Manhattan Pharmaceuticals Announces Completion of Enrollment in Phase 2a Study of...

Manhattan Pharmaceuticals Announces Completion of Enrollment in Phase 2a Study
of Topical PTH (1-34) for Psoriasis

NEW YORK, April 10, 2008 (PRIME NEWSWIRE) -- Manhattan Pharmaceuticals, Inc.
(OTCBB:MHAN) announced today that it has completed patient enrollment in its
ongoing Phase 2a clinical study of Topical PTH (1-34). This randomized,
double-blind, vehicle-controlled, parallel group study is designed to evaluate
safety and preliminary efficacy of Topical PTH (1-34) for the treatment of
psoriasis. The study randomized 61 patients into three treatment groups (two
dose levels of Topical PTH (1-34) and one vehicle only group) for an 8-week
treatment period at four U.S. clinical trial sites. The vehicle used in this
study is the topical product without the active ingredient, PTH (1-34). The
company expects to announce the results of this study in summer 2008.

"We are pleased to have completed enrollment in this Phase 2a study on
schedule," stated Douglas Abel, president and chief executive officer of
Manhattan Pharmaceuticals, Inc. "We look forward to completing the study and
announcing results later this year."

A previously completed Phase 1/2, double-blind, placebo-controlled study was
conducted under a physician investigational new drug (IND) application at Boston
University Medical Center with Topical PTH (1-34) in patients with psoriasis. A
67% global improvement was observed in the trial patients with 60% of
participants experiencing a complete clearing of their psoriasis lesions and 85%
experiencing at least partial clearing. In this study, Topical PTH (1-34)
treatment was well tolerated with no adverse effects reported.

About Topical PTH (1-34)

It is believed that PTH (1-34) is an agonist that mimics a natural protein
responsible for regulating the growth of skin cells. The presence of this
natural protein, PTHrp, is significantly reduced in the skin of psoriasis
patients leading to skin cell hyperproliferation, poor differentiation of skin
cells, and ultimately, the accumulation of dry thick patches of skin (plaques).
Acting in place of the absent PTHrp, it is also believed that PTH (1-34) is able
to restore skin cells' normal rate of development, migration and turnover,
reducing cell accumulation and the formation of plaques.

About Psoriasis

Psoriasis is a common, chronic, immune-mediated disease that results in the
over-production of skin cells. In healthy skin, immature skin cells migrate from
the lowest layer of the epidermis to the skin's surface over a period of 28-30
days. In psoriasis, these cells reproduce at an extremely accelerated rate and
advance to the surface in only 7 days. This results in a build up of excess,
poorly differentiated skin cells that accumulate in dry, thick patches known as
plaques. These plaques can appear anywhere on the body resulting in skin
irritation and disability.

According to the National Psoriasis Foundation nearly 2% of the worldwide
population, including approximately 4.5 million Americans, suffers from
psoriasis. In the U.S., psoriasis patients are responsible for nearly 2.4
million visits to dermatologists each year at an annual cost of nearly $3
billion. Manhattan Pharmaceuticals estimates the U.S. topical psoriasis
therapeutics market to be approximately $400-500 million, with the market
throughout the rest of the world in the same range.

About Manhattan Pharmaceuticals, Inc.

Manhattan Pharmaceuticals, Inc. is a specialty pharmaceutical company that
acquires and develops novel, high-value drug candidates primarily for the
treatment of dermatologic and immune disorders. With a pipeline consisting of
four clinical stage product candidates, the company is currently developing
Hedrin(tm), a novel, non-insecticide treatment for pediculosis (head lice);
Topical PTH (1-34) for the treatment of psoriasis; Altoderm(tm) (topical
cromolyn sodium) for the treatment of pruritus associated with dermatologic
conditions including atopic dermatitis; and Altolyn(tm) (oral tablet cromolyn
sodium) for the treatment of mastocytosis. (http://www.manhattanpharma.com)

Note Regarding Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the
Private Securities Litigation Reform Act of 1995, including, among others, those
relating to our Phase 2a study of Topical PTH (1-34) for psoriasis. Such
statements involve risks and uncertainties that could cause Manhattan
Pharmaceuticals, Inc.'s actual results to differ materially from the anticipated
results and expectations expressed in these forward-looking statements. These
statements are often, but not always, made through the use of words or phrases
such as "anticipates," "expects," "plans," "believes," "intends," "will," and
similar words or phrases. These statements are based on Manhattan
Pharmaceuticals, Inc.'s current expectations, forecasts and assumptions, which
are subject to risks and uncertainties, which could cause actual outcomes and
results to differ materially from these statements. Among other things, there
can be no assurances that Manhattan Pharmaceuticals, Inc.'s development efforts
relating to its PTH (1-34), Hedrin(tm), Altoderm(tm), or Altolyn(tm) product
candidates, or any future product candidates, will be successful, or that
Manhattan Pharmaceuticals, Inc. will be able to out-license its discontinued
programs to other companies on terms acceptable to Manhattan Pharmaceuticals,
Inc. or at all. Other risks that may affect forward-looking information
contained in this press release include, without limitation, the company's
extremely limited capital resources, the possibility of being unable to obtain
regulatory approval of Manhattan Pharmaceuticals, Inc.'s product candidates, the
risk that the results of clinical trials may not support the company's claims,
the risk that the company's product candidates may not achieve market acceptance
in North America or elsewhere, the company's reliance on third-party researchers
to develop its product candidates, availability of patent protection, the risk
that sufficient capital may not be available to develop and commercialize the
company's product candidates, the company's lack of experience in developing and
commercializing pharmaceutical products. Additional risks are described in the
company's filings with the Securities and Exchange Commission, including its
Annual Report on Form 10-K for the year ended December 31, 2007. Manhattan
Pharmaceuticals, Inc. assumes no obligation to update the information contained
in this press release, whether as a result of new information, future events or
otherwise.

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CONTACT: Manhattan Pharmaceuticals, Inc.
Michelle Carroll, Investor Relations
(212) 582-3950