Biggest changeIn the comparable periods in 2021 and 2020, we spent $318.8 million and $11.0 million, respectively, acquiring shares of our common stock, offset by $16.2 million and $23.2 million received from the exercise of stock options, respectively, resulting in net cash used in financing activities of $302.6 million for the year ended and net cash provided by financing activities of $12.2 million for the year ended December 31, 2020.
Biggest changeIn the year ended December 31, 2023, we spent $154.5 million acquiring shares of our common stock, comprised of $145.4 million pursuant to our tender offer, $7.4 million acquiring shares of our common stock in connection with the net exercise of employee and director stock options and $1.7 million to satisfy tax withholding requirements from vesting of restricted stock grants, offset by $3.8 million received in connection with our ESPP and $2.0 million net cash received from the exercise of stock options, resulting in net cash used in financing activities of $148.7 million.
The cash in our bank accounts and our marketable securities could be reduced or our access to them restricted if the financial institutions holding them were to fail or severely adverse conditions were to arise in the markets for public or private debt securities. We have never experienced a lack of access to cash or material realized losses.
The cash in our bank accounts and our marketable securities could be reduced or our access to them restricted if the financial institutions holding them were to fail or severely adverse conditions were to arise in the markets for public or private debt securities. We have never experienced a material lack of access to cash or material realized losses.
Benefits of orphan drug designation by the EC are similar, but also 31 include protocol assistance from the European Medicines Agency (“EMA”), access to the centralized marketing authorization procedure in the European Union (“EU”) and, if we obtain approval, ten years of exclusive marketing rights in the EU for the treatment of patients with Cushing’s syndrome.
Benefits of orphan drug designation by the EC are similar, but also include protocol assistance from the European Medicines Agency (“EMA”), access to the centralized marketing authorization procedure in the European Union (“EU”) and, if we obtain approval, ten years of exclusive marketing rights in the EU for the treatment of patients with Cushing’s syndrome.
Relacorilant is also expected to treat the patients’ Cushing’s syndrome generated by their tumors’ excess production of cortisol. Relacorilant in Patients with Prostate Cancer . Androgen deprivation is the standard treatment for prostate cancer because androgens stimulate prostate tumor growth. Tumors often escape androgen deprivation therapy when cortisol’s activity at the GR stimulates tumor growth.
Relacorilant is also expected to treat the patients’ Cushing’s syndrome generated by their tumors’ excess production of cortisol. 31 Relacorilant in Patients with Prostate Cancer . Androgen deprivation is the standard treatment for prostate cancer because androgens stimulate prostate tumor growth. Tumors often escape androgen deprivation therapy when cortisol’s activity at the GR stimulates tumor growth.
We are providing relacorilant and placebo for the study and have licensed patents covering the use of relacorilant combined with anticancer agents such as enzalutamide in the treatment of patients with this indication. 32 Amyotrophic Lateral Sclerosis (“ALS” ) ALS, also known as Lou Gehrig’s disease, is a devastating neuromuscular illness.
We are providing relacorilant and placebo for the study and have licensed patents covering the use of relacorilant combined with anticancer agents such as enzalutamide in the treatment of patients with this indication. Amyotrophic Lateral Sclerosis (“ALS” ) ALS, also known as Lou Gehrig’s disease, is a devastating neuromuscular illness.
We provide financial assistance to eligible patients whose insurance policies have high deductibles or co-payments and deduct the amount of such assistance from gross revenue. We determine the assistance we provide each patient by applying our program guidelines to that patient’s financial 36 position and their insurance policy’s co-payment and deductible requirements.
We provide financial assistance to eligible patients whose insurance policies have high deductibles or co-payments and deduct the amount of such assistance from gross revenue. We determine the assistance we provide each patient by applying our program guidelines to that patient’s financial position and their insurance policy’s co-payment and deductible requirements.
To help us achieve that goal, we fund our own patient support programs and donate money to independent charitable foundations that help patients pay for all aspects of their Cushing’s syndrome care, whether or not that care includes taking Korlym. Relacorilant .
