Sorrento Therapeutics, Inc. and IGDRASOL Announce Three Presentations on Cynviloq™ (IG-001; paclitaxel polymeric micelle) at

   Sorrento Therapeutics, Inc. and IGDRASOL Announce Three Presentations on
 Cynviloq™ (IG-001; paclitaxel polymeric micelle) at the American Association
                      of Cancer Research (AACR) Meeting

IGDRASOL will present updates on Cynviloq™, its late clinical stage paclitaxel
nanoparticle formulation. Highlights include the therapeutic evaluation of
Cynviloq™ in poorly perfused tumors as well as the potential development of
Cynviloq™-based personalized paclitaxel cancer therapy.

PR Newswire

SAN DIEGO and FOUNTAIN VALLEY, Calif., March 31, 2013

SAN DIEGO and FOUNTAIN VALLEY, Calif., March 31, 2013 /PRNewswire/ --Sorrento
Therapeutics, Inc. ("STI"; SRNE) and IGDRASOL announced today that IGDRASOL
will be presenting updates of its development of Cynviloq™ (IG-001) at the
annual meeting of the American Association for Cancer Research (AACR) in
Washington, DC (April 6^th to 10^th). IGDRASOL is a privately-held company
for which STI was granted an irrevocable option right to acquire. The two
companies' combined pipeline features an oncology franchise of potential
products with Phase 2 data for multiple solid tumor indications as well as two
synergistic drug discovery and development platforms, namely the G-MAB® human
antibody library and MABiT™, a proprietary technology to generate antibody
formulated drug conjugates (AfDC).

Cynviloq™ (or IG-001) is a next-generation, branded, micellar diblock
copolymeric paclitaxel formulation currently approved and marketed in several
countries as Genexol-PM®. Cynviloq™ has completed Phase 1 or 2 trials in MBC,
NSCLC, pancreatic cancer, ovarian cancer and bladder cancer in the U.S. and/or
non-U.S. IGDRASOL is preparing for an "End of Phase 2" meeting with the U.S.
Food & Drug Administration (FDA) targeted for the first half of 2013 regarding
Cynviloq™. As an injectable nanoparticle formulation of paclitaxel, Cynviloq™
is potentially eligible for approval via FDA's 505(b)(2) bioequivalence
regulatory pathway versus albumin-bound paclitaxel (nab-paclitaxel; Abraxane®)
in its currently approved MBC and NSCLC indications. Abraxane® sales exceeded
$400 million in MBC in fiscal 2012.

The time, title, authors and location of the presentations are as follows:

1.Mon, Apr 8, 1:00 - 5:00 PM (2141/10) – "IG-001 utilization of albumin
    mediated transport and its potential application in difficult to perfuse
    tumors." Kouros Motamed, Larn Hwang, Chao Hsiao, Vuong Trieu. IGDRASOL,
    Fountain Valley, CA. Poster Session, PO.ET01.03. Novel Targeted Therapies
    1.
2.Tue, Apr 9, 1:00 - 5:00 PM (3481/27) – "Development of personalized
    paclitaxel therapy (IG-001) for ovarian cancer." Larn Hwang, Chao Hsiao,
    Kouros Motamed, Vuong Trieu. IGDRASOL, Fountain Valley, CA. Poster
    Session, PO.CL13.08. Biomarkers 5: Breast and Gynecologic Cancers.
3.Tue, Apr 9, 1:00 - 5:00 PM (4526/24) – "IG-001 - Evaluation as next
    generation nanoparticle paclitaxel against poorly perfused tumors." Vuong
    Trieu, Larn Hwang, Kouros Motamed, Chao Hsiao. IGDRASOL, Fountain Valley,
    CA. Poster Session, PO.CH06.01. Drug Delivery Technology.

About Cynviloq™

Cynviloq™ (or IG-001; a paclitaxel-loaded micellar diblock copolymer) is a
next-generation branded paclitaxel formulation currently approved and on the
market in several countries as Genexol-PM®.

