Rhythm Amends Bivamelagon License with LG Chem: Lower Royalty Rate, $350M Fixed Payments

What happened

Rhythm Pharmaceuticals and LG Chem have amended the exclusive license agreement for bivamelagon, reducing the royalty rate on global net sales of Rhythm’s MC4R agonists—setmelanotide, bivamelagon, and RM-718—from low-to-mid single digits to a flat 1%. In exchange, Rhythm will pay LG Chem an additional $350 million in fixed payments spread over four years. This restructuring converts a variable, sales-based obligation into a fixed near-term cost, which is likely to increase Rhythm’s cash burn during a period when the company already faces significant operating losses. The amendment probably secures broader rights across the MC4R portfolio and may eliminate some future milestone payments, but the disclosed press release does not detail the full terms. Given Rhythm’s current cash position of approximately $416 million and annual net losses around $150 million, the added fixed payments could meaningfully shorten the cash runway unless offset by revenue growth or further financing.

Implication

The amended agreement lowers the long-term royalty burden on Rhythm’s MC4R franchise, which is positive if sales scale substantially, but the immediate $350 million fixed payment obligation is a significant addition to Rhythm’s cost structure. With only about $416 million in cash and expected operating expenses of $295–315 million for 2025, the company may need to raise capital sooner than previously anticipated, potentially diluting existing shareholders. The move likely reflects LG Chem’s preference for guaranteed payments over sales-based royalties, and while it may simplify economics if Rhythm’s products succeed, it removes flexibility during a high-risk launch period. Management may argue the amendment provides certainty and supports long-term value, but investors should scrutinize the exact payment schedule and any offsets from reduced milestones. Until Rhythm demonstrates clear revenue acceleration to cover these fixed obligations, the amendment is a mild negative for near-term cash flow and reinforces the WAIT rating.

Thesis delta

The amendment introduces a $350 million fixed payment obligation over four years, which increases Rhythm’s near-term cash needs and may accelerate dilution or require additional financing. However, the reduction in royalty rate from low-to-mid single digits to 1% lowers variable costs as revenue scales, potentially improving long-term margins if sales grow as expected. Overall, the change is slightly negative for cash runway in the next 12–24 months and does not alter the underlying thesis that Rhythm is a high-risk, high-reward biotech trading at a premium.