To help us achieve that goal, we fund our own patient support programs and donate money to independent charitable foundations that help patients pay for all aspects of their Cushing’s syndrome care, whether or not that care includes taking Korlym.
Our selective cortisol modulator dazucorilant improved motor performance and reduced neuroinflammation and muscular atrophy in animal models of ALS. Following these compelling results, in October 2022 we initiated a Phase 2 trial of dazucorilant (the “DAZALS” trial) in patients with ALS.
Our selective cortisol modulator dazucorilant improved motor performance and reduced neuroinflammation and muscular atrophy in animal models of ALS. Following these compelling results, we initiated a Phase 2 trial (“DAZALS”) of dazucorilant in patients with ALS in October 2022.
Cost of sales – Cost of sales includes the cost of API, tableting, packaging, personnel, overhead, stability testing and distribution. Cost of sales was $5.4 million for the year ended December 31, 2022, compared to $5.3 million and $5.6 million for the years ended December 31, 2021 and 2020, respectively.
Cost of sales – Cost of sales includes the cost of API, tableting, packaging, personnel, overhead, stability testing and distribution. Cost of sales was $6.5 million for the year ended December 31, 2023, compared to $5.4 million and $5.3 million for the years ended December 31, 2022 and 2021, respectively.
The primary endpoint is PFS, with overall survival as a key secondary endpoint. Patients in ROSELLA will have received prior bevacizumab therapy, which is the standard of care in the United States for patients with platinum-resistant ovarian cancer.
The primary endpoint is PFS; overall survival is a key secondary endpoint. Patients in ROSELLA will have received prior bevacizumab therapy, which is the standard of care for patients with platinum-resistant ovarian cancer.
Relacorilant shares Korlym’s affinity for the glucocorticoid receptor (“GR”), but, unlike Korlym, has no affinity for the progesterone receptor (“PR”), and so is not the “abortion pill” and does not cause other effects associated with PR affinity, including endometrial thickening and vaginal bleeding.
Relacorilant shares Korlym’s affinity for the glucocorticoid receptor (“GR”), but, unlike Korlym, has no affinity for the progesterone receptor (“PR”), and so is not the “abortion pill.” It does not cause other effects associated with PR affinity, including endometrial thickening and vaginal bleeding.
If successful, we expect GRACE to provide the basis for a new drug application (“NDA”) for relacorilant as a treatment for patients with any etiology of endogenous Cushing’s syndrome. Our second Phase 3 trial of relacorilant, GRADIENT, is studying patients whose Cushing’s syndrome is caused by a benign adrenal tumor.
If successful, GRACE will provide the basis for a new drug application (“NDA”) for relacorilant as a treatment for patients with any etiology of endogenous Cushing’s syndrome. 30 Our second Phase 3 trial of relacorilant, GRADIENT, is studying patients whose Cushing’s syndrome is caused by a benign adrenal tumor.
Combining a cortisol modulator with an androgen modulator may block this escape route. Our collaborators at the University of Chicago plan to initiate a randomized, placebo-controlled Phase 2 trial of relacorilant plus enzalutamide in patients with prostate cancer, pre-prostatectomy.
Combining a cortisol modulator with an androgen modulator may block this escape route. Our collaborators at the University of Chicago have initiated a randomized, placebo-controlled Phase 2 trial of relacorilant plus enzalutamide in patients with prostate cancer, pre-prostatectomy.
NASH is an advanced form of nonalcoholic fatty liver disease that afflicts millions of patients and is a leading cause of liver-related mortality.
Nonalcoholic steatohepatitis (“NASH”) is an advanced form of nonalcoholic fatty liver disease that afflicts millions of patients and is a leading cause of liver-related mortality.
We are conducting two Phase 3 trials (named GRACE and GRADIENT) of our proprietary, selective cortisol modulator, relacorilant, as a treatment for patients with Cushing’s syndrome. Relacorilant was well-tolerated in its Phase 1 and Phase 2 trials.
