<PAGE>




EXHIBIT 99.33



Contact:  Jerry B. Hook, Ph.D.                Martin Rose, M.D., J.D.

          Chairman, President & CEO           Vice President, Clinical &
                                              Regulatory Affairs

          Sparta Pharmaceuticals, Inc.        Sparta Pharmaceuticals, Inc.

          (215) 442-1700, Ext. 205            (215) 442-1700, Ext. 219



http://www.spartapharma.com





FOR IMMEDIATE RELEASE



             Spartaject(TM) Busulfan Phase I Trial in Patients with

         Neoplastic Meningitis Begins at Duke University Medical Center



Horsham, PA, June 11, 1998, Sparta Pharmaceuticals, Inc. (NASDAQ: SPTA, SPTAU,
SPTAW, SPTAZ, and SPTAL) announces the commencement of a Phase I trial using
SpartajectTM busulfan intrathecally for the treatment of neoplastic meningitis
in adults and children. The study is being performed under an
investigator-sponsored IND held by Henry Friedman, M.D., Professor of Pediatrics
and Chief of the Division of Pediatric Neuro-Oncology at Duke University Medical
Center, who is the principal investigator. Dr. Friedman is an internationally
recognized neuro-oncologist with extensive experience in the investigation of
drugs for the treatment of tumors of the central nervous system, including drugs
for neoplastic meningitis.



Neoplastic meningitis refers to the multifocal seeding of metastatic malignant
cells along the leptomeninges of the central nervous system. The leptomeninges
line the subarachnoid space, in which the cerebrospinal fluid (CSF) flows.
Neoplastic meningitis characteristically carries a dismal prognosis, with median
survival generally reported as being a few months despite the best available
current treatments. New therapeutic approaches are badly needed.



Neoplastic meningitis has been reported to complicate the clinical course of
about 8% of patients with metastatic cancer. The prevalence of neoplastic
meningitis in an autopsy series of cancer patients has been as high as 30%. Lung
cancer, breast cancer, and melanoma are the solid tumors that are most often
associated with neoplastic meningitis. Primary brain tumors, lymphomas, and
leukemias are also common causes of neoplastic meningitis.

<PAGE>


In Dr. Friedman's study, escalating doses of Spartaject(TM) busulfan will be
injected intrathecally, i.e., into the CSF, using either a needle inserted
through the skin or an implanted reservoir. The goal of the study is to
demonstrate the maximum tolerated dose of Spartaject(TM) busulfan in this
setting, to characterize the pharmacokinetics of busulfan in the CSF and blood
after intrathecal injection, and to assess the response of the patients'
neoplastic meningitis to therapy with Spartaject(TM) busulfan. Dr. Friedman
previously demonstrated that, compared to no treatment, intrathecal therapy with
Spartaject(TM) busulfan significantly prolonged life in animals with models of
neoplastic meningitis.



Busulfan, an effective anticancer agent that is approved in the U.S. for chronic
myelogenous leukemia, is insoluble in water and required special preparation to
be injected. Sparta's Spartaject(TM) Busulfan , which contains no potentially
toxic solubilizing agents, will be used in this trial.



Sparta recently announced completion of the patient treatment phase of its Phase
I clinical trial in adults of the use of intravenous SpartajectTM busulfan in
patients being prepared for bone marrow transplantation, and the FDA's
concurrence with the Company's plans for pivotal trials using Spartaject(TM)
busulfan in adults and children undergoing this procedure.



This press release contains certain forward-looking statements within the
meaning of the "safe harbor" provisions of the Private Securities Litigation
Reform Act of 1995. Such statements are made based on management's current
expectations and beliefs, and actual results may vary from those currently
anticipated based upon a number of factors, including uncertainties inherent in
the drug development process, including the success and timing of clinical
trials and the receipt of necessary approvals by the FDA. The Company undertakes
no obligation to release publicly any revisions which may be made to reflect
events or circumstances after the date hereof.



Sparta is a development stage pharmaceutical company engaged in the business of
acquiring rights to, and developing for commercialization, technologies and
drugs for the treatment of a number of life threatening diseases including
cancer, cardiovascular disorders, chronic metabolic diseases and inflammation.
The Company has focused on acquiring compounds that have been previously tested
in humans and animals and technologies that may improve the delivery or
effectiveness of previously tested, and in some cases marketed, drugs. Sparta's
portfolio of compounds in clinical trials includes four potential oncology
products and one for the treatment of Type II diabetes. The Company's portfolio
also includes emerging platform technologies in recombinant and small molecule
protease inhibitors.

                                      # # #