Access Pharmaceuticals Initiates Program Applying Cobalamin Platform to siRNA Drug Delivery
05 February 2010 - 1:00AM
PR Newswire (US)
Technology Is Seen As Providing Missing Link In Commercial
Development Of Promising siRNA Therapies DALLAS, Feb. 4
/PRNewswire-FirstCall/ -- ACCESS PHARMACEUTICALS, INC. (OTC
Bulletin Board: ACCP) announced today that it initiated an internal
pre-licensing program to confirm the utility of its proprietary
Cobalamin (vitamin B12) platform technology for targeted delivery
of siRNA therapies. The program is considered important because,
despite the widely publicized potential of RNA therapy, researchers
up to now have been stymied in their efforts to design a
pharmaceutical product that efficiently transports siRNA
therapeutics into the cells they are designed to inhibit or kill.
Access has multiple programs ongoing around use of its Cobalamin
technology to facilitate oral absorption of pharmaceuticals,
including previously announced collaborations with potential pharma
and biotech partners. To date, its successful Cobalamin product
development program has focused on the oral delivery of insulin and
human growth hormone, two peptides that currently can only be given
by injection. Because these two molecules share some of the same
physical characteristics as RNA's active components, Access
believes its Cobalamin technology could effectively deliver RNA
therapy in an oral tablet instead of by injection. But a more
compelling feature of the Cobalamin technology may be its ability
to overcome the cellular transport obstacles that have held back
fuller development of RNA therapy. The large size and high negative
charge of RNA molecules prevents their absorption by target cells.
Using the 'Trojan Horse' principle, the Cobalamin nanoparticle
technology can encapsulate small fragments of RNA (siRNA) and
utilize the Colalamin's vitamin B12 uptake mechanism to transport
them into target cells, allowing release of the active drug to
initiate the therapeutic effect. Cobalamin's vitamin B12 uptake
mechanism offers the potential for targeted delivery of siRNA
because most human cells have a requirement for vitamin B12. This
is served by cell surface receptors, which facilitate absorption of
this vitamin. In many diseases, the demand for vitamin B12 is
increased, with a corresponding upregulation of the receptor.
"Access scientists and collaborators have so far demonstrated in
preclinical models that Cobalamin formulations are effective in
achieving good oral drug delivery of charged peptides such as
insulin and human growth hormone," commented David P. Nowotnik,
Senior Vice President, Research and Development. "These successes
with molecules which share some of the same physical
characteristics as siRNA would indicate that we should now be able
to generate effective formulations of Cobalamin nanoparticles for
delivery of siRNA. We know already from previous work that we can
make cancer drugs more effective using the Cobalamin approach, and
so we have a sound scientific basis for the future development of
Cobalamin RNAi therapeutics." Cobalamin is Access' proprietary
technology based upon the use of vitamin B12 for targeted delivery
of drugs to disease sites and for oral drug delivery of drugs that
otherwise have poor oral bioavailability. Access has focused its
Cobalamin product development program on the oral delivery of
insulin and human growth hormone, two peptides that currently can
only be given by injection. Since presenting promising results at a
major conference in mid-2008, Access has made substantial
improvements to the formulation technology. A new Cobalamin-coated
insulin-containing nanoparticle formulation delivered orally
provided a pharmacological response (lowering of blood glucose
levels in an animal model of diabetes) equivalent to greater than
80% of that achieved by insulin delivered subcutaneously. This
represents a substantial oral bioavailability, indicating that this
formulation has potential for clinical development and ultimate
commercialization. Adaptation of this technology has provided a
Cobalamin human growth hormone formulation that has demonstrated
good efficacy, represented by more than 25% improvement in weight
gain, when given orally in an established animal model. Access
continues to move both products towards clinical development, and
plans to submit an additional patent application to protect the
improvements to the technology. About Access: Access
Pharmaceuticals, Inc. is an emerging biopharmaceutical company that
develops and commercializes propriety products for the treatment
and supportive care of cancer patients. Access' products include
ProLindac(TM) currently in Phase 2 clinical testing of patients
with ovarian cancer, and MuGard(TM) for the management of patients
with mucositis. The company also has other advanced drug delivery
technologies including Cobalamin(TM)-mediated targeted delivery and
oral drug delivery, its proprietary nanopolymer delivery technology
based on the natural vitamin B12 uptake mechanism and Thiarabine, a
new generation nucleoside analog which has demonstrated both
pre-clinical and clinical activity in certain cancers. For
additional information on Access Pharmaceuticals, please visit our
website at http://www.accesspharma.com/. This press release
contains certain statements that are forward-looking within the
meaning of Section 27a of the Securities Act of 1933, as amended,
and that involve risks and uncertainties. These statements include
those relating to: our cash burn rate, clinical trial plans and
timelines and clinical results for ProLindac, MuGard, Thiarabine
and Cobalamin and other product candidates, our ability to achieve
clinical and commercial success and our ability to successfully
develop marketed products. These statements are subject to numerous
risks, including but not limited Access' need to obtain additional
financing in order to continue the clinical trial and operations
and to the risks detailed in Access' Annual Reports on Form 10-K
and other reports filed by Access with the Securities and Exchange
Commission. Contact: Company Stephen B. Thompson Vice President,
Chief Financial Officer Access Pharmaceuticals, Inc. (214) 905-5100
Contact: Investor Relations Donald C. Weinberger/Alisa Steinberg
(media) Wolfe Axelrod Weinberger Assoc. LLC (212) 370-4500
DATASOURCE: Access Pharmaceuticals, Inc. CONTACT: Stephen B.
Thompson, Vice President, Chief Financial Officer, Access
Pharmaceuticals, Inc., +1-214-905-5100; or Investor Relations,
Donald C. Weinberger/Alisa Steinberg (media), Wolfe Axelrod
Weinberger Assoc. LLC, +1-212-370-4500 Web Site:
http://www.accesspharma.com/
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