We are conducting two Phase 3 trials (“GRACE” and “GRADIENT”) of our proprietary, selective cortisol modulator, relacorilant, as a treatment for patients with Cushing’s syndrome. Relacorilant was well-tolerated in its Phase 1 and Phase 2 trials.
Women with a history of tumors that do not respond to initial platinum-based treatments (i.e., women with “primary platinum-refractory” disease) and those who have received more than three prior lines of therapy will be excluded.
Women with a history of tumors that do not respond to initial platinum-based treatments (i.e., women with “primary platinum-refractory” disease) and those who have received more than three prior lines of therapy will be excluded. Relacorilant in Patients with Adrenal Cancer with Cortisol Excess .
Because many people who suffer from Cushing’s syndrome are undiagnosed or inadequately treated, we have developed and continue to refine and expand programs to educate physicians and patients about screening for hypercortisolism and the role Korlym can play in treating patients with the disorder. We also have a field-based force of medical science liaisons.
Because many people who suffer from Cushing’s syndrome are undiagnosed or inadequately treated, we have developed and continue to refine and expand programs to educate physicians and patients about screening for hypercortisolism and the role Korlym can play in treating patients with the disorder.
Patients who exhibit pre-specified improvements in hypertension and/or glucose metabolism enter a 12-week, double-blind, “randomized withdrawal” phase, in which half of the patients continue receiving relacorilant and half receive placebo.
In the GRACE trial, each patient receives relacorilant for 22 weeks. Patients who exhibit pre-specified improvements in hypertension and/or glucose metabolism enter a 12-week, double-blind, “randomized withdrawal” phase, in which half of the patients continue receiving relacorilant and half receive placebo.
Research and development expense – Research and development expense includes the cost of (1) recruiting and compensating development personnel, (2) clinical trials, (3) drug product and preclinical studies in support of clinical trials and regulatory submissions, (4) discovery research and (5) the development of drug formulations and manufacturing processes.
Research and development expense – Research and development expense includes the cost of (1) clinical trials, (2) recruiting and compensating development personnel, (3) manufacturing investigational drug product (4) preclinical studies, (5) drug discovery research and (6) the development of new drug formulations and manufacturing processes.
In April 2021, we suspended our Phase 2a trial of our selective cortisol modulator miricorilant as a potential treatment for NASH after four of the five patients who received miricorilant exhibited both elevated liver enzymes and large rapid reductions in liver fat. Liver enzyme levels in all affected patients returned to baseline or below baseline after miricorilant was withdrawn.
In April 2021, we suspended our Phase 2a trial of our selective cortisol modulator miricorilant as a potential treatment for NASH after four of the five patients who received miricorilant exhibited both elevated liver enzymes and large rapid reductions in liver fat.
Cost of sales includes the cost of manufacturing Korlym, including materials, third-party manufacturing costs and indirect personnel and other overhead costs, based on the number of Korlym tablets for which we recognize revenue, as well as costs of stability testing, logistics and distribution.
We destroy expired inventory and recognize the related costs as cost of sales in that period’s statement of income. 35 Cost of sales includes the cost of manufacturing Korlym, including materials, third-party manufacturing costs and indirect personnel and other overhead costs, based on the number of Korlym tablets for which we recognize revenue, as well as costs of stability testing, logistics and distribution.
Research and development expense was $131.0 million for the year ended December 31, 2022, compared to $113.9 million for the comparable period in 2021. The increase was primarily due to the advancement of our development programs and increased spending on employee compensation expenses.
Research and development expense was $184.4 million for the year ended December 31, 2023, compared to $131.0 million and $113.9 million for the years ended December 31, 2022 and 2021, respectively. The increase for the year ended December 31, 2023 compared to 2022 was primarily due to increased spending on our development programs and employee compensation expenses.
The trial’s primary endpoint is the rate and degree of relapse of hypertension in patients receiving placebo measured against the rate and degree of relapse of hypertension in those continuing relacorilant. GRACE has a planned enrollment of 130 patients with Cushing’s syndrome at sites in the United States, Canada, Europe and Israel.
