issued and sold pursuant to the Sales Agreement prior to February 29, 2024). In connection with the Amendment, on February 29, 2024, the Company filed with the SEC a prospectus supplement, dated February 29, 2024, which, combined with the Base Prospectus (together, the “New Prospectus”), amended the Prior Prospectus in its entirety. The issuances and sales under the Sales Agreement, as amended by the Amendment, will be made pursuant to the Registration Statement and the New Prospectus.
On February 9, 2022, the Company’s board of directors adopted the Rhythm Pharmaceuticals, Inc. 2022 Employment Inducement Plan or the Inducement Plan, without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Stock Market LLC listing rules or Rule 5635(c)(4). In accordance with Rule 5635(c)(4), awards under the Inducement Plan may only be made to a newly hired employee who has not previously been a member of the Company’s board of directors, or an employee who is being rehired following a bona fide period of non-employment by the Company or a subsidiary, as a material inducement to the employee’s entering into employment with the Company or its subsidiary. An aggregate of 1,000,000 shares of the Company’s common stock have been reserved for issuance under the Inducement Plan. The Company will continue to grant awards under the 2017 Plan pursuant to the terms thereof.
The exercise price of stock options granted under the Inducement Plan will not be less than the fair market value of a share of the Company’s common stock on the grant date. Other terms of awards, including vesting requirements, are determined by the Company’s board of directors and are subject to the provisions of the Inducement Plan. Stock options granted to employees generally vest over a four-year period but may be granted with different vesting terms. Certain options may provide for accelerated vesting in the event of a change in control. Stock options granted under the Inducement Plan expire no more than 10 years from the date of grant. As of the three months ended March 31, 2024, 553,889 stock option awards have been issued under the Inducement Plan. As of March 31, 2024, 281,196 restricted stock unit awards have been granted under the Inducement Plan. As of March 31, 2024, 164,915 shares of common stock are available for future grant under the Inducement Plan.
On January 4, 2024, the Company issued 432,143 shares of common stock as partial consideration for its acquisition of the worldwide rights to LGC’s proprietary compound LB54640.
11. Related-Party Transactions
Expenses paid directly to related parties for the three months ended March 31, 2024 and 2023, were $135 and $322, respectively. Outstanding payments due to related parties as of March 31, 2024 and December 31, 2023 were $5 and $1, respectively. See also Note 13, “Subsequent Events” for disclosure regarding transactions after March 31, 2024.
12. Long-Term Obligations
On June 16, 2022, we entered into a RIFA with entities managed by HealthCare Royalty Management, LLC, collectively referred to as the Investors. Pursuant to the RIFA and subject to customary closing conditions, the Investors have agreed to pay the Company an aggregate investment amount of up to $100,000, or the Investment Amount. Under the terms of the RIFA, we received $37,500 on June 29, 2022 upon FDA approval of IMCIVREE in BBS, referred to as the Initial Investment Amount, and we received an additional $37,500 on September 29, 2022 of the Investment Amount upon EMA approval for BBS. On September 12, 2023, we received the remaining $24,370 of the Investment Amount, net of debt issuance costs, following the achievement of a specified amount of cumulative net sales of IMCIVREE between July 1, 2022 and September 30, 2023.
As consideration for the Investment Amount and pursuant to the RIFA, we agreed to pay the Investors a tiered royalty on our annual net revenues, or Revenue Interest, including worldwide net product sales and upfront payments and milestones. The applicable tiered percentage will initially be 11.5% on annual net revenues up to $125,000, 7.5% on annual net revenues of between $125,000 and $300,000 and 2.5% on annual net revenues exceeding $300,000. If the Investors have not received cumulative minimum payments equal to 60% of the amount funded by the Investors to date by March 31, 2027, or 120% of the amount funded by the Investors to date by March 31, 2029, we must make a cash payment immediately following each applicable date to the Investors sufficient to gross the Investors up to such minimum amounts after giving full consideration of the cumulative amounts paid by us to the Investors through each date, referred to as the Under Performance Payment. As the repayment of the funded amount is contingent upon worldwide net product sales and upfront payments, milestones, and royalties, the repayment term may be shortened or extended depending on actual