An Phase I/IIa Clinical Study to Evaluate the Safety/Tolerability, Pharmacokinetics and Preliminary Efficacy of INB301 Injection in Patients With Cancer Cachexia

The screening will be completed within 28 days before administration. Subjects who pass the screening will receive subcutaneous injection of INB301 until the investigator determines that the risk of continued treatment outweighs the benefit, toxicity becomes intolerable, or other criteria for withdrawal or treatment discontinuation are met, whichever occurs first. The end-of-study/early withdrawal visit will be completed at 28 days (±7 days) after the last dose.

If the anti-cancer treatment is suspended, modified, interrupted, or the protocol is changed during INB301 treatment, it is not considered a protocol deviation, and administration of INB301 will continue as specified in the protocol. Adjustments to standard of care, drug dosage or course of anti-cancer treatment, including treatment breaks, are at the discretion of the investigator.

Phase I dose escalation phase:

The dose escalation phase uses a standard 3+3 design to determine the maximum tolerated dose (MTD) or recommended expansion dose(RED). Enrolled subjects are sequentially assigned to 6 dose levels (50 mg, 100 mg, 200 mg, 300 mg, 400 mg, and 500 mg) to receive subcutaneous injection of INB301 every 3 weeks as a cycle. The starting dose of INB301 is based on a Minimum Anticipated Biological Effect Level (MABEL) approach, integrating nonclinical pharmacokinetic/pharmacodynamic (PK/PD) modeling, target engagement considerations, and available safety margins.

Phase I dose expansion phase:

In the dose expansion phase, the dose level (e.g., 200 mg, 400 mg) and dosing frequency will be determined based on the dose-escalation results, following discussion and consensus by the SMC, which is composed of the Investigator and the Sponsor. The RP2D will be confirmed during the dose expansion phase. It is tentatively planned to enroll 7-10 subjects per dose cohort.

Phase IIa:

After the RP2D is determined (e.g., 400 mg Q4W) based on the Phase I data, a cohort study in single tumor type with cachexia will be conducted to further evaluate the efficacy, safety, and tolerability of the investigational medicinal product.