What MBX Biosciences, Inc. told the SEC could break it.

Constrained global supply of non-human primates (cynomolgus monkeys) for preclinical research, following reduced China exports, has driven scarcity and sharply higher pricing for a critical research model.

“This change in the world supply of a critical research model has resulted in increased demand from breeding farms principally located in Cambodia, Vietnam, and Mauritius Island, with a resultant marked increase in unit pricing.”

MBX's product candidates rely on APIs and raw materials exposed to China-based suppliers, U.S. tariffs on imports, and potential Chinese retaliatory trade measures.

“further tariffs may be imposed that could affect imports of APIs used in our product candidates, or our business may be adversely impacted by retaliatory trade measures taken by China or other countries, including restricted access to such raw materials used in our product candidates.”

CMS's December 2025 GLOBE (Part B) and GUARD (Part D) proposed rules would tie federal drug reimbursement to international MFN benchmark prices, exposing future MBX products to mandatory rebates.

“On December 19, 2025, CMS released two proposed rules that would incorporate MFN pricing principles into federal reimbursement for prescription drugs.”

MBX outsources all manufacturing of its product candidates (API and final drug product) to third-party CMOs and has no in-house manufacturing capability.

“Our current strategy is to outsource all manufacturing of our product candidates to third parties. We currently rely on and engage third-party manufacturers to provide all of the API and the final drug product formulation of all of our product candidates that are being used in our clinical trials and preclinical studies.”