Forward-Looking Information

This Management's Discussion and Analysis of Financial Condition and Results of Operations contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended, and Section 27A of the Securities Act of 1933, as amended and should be read in conjunction with the "Risk Factors" section of this Form 10-Q. All statements contained in this Form 10-Q other than statements of historical fact are forward-looking statements. When used in this report or elsewhere by management from time to time, the words "believe," "anticipate," "intend," "plan," "estimate," "expect," and similar expressions are forward-looking statements. Such forward-looking statements are based on current expectations, but the absence of these words does not necessarily mean that a statement is not forward-looking. Forward-looking statements may include, but are not limited to, statements about:

• the progress and timing of our research, development and clinical programs and the timing of regulatory activities;

• the timing of the market introduction of CORLUXฎand future product candidates, including CORT 108297;

• estimates of the dates by which we expect to report results of our clinical trials and the anticipated results of these trials;

• our ability to market, commercialize and achieve market acceptance for CORLUX or other future product candidates;

• uncertainties associated with obtaining and enforcing patents;

• our estimates for future performance; and

• our estimates regarding our capital requirements and our needs for, and ability to obtain, additional financing.

Forward-looking statements are not guarantees of future performance and involve risks and uncertainties. Actual events or results may differ materially from those discussed in the forward-looking statements as a result of various factors. For a more detailed discussion of such forward-looking statements and the potential risks and uncertainties that may impact upon their accuracy, see "Risk Factors" and the "Overview" and "Liquidity and Capital Resources" sections of this "Management's Discussion and Analysis of Financial Condition and Results of Operations" included in this Form 10-Q. These forward-looking statements reflect our view only as of the date of this report. Except as required by law, we undertake no obligations to update any forward looking statements. Accordingly, you should also carefully consider the factors set forth in other reports or documents that we file from time to time with the Securities and Exchange Commission.

Overview

We are a pharmaceutical company engaged in the development of medications for the treatment of severe psychiatric and metabolic diseases. Since our inception in May 1998, we have been developing our lead product, CORLUX, a glucocorticoid receptor II, or GR-II, antagonist.

Psychotic Depression

Our lead program is for the development of CORLUX for the treatment of the psychotic features of psychotic major depression, under an exclusive patent license from Stanford University. Psychotic major depression, or PMD, will hereinafter be referred to as psychotic depression. The United States Food and Drug Administration, or FDA, has granted "fast track" status to evaluate the safety and efficacy of CORLUX for the treatment of the psychotic features of psychotic depression. Between August 2006 and March 2007 we announced the results of our initial three Phase 3 trials in which CORLUX was evaluated for treating the psychotic features of psychotic depression.

We reported the results of Study 06, the last of the three Phase 3 trials during 2007. These results indicated that this study did not achieve statistical significance with respect to the primary endpoint, 50% improvement in the Brief Psychiatric Rating Scale Positive Symptom Subscale, or BPRS PSS, at Day 7 and at Day 56. However, there was a statistically significant correlation between the plasma levels of CORLUX and clinical outcome. Patients whose plasma levels rose above a predetermined threshold statistically separated from both those patients whose plasma levels were below the threshold and those patients who received placebo. In particular, those patients in Study 06 who achieved a predetermined level of 1661 nanograms of CORLUX per milliliter of plasma separated from the placebo group with statistical significance on the primary endpoint. Conversely, at substantially lower plasma levels, there was no distinguishable difference in response rates between

patients who received CORLUX and those receiving placebo. This study confirms a similar finding in Study 07 that at higher plasma levels the drug candidate is able to demonstrate desired clinical effects. Further, the incidence of serious adverse events did not differ between placebo and any of the three CORLUX dose groups.

Data aggregated from our major efficacy studies of similar design, Study 03, Study 06, Study 07 and Study 09, (724 observed cases) indicate that the patients who received CORLUX separated from the placebo group with statistical significance for the endpoint, 50% improvement in the BPRS PSS at Day 7 and at Day 56. In addition, using the same endpoint, patients who achieved a drug level in their plasma that was greater than the 1661 nanograms per milliliter threshold mentioned above, statistically separated from both those patients whose plasma levels were below this threshold and those patients who received placebo.