The trial’s primary endpoint is the rate and degree of relapse of hypertension in patients receiving placebo measured against the rate and degree of relapse of hypertension in those continuing relacorilant. GRACE has enrolled 152 patients at sites in the United States, Canada, Europe and Israel. Enrollment is now complete.
To determine the appropriate amount to reserve against these rebates, we identify Korlym sold to patients covered by government-funded programs, apply the applicable government discount to these sales, then estimate the portion of total rebates we expect will be claimed.
To determine the appropriate amount to reserve against these rebates, we identify Korlym sold to patients covered by government-funded programs, apply the applicable government discount to these sales, then estimate utilization of such programs by government payors.
Selling, general and administrative expense was $152.8 million for the year ended December 31, 2022, compared to $122.4 million for the comparable period in 2021. The increase was primarily due to increased sales and marketing activities, employee compensation expenses, and legal fees.
Selling, general and administrative expense for the years ended December 31, 2023, 2022 and 2021 was $184.3 million, $152.8 million and $122.4 million, respectively. The increase for the year ended December 31, 2023 compared to 2022 was primarily due to increased employee compensation expenses and legal fees.
In the year ended December 31, 2022, we spent $21.7 million acquiring shares of our common stock in connection with the net exercise of employee and director stock options and vesting of restricted stock grants, offset by $4.4 million received from the exercise of stock options and purchases through our Employee Stock Purchase Plan, resulting in net cash used in financing activities of $17.3 million.
For the year ended December 31, 2022, we spent $21.7 million acquiring shares of our common stock, offset by $4.4 million received from the exercise of stock options, resulting in net cash used in financing activities of $17.3 million.
In the United States, relacorilant’s orphan designation confers tax credits, reduced regulatory fees and, provided we obtain approval for the treatment of patients with Cushing’s syndrome, seven years of exclusive marketing rights.
The United States Food and Drug Administration (“FDA”) and the European Commission (“EC”) have designated relacorilant as an orphan drug for the treatment of Cushing’s syndrome. In the United States, relacorilant’s orphan designation confers tax credits, reduced regulatory fees and, provided we obtain approval for the treatment of patients with Cushing’s syndrome, seven years of exclusive marketing rights.
However, multiple replicated pre-clinical results as well as the results of our double-blind, placebo-controlled trial (published in the Journal of Clinical Psychopharmacology (Hunt et al., 2021)) suggest that miricorilant has the potential to significantly reduce weight gain caused by the administration of olanzapine. Accordingly, we plan to further study miricorilant’s potential to prevent AIWG.
However, numerous replicated pre-clinical study results as well as the results of our double-blind, placebo-controlled trial in healthy subjects (published in the Journal of Clinical Psychopharmacology (Hunt et al., 2021)) suggest that miricorilant may significantly prevent weight gain caused by the administration of olanzapine.
As of December 31, 2022, we had cash, cash equivalents and marketable securities of $436.6 million, consisting of cash and cash equivalents of $66.3 million and marketable securities of $370.3 million, compared to cash, cash equivalents and marketable securities of $335.8 million, consisting of cash and cash equivalents of $77.6 million and marketable securities of $258.2 million as of December 31, 2021.
As of December 31, 2023, we had cash, cash equivalents and marketable securities of $425.4 million, consisting of cash and cash equivalents of $135.6 million and marketable securities of $289.8 million, compared to cash, cash equivalents and marketable securities of $436.6 million, consisting of cash and cash equivalents of $66.3 million and marketable securities of $370.3 million as of December 31, 2022.
Income tax expense – Income tax expense was $14.8 million for the year ended December 31, 2022, compared to $12.5 million for the comparable period in 2021. Income tax expense increased for the year ended December 31, 2022 from the comparable period in 2021 due to decreased excess tax benefits for stock option exercises compared to 2021.
Income tax expense – Income tax expense for the years ended December 31, 2023, 2022, and 2021 was $18.4 million, $14.8 million, and $12.5 million, respectively. The increase for the year ended December 31, 2023 compared to 2022 was due to decreased excess tax benefits for stock option exercises.
