Nature of Business	3 Months Ended
Mar. 31, 2021
Nature of Business
Nature of Business	Rhythm Pharmaceuticals, Inc. Notes to Unaudited Condensed Consolidated Financial Statements (In thousands, except share and per share information) 1. Nature of Business Rhythm Pharmaceuticals, Inc. (the “Company” or “we”) is a commercial-stage biopharmaceutical company focused on changing the paradigm for the treatment of rare genetic diseases of obesity, which are characterized by early-onset, severe obesity and an insatiable hunger or hyperphagia. Our lead product candidate is IMCIVREE (setmelanotide), a potent melanocortin-4 receptor, or MC4R, agonist for the treatment of rare genetic diseases of obesity. We believe IMCIVREE, for which we have exclusive worldwide rights, has the potential to restore dysfunctional MC4R signaling due to impaired MC4R pathway function. MC4R pathway deficiencies result in the disruption of satiety signals and energy homeostasis in the body, which, in turn, leads to intense feelings of hunger and to obesity. IMCIVREE has been approved by the U.S. Food and Drug Administration, or FDA, for chronic weight management in adult and pediatric patients six years of age and older with obesity due to proopiomelanocortin, or POMC, proprotein convertase subtilisin/kexin type 1, or PCSK1, or leptin receptor, or LEPR, deficiency confirmed by genetic testing. IMCIVREE is now commercially available. The Company is a Delaware corporation organized in February 2013 under the name Rhythm Metabolic, Inc., and as of October 2015, under the name Rhythm Pharmaceuticals, Inc. The Company’s continued development efforts are focused on obesity related to several single gene-related, or monogenic, MC4R pathway deficiencies: Bardet-Biedl syndrome, or BBS; Alström syndrome; HET obesity due to a genetic variant in one of the two alleles of the POMC, PCSK1 or LEPR gene, or HETs; obesity due to steroid receptor coactivator 1, or SRC1, deficiency; and obesity due to SH2B adapter protein 1, or SH2B1, deficiency; MC4R deficiency obesity and Smith-Magenis syndrome, as well as additional diseases as part of investigator-initiated protocols. Currently, there are no effective or approved treatments for these MC4R pathway-related diseases. The Company believes that the MC4R pathway is a compelling target for treating these genetic diseases because of its critical role in regulating appetite and weight by promoting satiety and weight control, and that peptide therapeutics are uniquely suited for activating this target. The Company is subject to risks and uncertainties common to commercial-stage companies in the biotechnology industry, including but not limited to risks associated with the commercialization of approved products, completing preclinical studies and clinical trials, receiving regulatory approvals for product candidates, development by competitors of new biopharmaceutical products, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Commercialization of approved products will require significant resources and in order to market IMCIVREE, the Company must continue to build its sales, marketing, managerial and other non-technical capabilities or make arrangements with third parties to perform these services. Product candidates currently under development will require significant additional research and development efforts, including preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Liquidity The Company has incurred operating losses and negative cash flows from operations since inception. As of March 31, 2021, the Company had an accumulated deficit of $415,577. The Company has primarily funded these losses through the proceeds from the sales of common and preferred stock, asset sales as well as capital contributions received from the former parent company, Rhythm Holdings LLC. To date, the Company has minimal product revenue and management expects operating losses to continue for the foreseeable future. The Company has devoted substantially all of its resources to its drug development efforts, comprising of research and development, manufacturing, conducting clinical trials for its product candidates, protecting its intellectual property, pre-commercialization activities and general and administrative functions relating to these operations. The future success of the Company is dependent on its ability to develop its product candidates and ultimately upon its ability to attain profitable operations. In February 2021, the Company completed the sale of a Rare Pediatric Disease Priority Review Voucher, or PRV, that it received in connection with the approval of IMCIVREE for $100,000. As the PRV did not have a carrying value, the gain recognized within Other income (loss) was equal to the gross proceeds received, with costs related to the sale of the voucher recorded within selling, general and administrative expenses. At March 31, 2021, the Company had $404,750 of cash and cash equivalents and short-term investments on hand. In the future, the Company will be dependent on obtaining funding from third parties, such as proceeds from the issuance of debt, sale of equity, product sales and funded research and development programs to maintain the Company's operations and meet the Company's obligations. There is no guarantee that additional equity or other financings will be available to the Company on acceptable terms, or at all. If the Company fails to obtain additional funding when needed, the Company would be forced to scale back, terminate its operations or seek to merge with or be acquired by another company. Management believes that the Company's existing cash resources will be sufficient to fund the Company's operations into at least the second half of 2023.

