NEW YORK (AP) ¿ Medidata Solutions Inc., a maker of software and services for clinical development of drugs and medical devices, said Friday it plans a public offering of 4.5 million shares of its common stock. Medidata, which filed a registration statement with the Securities and Exchange Commission, said the shares are being offered by certain stockholders of the company, including funds affiliated with Insight Venture Partners. Medidata will not receive any proceeds from the offering, it said. Shares of the New York-based company fell $1.10, or 6.2 percent, to close at $16.68. The offering announcement comes about five months after Medidata's initial public offering. A regulatory filing listed nearly 22.7 million shares outstanding as of Nov. 9. If underwriters sell more than 4.5 million shares in the offering, the selling stockholders intend to grant the underwriters an option to buy up to 675,000 shares of common stock within 30 days. Citigroup Global Markets and Credit Suisse Securities (USA) are acting as joint bookrunning managers for the proposed offering. Jefferies & Co. and Needham & Co. are acting as co-managers.