We believe that the confirmation of a correlation between drug concentration and clinical response, as well as other observations from Study 06 and our other two completed Phase 3 clinical trials, serves as a strong basis for our current Phase 3 study (Study 14), which commenced enrollment in March of 2008. The protocol for this trial incorporates what we have learned from the three completed trials to address the established relationship between increased drug plasma levels and clinical response and attempts to decrease the random variability observed in the results of the psychometric instruments used to measure efficacy. In Study 06, Corcept prospectively tested and confirmed that patients whose plasma levels rose above a predetermined threshold statistically separated from both those patients whose plasma levels were below the threshold and those patients who received placebo; this threshold was established from data produced in earlier studies. As expected, patients who took 1200 mg of CORLUX developed higher drug plasma levels than patients who received lower doses. Further, there was no discernable difference in the incidence of adverse events between placebo and any of the three CORLUX dose groups in Study 06. Based on this information, we are using a CORLUX dose of 1200 mg once per day for seven days in Study 14. We believe that this change in dose, as well as other modifications to the protocol, should allow us to demonstrate the efficacy of CORLUX in the treatment of the psychotic symptoms of psychotic depression. We currently anticipate that we will have a sufficient number of patients enrolled in this study by late 2009 to enable the independent data safety monitoring board to perform an interim analysis of the safety and top-line efficacy results from the first half of the study.

Cushing's Syndrome

In July 2007, we received Orphan Drug Designation from the FDA for CORLUX for the treatment of Cushing's Syndrome. Cushing's Syndrome is a disorder caused by prolonged exposure of the body's tissues to high levels of the hormone cortisol. Sometimes called "hypercortisolism," it is relatively rare and most commonly affects adults aged 20 to 50. An estimated 10 to 15 of every one million people are newly diagnosed each year.

Orphan Drug Designation is a special status granted by the FDA to encourage the development of treatments for diseases or conditions that affect fewer than 200,000 patients in the United States. Drugs that receive Orphan Drug Designation obtain seven years of marketing exclusivity from the date of drug approval as well as tax credits for clinical trial costs, marketing application filing fee waivers and assistance from the FDA in the drug development process.

The Investigational New Drug application (IND) for the evaluation of CORLUX for the treatment of Cushing's Syndrome was opened in September 2007. The FDA has indicated that a single study may provide a reasonable basis for the submission of a New Drug Application (NDA) for this indication. This trial was opened for enrollment in December 2007.

Management of Weight Gain induced by Antipsychotics

In 2005, we published the results of studies in rats that demonstrated that CORLUX, a potent GR-II (cortisol) receptor antagonist, both reduced the weight gain associated with the ongoing use of olanzapine and mitigated the weight gain associated with the initiation of treatment with olanzapine.

During 2007 we announced the positive results of our proof-of-concept study evaluating the ability of CORLUX to mitigate weight gain associated with the use of Zyprexa. This study in healthy male volunteers was initiated during the first quarter of 2006. The results show a statistically significant reduction in weight and waist circumference gain in those subjects who took Zyprexa plus CORLUX compared to those who took Zyprexa alone. Eli Lilly and Company, or Lilly, provided Zyprexa and financial support for this study.

The combination of Zyprexa and CORLUX is not approved for any indication. The purpose of this study was to explore the hypothesis that GR-II antagonists would mitigate weight gain associated with atypical antipsychotic medications. The group of medications known as atypical antipsychotics, including Zyprexa, Risperdal, Clozaril and Seroquel, are widely used to treat schizophrenia and bipolar disorder. All medications in this group are associated with treatment emergent weight gain of varying degrees and carry a warning label relating to treatment emergent hyperglycemia and diabetes mellitus.

During 2008, we have been preparing for additional studies in humans with CORLUX to mitigate the weight gain induced by other atypical antipsychotic medications. The first of these studies commenced during the fourth quarter of 2008.

Research

In early 2003, we initiated a discovery research program to identify and patent selective GR-II antagonists to develop a pipeline of products for proprietary use. Three distinct series of GR-II antagonists were identified. Composition of matter patents on two of the series have been allowed in Europe, while substantive examination in the corresponding United States applications has not yet begun. United States and European applications have been filed for composition of matter patents in the third series, and are currently undergoing substantive examination. These compounds appear to be as potent as our lead product CORLUX in blocking cortisol but, unlike CORLUX, they do not appear to block the PR (progesterone), ER (estrogen), AR (androgen) or GR-I (mineralocorticoid) receptors.

