(RDUS) Presents RAD1901 Data at 2014 San Antonio Breast Cancer Symposium

WALTHAM, Mass., Dec. 11, 2014 — Radius Health, Inc. (Nasdaq:RDUS) announced today that it presented data from a Phase 1 clinical study on estrogen receptor engagement by the investigational drug RAD1901, a tissue-selective estrogen receptor degrader (SERD), in a poster presentation at the 2014 San Antonio Breast Cancer Symposium (SABCS).

Details of the poster presentation at SABCS are as follows:

Title: RAD1901, a novel tissue-selective estrogen receptor degrader (SERD) demonstrates estrogen receptor engagement in a phase 1 clinical study

Session/Poster: Poster Session 3; Poster OT2-1-10

Location: Halls A-B (Henry B. Gonzalez Convention Center)

Date and Time: Thursday December 11, 2014; 5:00 – 7:00 pm CST

Presenter: Gary Hattersley, PhD, Chief Scientific Officer

Despite advances in the treatment of metastatic breast cancer through modulation of estrogen receptor (ER) activity, after initial efficacy, the use of hormonal therapies is frequently followed by the development of de novo or acquired endocrine resistance. Therefore, research is being conducted on possible new agents that might be able to overcome endocrine resistance. One potential mechanism by which this might be achieved is through degradation of the estrogen receptor and thereby elimination of estrogen receptor mediated signaling.

RAD1901 is an investigational, non-steroidal small molecule that is designed to selectively bind and degrade the ER and is currently being evaluated for the potential treatment of metastatic breast cancer. In preclinical models thus far, RAD1901 has shown good tissue selectivity, does not appear to stimulate the uterine endometrium, and appears to protect against bone loss in an ovariectomy-induced osteopenia rat model. In addition, we believe that RAD1901 has the ability to cross the blood-brain barrier. In vitro, treatment of tamoxifen-sensitive and resistant human breast cancer cell lines with the investigational drug RAD1901 resulted in degradation of the ER and inhibition of both basal and estradiol-stimulated proliferation. The poster includes preclinical data indicating that increasing doses of RAD1901 potently induced tumor regression. Tamoxifen and fulvestrant were the comparator drugs in this study.

The poster also includes data from the Phase 1 study where 18F-estradiol positron emission tomography (FES-PET) was used to provide a pharmacodynamic assessment of estrogen receptor engagement/turnover. Following 6-days of daily treatment with the investigational drug RAD1901 at 200mg and 500mg doses, a complete suppression of FES-PET signal was observed, with standardized uptake values (SUV) comparable to background tissues. To date, the maximum tolerated dose of RAD1901 has not been determined.

The potential clinical significance, if any, of the data presented in the poster is currently unknown and must be evaluated further as the development program for the investigational drug RAD1901 continues.

About The Investigational Drug RAD1901

In June 2014, Radius initiated a Phase 1 MTD study in healthy volunteers with the investigational drug RAD1901, a SERD being developed for the potential treatment of metastatic breast cancer, including breast cancer brain metastases (“BCBM”). The study is designed to evaluate the tolerability, safety, and pharmacokinetics of RAD1901, and also to use 18F-fluroestradiol positron emission tomography to provide a pharmacodynamic assessment of estrogen receptor turnover following RAD1901 treatment. Levels of RAD1901 in cerebrospinal fluid samples taken from the study subjects will be measured to confirm that RAD1901 has crossed the blood brain barrier.

Radius is progressing development of the investigational drug RAD1901 for the potential treatment of metastatic breast cancer. Currently, our Phase 1b metastatic breast cancer trial is undergoing institutional review board review and after approval Radius will post the trial on www.clinicaltrials.gov. We are in discussions with the European Organization for the Research and Treatment of Cancer (EORTC) to finalize the protocol design for the initiation of a European Phase1b trial. We anticipate initiation of these trials following regulatory review and upon institutional review board approval.

Radius also is developing the investigational drug RAD1901 for potential use as a selective estrogen receptor modulator, or SERM, for the treatment of vasomotor symptoms. In a Phase 2 proof of concept study, RAD1901 at lower doses demonstrated a reduction in the frequency and severity of moderate and severe hot flashes. We anticipate initiating a Phase2b trial for the treatment of vasomotor symptoms in 2H2015.

