Nabi Biopharmaceuticals Reports Encouraging Phase I/II Altastaph Results in Adults
ROCKVILLE, Md. -- Nabi Biopharmaceuticals today announced encouraging results from its U.S. Phase I/II clinical trial using Altastaph (Staphylococcus aureus Immune Globulin Intravenous (Human) to treat adult in-hospital patients with persistent
Staphylococcus aureus (S. aureus) bloodstream infections (bacteremia).
In this study there was a 36 percent reduction in median time from administration of the
study drug to hospital discharge in the Altastaph-treated patients as compared
to the placebo-treated patients (nine days in the Altastaph group versus 14
days in the placebo group). This substantial reduction in the length of
hospital stay for the Altastaph-treated group indicates that S. aureus
antibodies provided by Altastaph could be associated with considerable medical
benefit in the treatment of persistent S. aureus infections.
Altastaph is produced by immunizing healthy volunteers with StaphVAX
[Staphylococcus aureus Polysaccharide Conjugate Vaccine], Nabi
Biopharmaceuticals' vaccine in development for providing protection in at-risk
patients against S. aureus infections. S. aureus bacteria are the most
common cause of hospital-acquired infections and are becoming increasingly
resistant to antibiotics, which may result in illness and/or death.
The study was a double-blinded, placebo-controlled, randomized trial in 40
patients with persistent S. aureus blood stream infections (bacteremia)
designed to evaluate the safety of Altastaph and to measure S. aureus specific
antibody levels. Patients were randomly allocated to receive two intravenous
doses of Altastaph or saline placebo in combination with standard-of-care
treatment, which included treatment with antibiotics. The results of the
study demonstrated that Altastaph was well tolerated and no drug-related,
serious adverse events were reported. Patients were able to maintain antibody
titers at or above levels previously demonstrated to be protective against S.
aureus infections in patients with end-stage renal disease (ESRD). In
addition, as outlined above, Altastaph treatment was associated with a
substantial reduction in time to hospital discharge.
Thomas H. McLain, chairman, chief executive officer and president, Nabi
Biopharmaceuticals, stated, "We are very excited about seeing a meaningful
trend from a small safety and immunogenicity study that is supportive of the
benefit of Altastaph in the treatment of patients with a staph infection. We
believe this is the first well-designed clinical study that has demonstrated a
therapeutic benefit from an antibody therapy in patients with serious
infection. If we are able to duplicate these results in larger efficacy
studies, the high costs and serious complications associated with lengthy
hospital stays due to S. aureus bacterial infections could be significantly
reduced because patients treated effectively could go home sooner, greatly
reducing an increasing burden on the healthcare system." McLain
continued, "Further, the demonstrated potential for using Altastaph
therapeutically in patients with existing serious infections substantially
increases the possible commercial opportunity for Nabi Biopharmaceuticals'
Gram-positive programs."
"These results also provide additional validation of Nabi's unique
approach of using antibodies to the polysaccharide capsule of S. aureus
bacteria to prevent and treat infection," said Raafat Fahim, PhD, senior
vice president research, technical and production operations. "StaphVAX and
Altastaph share a common mechanism of action. When antibodies to S. aureus
attach to the outer capsule of the bacteria as it circulates in the blood, it
triggers an immune response, enabling the body's white blood cells to
recognize the bacteria and destroy it before it can contribute to more serious
infection."
Henrik Rasmussen, MD, PhD, senior vice president, clinical research,
medical and regulatory affairs, and project management, Nabi
Biopharmaceuticals, added, "Based on these results, we intend to advance our
current Altastaph formulation, which uses Type 5 and 8 antibodies, to further
assess its role in treating S. aureus infections. We plan to meet with both
U.S. and European regulatory authorities to share the data from this trial and
work with them to define the next clinical steps for Altastaph. Our
discussions will also consider recent clinical data from Brigham and Women's
Hospital (Clinical Infectious Diseases 2003; 36: 281-285), demonstrating that
patients treated for a serious staph infection and released from the hospital
are at a very high risk for a recurrence of another serious staph infection
within a relatively short period of time. We believe a combination therapy
approach like this one will capture the therapeutic and preventive benefits of
our unique approach in patients afflicted with these life threatening
infections."
Altastaph is an investigational human antibody-based product containing
high levels of antibodies to capsular polysaccharides (protective outer sugar
coatings on S. aureus bacteria) from S. aureus Types 5 and 8, which together
account for approximately 85 percent of all S. aureus infections. Altastaph is
produced by immunizing healthy volunteers with StaphVAX, Nabi
Biopharmaceuticals' vaccine in development for preventing S. aureus
infections.
Altastaph has been designated an orphan drug and has received Fast Track
Designation for providing immediate protection against S. aureus infections in
low birth-weight infants. Altastaph is also being developed prophylactically
to provide short-term, immediate protection to patients who either cannot wait
for the vaccine effect to occur or whose immune system is too compromised to
mount an adequate response to a vaccine.
An estimated 12 million patients are at risk for developing a S. aureus
infection each year in the U.S. alone. Within the country's 7,000 acute care
hospitals, S. aureus is the leading cause of hospital-acquired bloodstream
infections and is becoming increasingly resistant to antibiotics, rendering
them potent causes of illness and death with a crude mortality rate of
25 percent. Patients at the greatest risk for these infections are those who
are immune-compromised, patients whose treatment requires invasive devices
such as prosthetic devices, catheters, artificial hips or knees, dialysis
access grafts, pacemakers, implantable defibrillators, or patients with
chronic illnesses, especially if they are being cared for in hospitals,
nursing homes, dialysis centers or similar institutions.
Furthermore, S. aureus bacteria are becoming increasingly resistant to
available antibiotics. Worldwide it is estimated that over 95 percent of
patients with S. aureus infections no longer respond to first-line
antibiotics, such as penicillin or ampicillin. Methicillin is an alternative
treatment, but over 57 percent of strains of S. aureus are now Methicillin-
resistant (MRSA) in the United States. The Centers for Disease Control
estimate that in 2002 there were approximately 100,000 cases of hospital-
acquired MRSA infections in the United States and the problem of these
infections is only worsening. The rates of Methicillin-resistance are even
greater in certain Asian and European countries, (e.g., 72 percent MRSA rate in
Japan; 74 percent in Hong Kong).
Source: Nabi Pharmaceuticals