Nature of Business

3 Months Ended

Mar. 31, 2021

Rhythm Pharmaceuticals, Inc.

Notes to Unaudited Condensed Consolidated Financial Statements

(In thousands, except share and per share information)

1. Nature of Business

Rhythm Pharmaceuticals, Inc. (the “Company” or “we”) is a commercial-stage biopharmaceutical company focused on changing the paradigm for the treatment of rare genetic diseases of obesity, which are characterized by early-onset, severe obesity and an insatiable hunger or hyperphagia. Our lead product candidate is IMCIVREE (setmelanotide), a potent melanocortin-4 receptor, or MC4R, agonist for the treatment of rare genetic diseases of obesity. We believe IMCIVREE, for which we have exclusive worldwide rights, has the potential to restore dysfunctional MC4R signaling due to impaired MC4R pathway function. MC4R pathway deficiencies result in the disruption of satiety signals and energy homeostasis in the body, which, in turn, leads to intense feelings of hunger and to obesity. IMCIVREE has been approved by the U.S. Food and Drug Administration, or FDA, for chronic weight management in adult and pediatric patients six years of age and older with obesity due to proopiomelanocortin, or POMC, proprotein convertase subtilisin/kexin type 1, or PCSK1, or leptin receptor, or LEPR, deficiency confirmed by genetic testing. IMCIVREE is now commercially available.

The Company is a Delaware corporation organized in February 2013 under the name Rhythm Metabolic, Inc., and as of October 2015, under the name Rhythm Pharmaceuticals, Inc.

The Company’s continued development efforts are focused on obesity related to several single gene-related, or monogenic, MC4R pathway deficiencies: Bardet-Biedl syndrome, or BBS; Alström syndrome; HET obesity due to a genetic variant in one of the two alleles of the POMC, PCSK1 or LEPR gene, or HETs; obesity due to steroid receptor coactivator 1, or SRC1, deficiency; and obesity due to SH2B adapter protein 1, or SH2B1, deficiency; MC4R deficiency obesity and Smith-Magenis syndrome, as well as additional diseases as part of investigator-initiated protocols. Currently, there are no effective or approved treatments for these MC4R pathway-related diseases. The Company believes that the MC4R pathway is a compelling target for treating these genetic diseases because of its critical role in regulating appetite and weight by promoting satiety and weight control, and that peptide therapeutics are uniquely suited for activating this target.

The Company is subject to risks and uncertainties common to commercial-stage companies in the biotechnology industry, including but not limited to risks associated with the commercialization of approved products, completing preclinical studies and clinical trials, receiving regulatory approvals for product candidates, development by competitors of new biopharmaceutical products, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Commercialization of approved products will require significant resources and in order to market IMCIVREE, the Company must continue to build its sales, marketing, managerial and other non-technical capabilities or make arrangements with third parties to perform these services. Product candidates currently under development will require significant additional research and development efforts, including preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities.

Liquidity

The Company has incurred operating losses and negative cash flows from operations since inception. As of March 31, 2021, the Company had an accumulated deficit of $415,577. The Company has primarily funded these losses through the proceeds from the sales of common and preferred stock, asset sales as well as capital contributions received from the former parent company, Rhythm Holdings LLC. To date, the Company has minimal product revenue and management expects operating losses to continue for the foreseeable future. The Company has devoted substantially all of its resources to its drug development efforts, comprising of research and development, manufacturing, conducting clinical trials for its product candidates, protecting its intellectual property, pre-commercialization activities and general and

administrative functions relating to these operations. The future success of the Company is dependent on its ability to develop its product candidates and ultimately upon its ability to attain profitable operations.

In February 2021, the Company completed the sale of a Rare Pediatric Disease Priority Review Voucher, or PRV, that it received in connection with the approval of IMCIVREE for $100,000. As the PRV did not have a carrying value, the gain recognized within Other income (loss) was equal to the gross proceeds received, with costs related to the sale of the voucher recorded within selling, general and administrative expenses.

At March 31, 2021, the Company had $404,750 of cash and cash equivalents and short-term investments on hand. In the future, the Company will be dependent on obtaining funding from third parties, such as proceeds from the issuance of debt, sale of equity, product sales and funded research and development programs to maintain the Company's operations and meet the Company's obligations. There is no guarantee that additional equity or other financings will be available to the Company on acceptable terms, or at all. If the Company fails to obtain additional funding when needed, the Company would be forced to scale back, terminate its operations or seek to merge with or be acquired by another company. Management believes that the Company's existing cash resources will be sufficient to fund the Company's operations into at least the second half of 2023.