin removal, endoscopy, and biopsy. 17. Any significant acute illness (based on the PI assessment) within 30 days prior to Day 1. 18. QTcF interval \>450 msec for males and \>470 msec for females or history of prolonged QT syndrome at screening or check-in (Day -1). 19. Calculated creatinine clearance less than 80 mL/min (Cockcroft- Gault method) at screening or check-in (Day -1). 20. Subjects who have any clinically significant laboratory value abnormalities at screening or check-in (Day -1), in particular: 1. White blood cell count \< 3,000/mm3, hemoglobin \< 11g/dL. 2. Absolute neutrophil count \< 1,200/mm3 or platelet count \< 120,000/mm3. 21. Liver function abnormalities at screening or check-in (Day -1) (defined by an elevation in bilirubin, AST or ALT \> ULN for subjects based on age and sex). 22. Any other condition or prior therapy, which, in the opinion of the PI, would make the subject unsuitable for this study. 23. Participation in a previous QPX7728 or QPX7831 study. 24. Participation of research site staff, their close family, or significant others.