Safety and tolerability of relacorilant plus nab-paclitaxel were comparable to nab-paclitaxel monotherapy. In June 2022, we initiated a pivotal Phase 3 trial (“ROSELLA”) that seeks to replicate the positive results observed in our Phase 2 study. ROSELLA has a planned enrollment of 360 women with recurrent, platinum-resistant ovarian cancer, randomized 1:1 to receive either relacorilant plus nab-paclitaxel or nab-paclitaxel monotherapy.
In June 2022, we initiated a pivotal Phase 3 trial (“ROSELLA”) that seeks to replicate the positive results observed in our Phase 2 study. ROSELLA has a planned enrollment of 360 women with recurrent, platinum-resistant ovarian cancer, half of whom will receive 150 mg of relacorilant intermittently in addition to nab-paclitaxel, with the other half receiving nab-paclitaxel monotherapy.
We base our estimates on historical experience and on other assumptions we believe to be reasonable. Actual results may differ from our estimates. Our significant accounting policies are described in Note 1, Basis of Presentation and Summary of Significant Accounting Policies , of the Notes to Consolidated Financial Statements included in Part IV of this Annual Report on Form 10-K.
Our significant accounting policies are described in Note 1, Basis of Presentation and Summary of Significant Accounting Policies , of the Notes to Consolidated Financial Statements included in Part IV of this Annual Report on Form 10-K.
Interest and other income – Interest and other income for the years ended December 31, 2022, 2021 and 2020 was $3.6 million, $0.5 million and $3.4 million, respectively, and consisted primarily of interest income from marketable securities.
Interest and other income – Interest and other income for the years ended December 31, 2023, 2022 and 2021 was $17.3 million, $3.6 million and $0.5 million, respectively, and consisted primarily of interest income from marketable securities. The increase for the year ended December 31, 2023 compared to 2022 was due to market-wide increase in interest rates.
The increase was primarily due to increases in employee recruiting and compensation expenses, sales and marketing expenses and professional services. 34 We expect our selling, general and administrative expense to be higher in 2023 than in 2022 due to increased commercial and administrative activities, including litigation and administrative support for increased research and development and marketing efforts.
We expect our selling, general and administrative expense to be higher in 2024 than in 2023 due to increased commercial and administrative activities, including litigation and administrative support for increased research and development and marketing efforts.
Selling, general and administrative expense – Selling, general and administrative expense includes (1) compensation of employees, consultants and contractors engaged in commercial and administrative activities, (2) the cost of vendors supporting commercial activities and (3) legal and accounting fees.
Research and development spending in future years will depend on the outcome of our pre-clinical and clinical trials and our development plans. 33 Selling, general and administrative expense – Selling, general and administrative expense includes (1) compensation of employees, consultants and contractors engaged in commercial and administrative activities, (2) the cost of vendors supporting commercial activities and (3) legal and accounting fees.
The increase for the year ended December 31, 2021 compared to 2020 was primarily due to higher revenue. Net cash (used in) provided by investing activities for the year ended December 31, 2022, 2021 and 2020 was $(114.3) million, $136.1 million and $(119.3) million, respectively.
Net cash provided by (used in) investing activities for the years ended December 31, 2023, 2022 and 2021 was $90.9 million, $(114.3) million and $136.1 million, respectively.
Net cash provided by operating activities for the years ended December 31, 2022, 2021 and 2020 was $120.3 million, $167.9 million and $152.0 million, respectively. The decrease for the year ended December 31, 2022 compared to 2021 was primarily due to higher current income taxes resulting from the capitalization of research and development costs for tax purposes.
Net cash provided by operating activities for the years ended December 31, 2023, 2022 and 2021 was $127.0 million, $120.3 million and $167.9 million, respectively. The increase for the year ended December 31, 2023 compared to 2022 was primarily due to higher revenue.