About AACR

The mission of the American Association for Cancer Research is to prevent and
cure cancer. Founded in 1907, the AACR is the world's oldest and largest
professional organization dedicated to advancing cancer research. The
membership includes 33,000 laboratory, translational and clinical researchers;
health care professionals; and cancer survivors and advocates in the United
States and more than 90 other countries. The AACR marshals the full spectrum
of expertise from the cancer community to accelerate progress in the
prevention, diagnosis and treatment of cancer through high-quality scientific
and educational programs.

About Sorrento Therapeutics, Inc.

Sorrento Therapeutics, Inc. ("STI"; SRNE) is a publicly-traded,
development-stage biopharmaceutical company focused on the discovery,
development and commercialization of novel and proprietary biotherapeutics for
the treatment of a variety of disease conditions, including cancer,
inflammation, metabolic and infectious diseases. STI's objective is to
identify drug development candidates derived from its proprietary human
antibody libraries and, either independently or through partnerships, advance
selected targets into preclinical or clinical development. In 2012, STI
identified and further developed a number of potential drug product candidates
across various therapeutic areas, and STI intends to select several lead
product candidates to progress into preclinical development activities in
2013. More information is available at www.sorrentotherapeutics.com.

About IGDRASOL

IGDRASOL's lead therapeutic platform is Cynviloq™, a branded micellar
paclitaxel formulation which is free of cremophor and human serum albumin
(HSA), the excipients for Taxol® (cremophor-based paclitaxel) and
albumin-bound paclitaxel (Abraxane®), respectively. Cynviloq™ combines the
simplicity of manufacturing and preparation of Taxol® and potentially the
albumin-mediated transport of paclitaxel. IGDRASOL intends to conduct
registration trials for multiple cancer indications.

The executives of IGDRASOL are a group of pharmaceutical veterans who believe
that personalized paclitaxel nanoparticle therapy will present a paradigm
shift in the delivery of chemotherapeutic agents. To learn more about
IGDRASOL's mission, please visit its website (http://www.igdrasol.com).

Forward-Looking Statements

This press release contains forward-looking statements subject to risks and
uncertainties that could cause actual results to differ materially from those
projected. Words such as "plans," "believes," "expects," "anticipates," and
"will," and similar expressions, are intended to identify forward-looking
statements. Forward-looking statements include statements about the potential
combination of STI and IGDRASOL and the synergies and prospects for a combined
enterprise going forward; and the clinical development and commercial
potential of Cynviloq™. All such forward-looking statements are based on STI's
current beliefs and expectations, and should not be regarded as a
representation by STI that any of its plans will be achieved. Actual results
may differ materially from those set forth in this press release due to the
risks and uncertainties inherent in STI's and IGDRASOL's businesses,
including: whether STI will have sufficient cash and other resources to
exercise the option and ultimately acquire IGDRASOL; the potential that STI
and the combined company may require substantial additional funding in order
to obtain regulatory approval for and commercialize any oncology products; the
risk that delays in the regulatory approval or commercial launch of Cynviloq™
will enable competitors to further entrench existing products, or develop and
bring new competing products to market before the approval, if any, of
Cynviloq™; the scope and validity of patent protection for Cynviloq™ as well
as STI's and IGDRASOL's platform technologies, and the risk that the
development or commercialization of product candidates may infringe the
intellectual property rights of others; and additional risks set forth in
Sorrento Therapeutics' filings with the Securities and Exchange Commission.
These forward-looking statements represent Sorrento Therapeutics' judgment as
of the date of this release. You are cautioned not to place undue reliance on
these forward-looking statements, which speak only as of the date hereof. All
forward-looking statements are qualified in their entirety by this cautionary
statement and STI undertakes no obligation to revise or update this press
release to reflect events or circumstances after the date hereof. This caution
is made under the safe harbor provisions of Section 21E of the Private
Securities Litigation Reform Act of 1995.

Genexol-PM® is a registered trademark of Samyang Corporation; Abraxane® is a
registered trademark of Celgene, Inc; Taxol® is a registered trademark of
Bristol-Myers Squibb, Inc.

SOURCE Sorrento Therapeutics, Inc.

Website: http://www.sorrentotherapeutics.com
Contact: Mr. Jaisim Shah, Chief Business Officer, Sorrento Therapeutics, Inc.,
jshah@sorrentotherapeutics.com, + 1 (650) 996-2367