Safe harbor

This presentation and our remarks based upon it, including responses to questions made during and following the presentation, may include forward-looking statements. Such statements are subject to the risks and uncertainties we discuss in detail in our reports filed with the Securities & Exchange Commission, including in our quarterly report on Form 10-Q filed November 8, 2012. We expressly disclaim any obligation to release publicly any updates to forward-looking statements made during the course of this presentation.

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Two late stage clinical programs

• Enobosarm (Ostarine; GTx-024), a SARM, for the prevention and treatment of muscle wasting in patients with non-small cell lung cancer: Eight clinical trials completed to date involving approximately 600

subjects

Granted fast track status January 2013

Enrollment completed 4Q 2012 for two pivotal Phase III clinical trials with approximately 650 non-small cell lung cancer (NSCLC) patients – top line results expected summer 2013

DSMB reviewed safety data in October 2012 and agreed trial could continue as planned

• Capesaris (GTx-758), an oral selective ER alpha agonist, for combination primary ADT & secondary hormonal treatment of advanced prostate cancer: Eight clinical trials conducted to date involving approximately 500

subjects

Phase II 712 clinical trial evaluating Capesaris® (GTx-758) for secondary hormonal treatment in men with metastatic castration resistant prostate cancer currently enrolling

Selective Androgen Receptor Modulator (SARM)for the prevention and treatment of muscle wasting

in patients with lung cancer

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• At diagnosis, nearly 50% of advanced NSCLC patients have severe muscle loss and approximately 70% of NSCLC patients will lose muscle 88% have lower body functional limitations including the ability to

climb stairs, lift and carry 10 lbs, walk ¼ mile, and stoop, crouch or kneel

• Performance status is a predictor of a patient’s ability to tolerate chemotherapy, and poor performance status is a primary reason patients are not offered treatment

Performance status also predicts the likelihood of hospitalization, ability to maintain independence, and survival

Muscle wasting is an important cancer related symptom in patients with advanced NSCLC

Baracos VE, et al. Am J Clin Nutr. 2010 Apr;91(4):1133S-1137S. Baracos VE. 2011 data on file. Bruera E. BMJ. 1997;315(7117)1219-22. Schootman M, et al. Cancer. 2009 Nov 15;115(22):5329-38. Braithwaite D, et al. J Natl Cancer Inst. 2010;102(191):1468-77. Prado CMM, et al. The Lancet Oncology 2008;9(7):629-35.

Phase IIb clinical trial in cancer patients:Enobosarm increased lean body mass & improved physical function in NSCLC

Subset analysis: 61 NSCLC patients•Mean weight loss at entry was 9.7%•Enobosarm treated patients had a mean 18% improvement in stair climb power from baseline and 1.1 kg improvement in LBM •No statistically significant improvements in physical function or LBM in placebo group

• Reported incidence of tumor progression similar across groups

• The most common AEs were fatigue, anemia, nausea and diarrhea

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Endpoint Placebo Enobosarm

Physical Function 19% 42%

Lean Body Mass 24% 42%

Ad Hoc Phase IIb Responders Analysis – NSCLC*Ad Hoc Phase IIb Responders Analysis – NSCLC*

Safety- NSCLCSafety- NSCLC

*Based on ITT including 30% drop out rate

International pivotal Phase III clinical trials: POWER 1 and 2

Input from FDA, MHRA (England) and MPA (Sweden) on Phase III clinical development plans and Fast Track granted 1/13

150 patients

150 patients

150 patients

Other endpoints•QoL – FAACT, FACIT fatigue scales•Healthcare resource

utilization•Adherence to chemo plans•Tolerance to chemo

Co-primary endpoints•Lean body mass •Physical function SCP @ 3 months

Placebo

Enobosarm3 mg

Enobosarm 3 mg

Secondary endpoints•Durability of effect @ 5 months•Overall survival

Placebo

platinum + taxane

150 patients

platinum + non taxane

Indication: Prevention and treatment of muscle loss in patients with NSCLC• Stage III/IV NSCLC patients initiating 1st line chemotherapy

• Co-primary endpoints (responders analysis): (1) no loss of lean body mass (LBM) by DEXA; (2) at least 10% improvement in Stair Climb Power (SCP)

• Each endpoint α=0.05, power >93%

• Assumes 30% drop out rate by 3 months

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EnobosarmAnticipated clinical development plan

Phase III-POWER 1Enobosarm 3 mg vs placebo in 300 pts

with NSCLC receiving platinum + taxane chemotherapy (5 month study)

Phase III-POWER 2Enobosarm 3 mg vs placebo in 300 pts

with NSCLC receiving platinum + non taxane chemotherapy (5 month study)

NDA

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First patient enrolled

Last patient out

EnobosarmLarge market opportunity

United States

Source: Datamonitor 2011; projected market size in 2012, US and EU Qualitative market research

Stage III-IV NSCLC is the majority of NSCLC diagnosed and, based on perceptions of oncologists, at least 50% of these patients have muscle wasting

hyperK+ Rates

NSCLC207 K

Stage III-IVNSCLC

161 K (78%)

Muscle Wasting 81K (~50%)