We have signed agreements with our contract research scientists to continue our discovery research activities on new compounds through December 2008.

New Chemical Entity - CORT 108297

In 2007, we commenced a human microdosing study of one of our newly identified selective GR-II antagonists, CORT 108297, with Xceleron Limited utilizing their Accelerator Mass Spectrometry technology. In this microdosing study, we evaluated CORT 108297, a compound which develops particularly high plasma and brain concentrations in an animal model. On May 1, 2008, we announced the results from this study, which demonstrated that CORT 108297 was extremely well absorbed, demonstrated good bioavailability and had a half-life that appears compatible with once-a-day oral dosing. In addition, further pharmacokinetic testing of CORT 108297 in a rat model indicated that a ten-fold increase in oral dose (5 milligrams per kilograms to 50 milligrams per kilograms) led to a proportional increase in the amount of compound detected in plasma.

In September 2008, we signed a second agreement with Lilly, under which Lilly agreed to provide funding and provide olanzapine for two studies to test the effectiveness of CORT 108297 in rat models of olanzapine induced weight gain. The first of these studies commenced during the third quarter of 2008.

General

Our activities to date have included:

• product development;

• designing, funding and overseeing clinical trials;

• regulatory affairs; and

• intellectual property prosecution and expansion.

Historically, we have financed our operations and internal growth primarily through private placements of our preferred and common stock and the public sale of common stock rather than through collaborative or partnership agreements. Therefore, we have no research funding or collaborative payments payable to us, except for the limited revenue under the agreements with Lilly discussed above.

We are in the development stage and have incurred significant losses since our inception. We have not generated any revenue through September 2008 other than the revenue under the collaboration agreements with Lilly, and do not expect to generate significant revenue for the foreseeable future. As of September 30, 2008, we had an accumulated deficit of $123.9 million. Our historical operating losses have resulted principally from our research and development activities, including clinical trial activities for CORLUX, discovery research, non-clinical activities such as toxicology and carcinogenicity studies, manufacturing process development and regulatory activities, as well as general and administrative expenses. We expect to continue to incur net losses over at least the next several years as we continue our CORLUX clinical development program, apply for regulatory approvals, initiate development of newly identified GR-II antagonists for various indications, continue our discovery research program, acquire and develop treatments in other therapeutic areas, establish sales and marketing capabilities and expand our operations.

Our business is subject to significant risks, including the risks inherent in our research and development efforts, the results of our CORLUX clinical trials, uncertainties associated with securing financing, uncertainties associated with obtaining and enforcing patents, our investment in manufacturing set-up, the lengthy and expensive regulatory approval

process and competition from other products. Our ability to successfully generate revenues in the foreseeable future is dependent upon our ability, alone or with others, to finance our operations and develop, obtain regulatory approval for, manufacture and market our lead product.

Results of Operations

Collaboration revenue - Collaboration revenue relates to services rendered in connection with our agreements with Lilly discussed above under the caption "Overview-Management of Weight Gain induced by Antipsychotics." Under these agreements, Lilly has agreed to supply olanzapine and pay for the costs of the studies. We are required to perform development activities as specified in these agreements and we are reimbursed based on the costs associated with the conduct of the studies and the preparation and packaging of clinical trial materials. Revenue is recognized as the services are rendered in accordance with these agreements.

During the nine-months ended September 30, 2007, we recognized revenue of approximately $482,000 from Lilly in regard to our proof-of-concept study evaluating our lead product, CORLUX, for the mitigation of olanzapine induced weight gain in healthy human volunteers. There was no revenue recognized regarding this study during 2008 as the activities for this study were completed during 2007.

During the three months ended September 30, 2008, we recognized revenue from Lilly of approximately $66,000 in connection with the study of the effectiveness of our selective GR-II antagonist, CORT 108297, in rat models of olanzapine induced weight gain.