In addition, clinical development is subject to government oversight and regulations that may change without notice. We expect our research and development expense to be higher in 2023 than in 2022 as our clinical programs advance. Research and development spending in future years will depend on the outcome of our pre-clinical and clinical trials and our development plans.
In addition, clinical development is subject to government oversight and regulations that may change without notice. We expect our research and development expense to be higher in 2024 than in 2023 as we add new clinical trials and our existing trials enroll more patients.
Overview We are a commercial-stage company engaged in the discovery and development of medications to treat severe endocrine, oncologic, metabolic and neurological disorders by modulating the effects of the hormone cortisol. Cushing’s Syndrome Korlym . We sell Korlym in the United States, using experienced sales representatives to call on physicians caring for patients with endogenous Cushing’s syndrome (hypercortisolism).
Overview We are a commercial-stage company engaged in the discovery and development of medications to treat severe endocrinologic, oncologic, metabolic and neurologic disorders by modulating the effects of the hormone cortisol. Since 2012, we have marketed Korlym ® for the treatment of patients suffering from Cushing’s syndrome.
Net Operating Loss Carryforwards See Note 9 , Income Taxes in our audited consolidated financial statements. Critical Accounting Policies and Estimates Our consolidated financial statements have been prepared in accordance with U.S. GAAP, which requires us to make estimates and judgments that affect the amount of assets, liabilities and expenses we report.
As of December 31, 2023, we had retained earnings of $402.5 million. 34 Net Operating Loss Carryforwards See Note 9 , Income Taxes in our audited consolidated financial statements. Critical Accounting Policies and Estimates Our consolidated financial statements have been prepared in accordance with U.S.
Some of our trials of indications not considered immediately life-threatening, such as Cushing’s syndrome, have experienced slower enrollment. In addition, some clinical sites have reduced the frequency with which physicians see study participants. Our trials in patients with immediately life-threatening diseases, such as our Phase 2 trial in women with platinum-resistant ovarian cancer, have not encountered delays.
The pandemic’s impact on our clinical development programs was variable. Some of our trials of indications not considered immediately life-threatening, such as Cushing’s syndrome, experienced slower enrollment and difficulty retaining patients. In addition, some clinical sites reduced the frequency with which physicians were able to examine study participants.
Cost of sales as a percentage of revenue was 1.3 percent, 1.4 percent and 1.6 percent for the years ended December 31, 2022, 2021 and 2020, respectively. The decreases in cost of sales as a percentage of revenue are due to reduced manufacturing costs and increased price of Korlym.
Cost of sales as a percentage of revenue was 1.3 percent for each of the years ended December 31, 2023 and 2022.
Relacorilant also does not appear to cause hypokalemia (low potassium), a potentially serious condition that is a leading cause of patients stopping treatment with Korlym. Forty-four percent of patients in Korlym’s pivotal trial experienced hypokalemia. In the GRACE trial, each patient receives relacorilant for 22 weeks.
There is no evidence that relacorilant causes hypokalemia (low potassium), a potentially serious condition that is a leading cause of patients stopping treatment with Korlym. Forty-four percent of patients in Korlym’s pivotal trial experienced hypokalemia. Unlike all other medications used to treat Cushing’s syndrome, relacorilant does not prolong the heart’s QT interval, a potentially deadly off-target effect.
The change for the year ended December 31, 2022 compared to 2021 was primarily due to allocation of cash generated from our operating activities towards marketable securities rather than share repurchases.
The change for the year ended December 31, 2023 compared to 2022 was primarily due to allocation of cash proceeds from maturities of marketable securities towards cash equivalents in anticipation of the closing of our tender offer in April 2023 and in anticipation of our share buyback program announced in January 2024.
