After six years of honing its target markets, Rexahn Pharmaceuticals Inc. has hired a financial ‘‘megaphone” to get its story out to small and mid-cap investors.

‘‘The company is growing and we are poised to achieve our set goal of 2015, moving every research into that direction,” said CEO Chang H. Ahn, a former researcher with the Food and Drug Administration.

Rexahn has hired Catalyst Financial Resources LLC of Portland, Ore., to help foster that growth.

‘‘We stand up for the little guy,” said Catalyst’s analyst Mark Robins. ‘‘We heard their story and they are a company we can help.”

Catalyst acts as a megaphone for promising startups facing a tough funding climate to reach out and touch 200 to 300 micro-cap investors, he said.

Rexahn, which has 15 employees, has three phase 2, or mid-stage, clinical trials planned for 2007. The company is developing highly targeted drugs designed to treat cancer, central nervous system disorders and sexual dysfunction with a minimum of toxicity, Ahn said.

Rexahn’s recent expansion into nervous system treatments holds the most hope for financial success, Robins said, though Ahn remains dedicated to finding new cancer treatments.

Ahn, a 25-year-scientist turned businessman, has tried to find answers to treating cancer since his older sister died of stomach cancer in 1990. He was reviewing cancer and other drugs for the Food and Drug Administration at that time.

‘‘I thought I knew a lot about cancer,” Ahn said. But when he was faced with cancer in a relative, he could not help her.

‘‘The drugs were really bad,” he said. ‘‘I recognized our current therapeutics were not good for the patient. More innovative, less toxic drugs were needed.”

Rexahn’s motto is ‘‘saving lives through innovation.”

After his sister died, Ahn left the FDA to study molecular biology of cancer cells at the National Cancer Institute in Bethesda. He focused on molecules that increase the survival and multiplication of tumor cells.

‘‘Because of my background in cancer drug reviews I recognized that these could be one of the most important targets for cancer therapy,” he said.

At Rexahn, Ahn is still driven to develop cancer drugs. But, through eye-opening meetings with ‘‘biotech gurus” in the region in 2002, he said, he was disappointed to learn that his only choice for business success was very rapid growth of Rexahn.

‘‘I told him that cash is king and keep burn rates low because it is easy to be lulled into a false sense of security,” said Bruce Robertson, formerly with Toucan Capital Corp. in Bethesda and now managing director of H.I.G. Ventures in Atlanta.

Another letdown, Ahn said, was realizing that marketing cancer drugs would not lead to financial success.

There are more than 400 cancer drugs under development and the market value for new ones is limited, according to the FDA.

‘‘The reality is that you spend all your time as a scientist, then you have a eureka moment of understanding the medical significance of something,” Robins said.

‘‘But then you are up against expenses of the FDA [clinical trial approval] process and getting the medical field to understand what you have and make it remunerative,” he said.

Robertson told Ahn to network like crazy.

‘‘He is good at that,” Robertson said. ‘‘Business is relationship driven.”

In 2005, Ahn found new hope for revenues by applying his work in signal-disrupting drugs to neurology and potential multibillion-dollar markets for Parkinson’s disease and depression.

‘‘I looked at different therapeutic fields and found that the brain areas are totally open. Schizophrenia, Parkinson’s, depression — nobody knows what causes them,” Ahn said. ‘‘For guys like me coming from signal transduction work in cancer, it is a bonanza.”

One of Rexahn’s promising drugs, RX-10100 for depression, may also be a unique treatment for premature ejaculation. Animal studies showed the drug acts upon serotonin and dopamine, which are key neurotransmitters in the brain, for both sexual dysfunction and anxiety.

Ahn predicts a market of $1 billion for cancer drugs and at least $2 billion for the depression and anxiety drugs.

‘‘We are excited about the premature ejaculation area,” Robins said. ‘‘There is more interest in this than with Viagra and Levitra. It’s a bigger market.”

Meanwhile, the phase 2 trial of Rexahn’s RX-0201this year will focus on patients with advanced-stage kidney cancer known as renal cell carcinoma. It will then be tested on pancreatic and stomach cancers.

The FDA granted Rexahn orphan drug status for RX-0201 in 2005 to speed up its development.

This month, Rexahn won a $215,408 grant from the Maryland Industrial Partnerships Program to develop nano-polymers for targeted delivery of anticancer drugs in cooperation with the Center for Nanomedicine & Cellular Delivery of the University of Maryland, Baltimore.

Robins said Catalyst will begin to include the company in investor conferences, institutional targeting and equity research coverage, to help promote Rexahn’s visibility in the financial marketplace.

‘‘They will facilitate some face-to-face meetings and organize conferences. We would be among the participants there to start to get analysts’ coverage for us,” said Tiffany L. Parker, Rexahn’s director of communications and investor relations.

Rexahn went public in 2005 through a reverse merger with a public company, Corporate Roadshow.com Inc. of New York. Rexahn reported a loss of $6.1 million for the nine months ended Sept. 30, compared with a loss of $3.2 million for the same period in 2005.