Research and development expenses. Research and development expenses include the personnel costs related to our development activities, including non-cash stock-based compensation, as well as the costs of discovery research, pre-clinical studies, clinical trial preparations, enrollment and monitoring expenses, regulatory costs, the costs of manufacturing development and the costs of manufacture and / or acquisition of clinical trial materials.

Research and development expenses increased 36% to $3.3 million for the three-month period ended September 30, 2008, from $2.4 million for the three-month period ended September 30, 2007. For the nine-month period ended September 30, 2008, research and development expenses increased 82% to $9.4 million from $5.2 million for the nine-month period ended September 30, 2007. The increase in expenses reflects clinical trial cost increases of approximately $1.1 million and $3.2 million, respectively, for the current quarter and year-to-date periods as compared to the same periods of 2007, related to new trials in psychotic depression and Cushing's Syndrome, which were partially offset by decreases of approximately $1.0 million and $2.3 million, respectively, due to the substantial completion of our earlier Phase 3 clinical trials for psychotic depression, our cardiac study and our proof of concept study in the mitigation of olanzapine induced weight gain in 2007. During the three- and nine-month periods ended September 30, 2008 as compared to the similar periods in 2007, there were also increases in contract research expenses of approximately $155,000 and $1.2 million, respectively, due to basic research work on new chemical compounds and the initiation of the micro-dosing study on a selected compound. In addition, during the nine-month period ended September 30, 2008, there was an increase in manufacturing expenses of approximately $1.1 million, due to the acquisition and manufacture of materials for the new clinical trials and manufacturing process development. During the three- and nine-month periods ended September 30, 2008, as compared to the similar periods in 2007, there were also increases in consulting expenses of approximately $170,000 and $485,000, respectively, and in staffing costs of approximately $220,000 and $465,000, respectively, which included increases in non-cash stock-based compensation of approximately $15,000 and $55,000, respectively.

Below is a summary of our research and development expenses by major project:

                                                        Three Months Ended       Nine Months Ended
                                                          September 30,            September 30,
Project                                                  2008         2007        2008        2007
                                                                      (in thousands)
CORLUX for the treatment of the psychotic features
of psychotic depression                               $    2,162    $  1,918   $    6,011    $ 3,873
CORLUX for other clinical programs                           595         137        1,636        798
Drug discovery research                                      473         307        1,577        368
Stock-based compensation                                      70          64          202        149

Total research and development expense                $    3,300    $  2,426   $    9,426    $ 5,188

We expect that research and development expenditures will increase during the remainder of 2008 as compared to 2007 due to the ongoing Phase 3 studies in psychotic depression and Cushing's Syndrome, the commencement of clinical trials to

further evaluate the management of weight gain induced by antipsychotic medications, and continued development of our proprietary selective GR-II antagonists. Research and development expenses in 2009 and future years will be largely dependent on the availability of additional funds to finance clinical development plans. See also, the "Liquidity and Capital Resources" section in this Form 10-Q.

Many factors can affect the cost and timing of our trials including the pace of patient enrollment, adverse side effects in study patients, adequate supplies for our clinical trials, inconclusive results requiring additional clinical trials and real or perceived lack of effectiveness or safety of the drug in our trials. In addition, the development of all of our product candidates will be subject to extensive governmental regulation. These factors make it difficult for us to predict the timing and costs of the further development and approval of our product candidates.

General and administrative expenses. General and administrative expenses consist primarily of the costs of administrative personnel and related facility costs along with legal, accounting and other professional fees.

General and administrative expenses increased 40% to $1.7 million for the three-month period ended September 30, 2008, from approximately $1.2 million for the three-month period ended September 30, 2007. For the nine-month period ended September 30, 2008, general and administrative expenses increased 38% to $4.3 million from $3.1 million for the nine-month period ended September 30, 2007. The increase in costs between years was primarily related to combined increases in staffing and consultancy costs of approximately $165,000 and $780,000, respectively, for the three- and nine-month periods ended September 30, 2008 as compared to the same periods in 2007, which included increases in non-cash stock-based compensation of approximately $30,000 and $605,000, respectively. The increases in stock-based compensation were due to costs associated with additional stock options and to the inclusion in the second quarter of 2007 of a reversal of approximately $395,000 of stock-compensation expense in connection with the resignation of an employee, which represented the excess of expense under the graded vesting method as compared with the expense associated with stock options that actually vested prior to this termination. In addition, legal and professional services increased by approximately $325,000 and $410,000 for the three- and nine-month periods ended September 30, 2008 as compared to the same periods in 2007 primarily related to patents.