Year Ended December 31, 2022 2021 2020 (1) (in thousands) Development programs: Oncology $ 20,987 $ 17,984 $ 34,207 Cushing’s syndrome 30,031 28,639 26,821 Metabolic diseases 24,270 20,594 20,408 Pre-clinical and early-stage selective cortisol modulators and ALS 26,084 21,924 14,726 Unallocated activities, including manufacturing and regulatory activities 16,819 10,617 7,380 Stock-based compensation 12,800 14,106 11,222 Total research and development expense $ 130,991 $ 113,864 $ 114,764 (1) Beginning in the first quarter of 2021, expenses for the year ended December 31, 2020 previously allocated to oncology and endocrinology were re-allocated between Cushing's syndrome, metabolic diseases and pre-clinical development programs.
Year Ended December 31, 2023 2022 2021 (in thousands) Development programs: Oncology $ 41,433 $ 20,987 $ 17,984 Cushing’s syndrome 41,196 30,031 28,639 Metabolic diseases 36,104 24,270 20,594 Pre-clinical and early-stage selective cortisol modulators and ALS 30,852 26,084 21,924 Unallocated activities, including manufacturing and regulatory activities 19,366 16,819 10,617 Stock-based compensation 15,402 12,800 14,106 Total research and development expense $ 184,353 $ 130,991 $ 113,864 It is difficult to predict the timing and cost of development activities, which are subject to many uncertainties and risks, including inconclusive or negative results, slow patient enrollment, adverse side effects and difficulties in the formulation or manufacture of study drugs and lack of drug-candidate efficacy.
COVID-19 Pandemic Public health restrictions put in place to reduce the impact of the global COVID-19 pandemic, as well as measures voluntarily undertaken by patients, physicians, hospitals and medical clinics, have reduced our revenue growth and make it difficult to grow our Korlym business. The pandemic’s impact on the pace of our clinical development programs has been variable.
In October 2023, we initiated a double-blind, placebo-controlled, Phase 1 trial to further study miricorilant’s potential to prevent AIWG. COVID-19 Pandemic Public health restrictions and measures voluntarily undertaken by patients, physicians, hospitals and health clinics to reduce the impact of COVID-19 reduced our revenue growth and made it difficult to grow our Korlym business.
For the years ended December 31, 2022 and 2021, sales 33 volume accounted for 54.6 percent and 20.7 percent of the increases, respectively. Increases in the average price of Korlym accounted for the remaining growth due to price increases effective January 1, 2022 and March 1, 2021.
Net product revenue was $482.4 million for the year ended December 31, 2023, compared to $401.9 million and $366.0 million for the years ended December 31, 2022 and 2021, respectively. Higher sales volume accounted for 57.4 percent of the increase for the year ended December 31, 2023, with the remaining growth due to a price increase effective January 1, 2023.
In the United States, six million people take antipsychotic medications such as olanzapine and risperidone to treat illnesses such as schizophrenia, bipolar disorder and depression. While these drugs are very effective, they often cause rapid and sustained weight gain, other metabolic disturbances and, ultimately, cardiovascular disease.
While these drugs are very effective, they often cause rapid and sustained weight gain, other metabolic disturbances and, ultimately, cardiovascular disease. Patients taking these medications experience a 10 to 25-year reduction in life expectancy, due largely to increased cardiovascular events, such as heart attacks and strokes.
While our core effective tax rate has remained relatively consistent throughout the years, the tax rate can vary based upon the timing of provisions related to discrete tax items, including current and future excess tax benefits from stock-based compensation. Liquidity and Capital Resources Since 2015, we have relied on revenues from the sale of Korlym to fund our operations.
Liquidity and Capital Resources Since 2015, we have relied on revenues from the sale of Korlym to fund our operations.
The IRA includes provisions imposing a 1% excise tax on share repurchases that occur after December 31, 2022 and introduces a 15% corporate alternative minimum tax (“CAMT”) on adjusted financial statement income. The CAMT will be effective for us beginning on January 1, 2024. We do not expect the CAMT to have a significant effect on our consolidated financial statements.
The IRA also permits CMS to negotiate prices for certain high-expenditure Medicare Part B or Part D drugs, imposes a one percent excise tax on certain share repurchases and introduces a 15 percent corporate alternative minimum tax on adjusted financial statement income. The corporate alternative minimum tax became effective for us on January 1, 2024.