About Radius Health

Radius is a science-driven biopharmaceutical company developing new therapeutics for patients with advanced osteoporosis as well as other serious endocrine-mediated diseases including hormone responsive cancers. Radius’ lead development candidate is the investigational drug abaloparatide (BA058) for subcutaneous injection, currently in Phase 3 development for potential use in the reduction of fracture risk in postmenopausal women with severe osteoporosis. The Radius clinical portfolio also includes an investigational abaloparatide transdermal patch for potential use in osteoporosis and the investigational drug RAD1901 for potential use in hormone driven, or hormone resistant, metastatic breast cancer, including breast cancer brain metastases. www.radiuspharm.com

Forward Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including statements regarding the potential clinical significance of the data presented in the poster presentation at SABCS, the ability of RAD1901 to cross the blood-brain barrier and the timing of the initiation of clinical trials of RAD1901.

These forward-looking statements are based on management’s current expectations. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: we have no product revenues; our need for additional funding, which may not be available; we are not currently profitable and may never become profitable; restrictions imposed on our business by our credit facility, and risks related to default on our obligations under our credit facility; risks related to raising additional capital; our limited operating history; quarterly fluctuation in our financial results; our dependence on the success of abaloparatide-SC, and our inability to ensure that abaloparatide-SC will obtain regulatory approval or be successfully commercialized; risks related to clinical trials, including having most of our products in early stage clinical trials and uncertainty that results will support our product candidate claims; the risk that adverse side effects will be identified during the development of our product candidates; product candidates for which we obtain marketing approval, if any, could be subject to restrictions or withdrawal from the market and we may be subject to penalties; failure to achieve market acceptance of our product candidates; risks related to the use of our limited resources on particular product candidates and not others; delays in enrollment of patients in our clinical trials, which could delay or prevent regulatory approvals; the dependence of our drug development program upon third-parties who are outside our control; the risk that a regulatory or government official will determine that third-parties with a financial interest in the outcome of the Phase 3 study of abaloparatide-SC affected the reliability of the data from the study; our reliance on third parties to formulate and manufacture our product candidates; failure to establish additional collaborations; our lack of experience selling, marketing and distributing products and our lack of internal capability to do so; failure to compete successfully against other drug companies; developments by competitors may render our products or technologies obsolete or non-competitive; risks related to the fact that our drugs may sell for inadequate prices or patients may be unable to obtain adequate reimbursement; effects of product liability lawsuits on commercialization of our products; failure to comply with obligations of our intellectual property licenses; failure to protect our intellectual property or failure to secure necessary intellectual property related to abaloparatide-SC, abaloparatide-TD, RAD-1901 and/or RAD-140; our or our licensors’ inability to obtain and maintain patent protection for technology and products; risks related to our compliance with patent application requirements; failure to protect the confidentiality of our trade secrets; risks related to our infringement of third parties’ rights; risks related to employees’ disclosure of former employers’ trade secrets; risks associated with intellectual property litigation, including expending substantial resources and distracting personnel from their normal responsibilities; risks associated with healthcare reform; our failure to comply with healthcare laws and regulations; our exposure to claims associated with the use of hazardous materials and chemicals; inability to successfully manage our growth; risks relating to business combinations and acquisitions; our reliance on key executive officers and advisors; our inability to hire additional qualified personnel; volatility in the price of our common stock; capital appreciation is the only source of gain for our common stock; risks related to increased costs and compliance initiatives associated with operating as a public company; our directors, executive officers and principal stockholders have substantial control over us and could delay or prevent a change in control; future sales of our common stock could depress the price of our common stock; inaccurate or unfavorable information about us could cause the price of our common stock to decline; provisions in our charter documents and Delaware law could discourage takeover attempts; and our ability to use our net operating loss carryforwards and certain other tax attributes may be limited. These and other important factors discussed under the caption “Risk Factors” in our Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission, or SEC, on November 10, 2014, and our other reports filed with the SEC could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this press release.

CONTACT: Investor Relations
         Barbara Ryan
         FTI Consulting
         Managing Director
         212-850-5679
         Barbara.Ryan@fticonsulting.com

         Media Relations
         Kimberly Ha
         FTI Consulting
         Senior Director
         212-850-5612
         Kimberly.Ha@fticonsulting.com