The amount of general and administrative expenses in the remainder of 2008 and future years will be largely dependent on our assessment of the staff necessary to support our continued clinical development activities and the availability of additional funds. See also, the discussion below under the sub-caption - Liquidity and Capital Resources.

Interest and other income, net. Interest and other income, net of investment management fees, was approximately $290,000 and $745,000, respectively, for the three- and nine-month periods ended September 30, 2008, as compared to approximately $190,000 and $455,000, respectively, for the same periods in 2007. Interest income includes approximately $145,000 and $260,000, respectively, for the three- and nine-month periods ended September 30, 2008 that was earned on the note receivable issued in connection with the March 2008 Financing, which amounts had not been received as of September 30, 2008. The remainder of the increase was attributable to increased interest on investments due to higher average balance of invested funds.

Other expense. Other expense was approximately $955,000 and $965,000, respectively for the three- and nine-month periods ended September 30, 2008, as compared to $1,000 and $7,000, respectively, for the same periods in 2007. This increase was primarily related to the incurrence of liquidated damages of approximately $944,000 during the third quarter of 2008 related to the March 2008 Financing. The registration statement covering the securities sold in the March 2008 financing was declared effective by the SEC on November 10, 2008. Accordingly, the Company has recorded additional liquidated damages of approximately $337,000 for the period from October 1 through November 10, 2008.

Liquidity and Capital Resources

We have incurred operating losses since inception, and at September 30, 2008, we had a deficit accumulated during the development stage of $123.9 million. Since our inception, we have relied primarily on the proceeds from public and private sales of our equity securities to fund our operations.

On March 25, 2008, we sold approximately 8.9 million shares of our common stock at a price of $2.77 per share and warrants to purchase approximately 4.5 million shares of our common stock, at a price of $0.125 per warrant in a private placement, reflecting a total unit price of $2.84. The warrants have a seven year term and an exercise price of $2.77 per share. We refer to this transaction as the March 2008 Financing. One investor financed the purchase of its securities in this transaction with a promissory note to the Company in the amount of $6.0 million. The note receivable, as amended, is payable on or before December 12, 2008, currently bears interest to the Company at a rate of 9.25% per annum as of September 30, 2008, is a full recourse note and is secured by a pledge of the securities purchased together with additional securities owned by the borrower. The March 2008 Financing will have generated total proceeds of approximately $25 million, after deducting the costs of issuance, assuming

payment is received on the note. If the amended note receivable is not repaid pursuant to its terms, we intend to seize and potentially liquidate the collateral and take whatever further legal actions may be necessary to compel the investor to satisfy the obligations under the amended note. Our operating plan assumes that we will receive the cash amount due to us under the amended note, including interest. If we are not able to recover the full amount due to us under the amended note, either from the investor or as a result of liquidating the collateral, we may not be able to fund our operating plan as currently contemplated and may need to delay, reduce the scope of or eliminate a portion of our research or development programs.

The registration rights agreement covering the securities sold in this financing provides that if we fail to file or cause to be declared effective the registration statement or registration statements covering the resale of these shares prior to specified deadlines, we may be required to pay the holders of such shares and warrants liquidated damages at the rate of 1% per month of the purchase price of these shares and warrants, up to a total of 10%. While we filed the registration statement covering the resale of the shares sold and shares underlying the warrants sold in this transaction with the SEC on April 11, 2008, within the time period required in the agreement, this registration statement was not declared effective by the SEC until November 10, 2008. Accordingly, we accrued a liability of approximately $944,000 related to the liquidated damages to investors in this financing for the period from July 8 through September 30, 2008, and have accrued an additional amount of approximately $337,000 for liquidated damages covering the period from October 1 to November 10, 2008, the date the registration statement was declared effective. On November 11, 2008, the Company's board of directors approved the issuance of shares of the Company's common stock in lieu of paying the . . .