5 EU

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hyperK+ Rates

NSCLC186 K

Stage III-IVNSCLC

148 K (79%)

Muscle Wasting 74K (~50%)

EnobosarmLarge market opportunity- US Payors’ perspective*

• Improvement in physical function and increase in muscle mass were considered the

two most favorable clinical attributes of enobosarm

• All economic endpoints being evaluated are acceptable by the majority of Payors

Hospitalizations, ER visits, mobility devices, home health services, and hospice

• 80% of Payors would cover enobosarm with or without restriction

• At a monthly WAC of $1500 - $3000 the majority of Payors would cover enobosarm as a Tier 3 with a prior authorization

• Currently, several drugs treating cancer related symptoms are priced between $30 and $50 per day

Xgeva (CTIBL and SRE) $55 per day

Zometa (CTIBL and SRE) $40 per day

Neulasta (neutropenia) $5600 per dose

• GTx estimates muscle wasting indication in patients with NSCLCcould be a $750 million opportunity in US alone

10*Based on US Managed Healthcare Landscape and Assessment of Enobosarm, Managed Solutions, LLC April 2012

EnobosarmIntellectual property

• 79 enobosarm composition of matter and method of use patent applications issued, approved, or pending in U.S. and rest of world with expiration dates in 2024. Includes issued composition of matter and method patents in US and Japan

• As a new chemical entity, issued patents should be eligible for patent term extension of up to 5 years (2029)

• GTx has 350 patents issued, approved or pending worldwide for all SARMs including enobosarm

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Selective ERα agonist for the treatment of advanced prostate cancer

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HormoneSensitive

FirstSecondaryHormone Tx

CapesarisEnzalutamide

Second Secondary Hormone Tx

CapesarisEnzalutamide

ThirdSecondary Hormone Tx

Abiraterone + PrednisoneCapesaris

Chemotherapy

DocetaxelPostChemotherapy

EnzalutamideAbiraterone/PrednisoneCabazitaxel

Castration Resistant Prostate Cancer (CRPC)

Advanced Prostate Cancer

750,000patients

80,000patients

36,000patients Market

Evolving treatment options for advanced prostate cancer

=approved

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Multiple potential mechanisms of action for a selective ERα agonist to treat prostate cancer

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Higher SHBG reduces available free (unbound) T

Adapted from Dunn JF et al. (1981) J Clin Endo and Metabolism, 53:58-68

Phase II studies in men with advanced prostate cancer confirms the mechanism of action*• Phase II open label loading dose finding 705 clinical study in

advanced prostate cancer comparing1500mg BID and 1000mg BID loading doses followed by 1000mg or 2000mg maintenance doses (n=55)

• Castration rate greater than 90% for both arms• Capesaris increased SHBG and decreased free T

• Phase II open label maintenance dose finding 710 clinical study in advanced prostate cancer comparing Lupron, Capesaris 1000mg PO qd and Capesaris 2000mg PO qd (n=164) 2000mg Capesaris and Lupron arms

• Maintained castration by Kaplan-Meier estimates >95.5%• Similar testosterone escapes• Capesaris increased SHBG and decreased free T• Improvement in hot flashes, bone turnover markers and insulin

resistance

• Safety- VTE incidence rate increased for Capesaris16*Studies terminated prior to completion

Phase II, open label, 712 clinical study of secondary hormonal treatment in men with metastatic CRPCstarted 3Q 2012

Subjects•mCRPC•Maintain ADT

Primary Endpoint:•Serum PSA response

Secondary Endpoints:•PSA progression•Progression free survival•Free T/SHBG•Adrenal (DHEA&DHEAS)•Estrogen deficiency side effects•SRE

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Day 90

25 patients

25 patients

25 patients

GTx-758 250 mg

GTx-758 500 mg

GTx-758 125 mg

Day 0

30 d

30 d

Capesaris Steering Committee

• Medical oncology Evan Yu* (U Washington) Johann DeBono* (Royal Marsden) Dan Petrylak* (Columbia/ Yale) Chuck Ryan* (UCSF) Phil Kantoff* (Dana Farber Harvard) Thomas Flaig* (U Colorado)

• Urology Badri Konety (U Minnesota)

• Advocacy group Tom Kirk (Us TOO)

* Confirmed participation18

Phase IIb705 clinical study

Maintenance dose finding

Phase II710 clinical study

Loading dose finding

CapesarisAnticipated clinical development plan

Phase II712 clinical study

Secondary hormonal therapy in mCRPC patients (lower doses)*

Phase II707 clinical study

Secondary hormonal therapy in CRPC patients

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*Estimated based on projected enrollment

CapesarisIntellectual Property

• Approximately 43 composition of matter and method of use patent applications and patents, which are either issued, allowed or pending in the US and rest of world with expiration dates of January 2029 in the US (issued) and November 2026 in the ROW

• As a chemical entity, issued US patent should be eligible for additional patent term extension of up to 5 years (for a maximum term of November 2034), as may be determined following FDA approval of Capesaris

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Financial summary

• Shares outstanding: 62.8 M

• Cash, cash equivalents and short-term investments at December 31, 2012: $56.1M

• No debt, no warrants

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