Undisclosed receptor

The term "Undisclosed receptor" is a placeholder designation used by biotechnology and pharmaceutical companies to refer to a biological target whose specific identity is kept confidential to protect intellectual property or maintain a competitive advantage [1, 5]. This practice is common during early-stage drug discovery, preclinical development, and the initial phases of clinical trials [6, 11]. For example, the antibody-drug conjugate IM-1617 is described as targeting an undisclosed receptor tyrosine kinase that is overexpressed in various solid tumors [1, 6]. Similarly, the bispecific antibody BMS-986442 targets T-cell immunoreceptor with Ig and ITIM domains (TIGIT) alongside an undisclosed receptor expressed on T cells and natural killer cells [3]. Other examples include Voyager Therapeutics' "Receptor X," an undisclosed receptor on the blood-brain barrier used for transcytosis of viral vectors [7]. Because "Undisclosed receptor" is a generic descriptor rather than a specific molecule, its biological functions, molecular classifications, and disease roles are context-dependent and vary across different therapeutic programs [2, 8]. Consequently, it does not represent a single therapeutic target but rather a category of proprietary targets whose identities have not yet been publicly revealed [4, 9].

Other names

Undisclosed targetProprietary receptorReceptor X

The mechanism of action for drugs targeting an undisclosed receptor varies significantly depending on the specific program, ranging from antibody-drug conjugate (ADC) mediated cytotoxicity to immune system modulation or facilitated transport across the blood-brain barrier [1, 3, 7].