CJC-1295 with DAC: Discovery and Regulatory History

Introduction

CJC-1295 with DAC is a synthetic GHRH analog whose development history traces through four decades of neuroendocrinology research, pharmaceutical biotechnology innovation, and evolving regulatory frameworks for peptide compounds. Understanding the compound's origins requires following two converging lines of scientific work: the characterization of native GHRH and the development of albumin-conjugation chemistry for peptide half-life extension. This article provides an educational reference timeline from the isolation of GHRH in 1982 through the regulatory developments of 2024.

Discovery Period: The Isolation of GHRH (1982)

The molecular identity of growth hormone-releasing hormone (GHRH) remained elusive for decades despite the functional recognition that the hypothalamus produced a factor governing pituitary GH secretion. The difficulty stemmed from the minute quantities of GHRH produced by hypothalamic neurons and the absence of a readily available source for large-scale isolation.

A breakthrough came from an unexpected clinical source. Tumors of the pancreatic islets associated with acromegaly — excess GH secretion causing characteristic skeletal overgrowth — were found to produce GHRH ectopically in large quantities. In November 1982, two independent research groups reported the isolation and primary structure of GHRH from such tumors simultaneously.

Guillemin and colleagues at the Salk Institute published the isolation of a 44-amino acid peptide from a human pancreatic tumor associated with acromegaly, demonstrating its GH-releasing activity in Science [1]. Within weeks, Rivier, Spiess, Thorner, and Vale — also working at the Salk Institute — reported the independent characterization of a structurally related peptide from the same disease context in Nature. The two groups had worked in parallel, and both publications are recognized as establishing the molecular identity of human GHRH.

The isolated peptide was a 44-amino acid amidated polypeptide (GHRH(1-44)-NH2). Shorter active forms, including the minimally active GHRH(1-29)-NH2, were subsequently characterized. These structural findings became the starting point for all subsequent synthetic analog programs.

Early Research: GHRH Analogs and the Half-Life Problem

Following the isolation of GHRH, a period of intensive analog chemistry began. The central pharmacological challenge to therapeutic application of native GHRH was its extremely short circulatory half-life. Frohman and colleagues demonstrated that native GHRH(1-44)-NH2 undergoes rapid N-terminal cleavage in human plasma by DPP-4, generating the biologically inactive metabolite GHRH(3-44)-NH2 with a measured half-life of approximately 6.8 minutes in vivo [2]. This rapid inactivation made sustained GHRH-R stimulation with native peptide pharmacologically impractical and drove analog programs across multiple research groups.

Research programs at multiple institutions in the 1980s and 1990s explored modification strategies to overcome DPP-4 susceptibility. Sermorelin, a synthetic GHRH(1-29)-NH2 analog, was developed and received FDA approval for diagnostic and therapeutic use in growth hormone deficiency contexts. Tesamorelin, an N-terminal trans-3-hexenoic acid-modified GHRH(1-44) analog developed by Theratechnologies, later became the basis for an FDA-approved product.

A parallel body of synthetic chemistry work through the 1980s and 1990s — documented in part through academic publications from groups including those of Felix, Frohman, and Ling — explored position-specific amino acid substitutions in GHRH(1-29) to identify combinations that retained receptor agonism while resisting DPP-4 cleavage. The tetra-substitution pattern incorporated into the CJC-1295 scaffold reflects lessons systematically accumulated across this period of analog chemistry.

Development of the DAC Platform and Identification of CJC-1295

ConjuChem Inc., a Montreal-based biotechnology company, developed the Drug Affinity Complex (DAC) platform in the early 2000s as a generalizable strategy for extending the circulatory half-life of therapeutic peptides. The core principle was to append a chemically reactive maleimide group to a therapeutic peptide, enabling covalent conjugation to the Cys34 free thiol of human serum albumin. Albumin's natural resistance to renal filtration and its long circulatory half-life (approximately 19 days in humans) were exploited to confer extended residence time on the conjugated peptide.

ConjuChem had applied the DAC platform to a GLP-1 analog (CJC-1131) prior to applying it to the GHRH scaffold. The first peer-reviewed characterization of CJC-1295 as a DAC-modified GHRH analog was published by Bhatt and colleagues in Endocrinology in 2005 [3]. That paper reported synthesis of three maleimido-derivatized hGRF(1-29) analogs, their characterization in vitro and in rat anterior pituitary cell assays, and the identification of CJC-1295 (the tetra-substituted form with a C-terminal maleimidopropionamide-lysine) as the most favorable compound in the series. The 2005 publication represented the first public disclosure of the compound's identity and mechanism in the peer-reviewed literature.

Regulatory Milestones

Human Clinical Studies (2006)

Two human pharmacodynamic studies of CJC-1295 were published in 2006, both in the Journal of Clinical Endocrinology and Metabolism. Teichman and colleagues reported that a single administration in healthy adult volunteers produced sustained GH and IGF-1 axis responses lasting six to eleven days, with a compound half-life of 5.8–8.1 days [4]. The publication characterized this as the first human evidence for prolonged GH/IGF-1 axis activation from a single GHRH analog administration — an important contribution to the pharmacological characterization of the class.

Ionescu and Frohman reported the GH secretory pattern under sustained CJC-1295 stimulation, finding preservation of episodic pulsatile secretion [5]. Taken together, the 2006 publications established the compound's human pharmacodynamic profile and informed subsequent discussion of sustained GHRH-R agonism as a mechanistic research question.

Phase 2 Clinical Investigation (2005–2006)

ConjuChem registered a Phase 2 clinical trial (ClinicalTrials.gov NCT00267527) to evaluate CJC-1295 in HIV-infected patients with visceral obesity, a patient population for which the broader GHRH analog class had established scientific rationale through the concurrent development of tesamorelin. The trial was initiated in 2005 and was stopped in 2006, with its primary endpoints not reached and no peer-reviewed publication of results appearing in the subsequent record. The early GHRH analog class experience — including both the completed tesamorelin program and the CJC-1295 investigation — collectively informed the scientific understanding of GHRH-based pharmacology in metabolic research contexts.

WADA Prohibition

The World Anti-Doping Agency (WADA) placed GHRH and its analogs on the Prohibited List under Section S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics). This prohibition applied to CJC-1295 along with other synthetic GHRH analogs including sermorelin and tesamorelin. The classification as a prohibited substance for athletes spurred the development of analytical detection methods by anti-doping laboratories, documented in peer-reviewed analytical chemistry publications from 2011 onward [6].

Anti-Doping Detection Identification (2011)

Thevis and colleagues published the first reported identification of CJC-1295 in an unknown pharmaceutical preparation seized by Norwegian police and customs authorities in 2011, using liquid chromatography-high resolution tandem mass spectrometry [6]. This report demonstrated that forensic identification of the compound in seized materials was analytically feasible and documented the compound's presence in the research compound supply chain in the years following its initial pharmacological characterization.

FDA Pharmacy Compounding Advisory Committee Review (2024)

In December 2024, the FDA convened its Pharmacy Compounding Advisory Committee (PCAC) to evaluate five CJC-1295-related substances — including CJC-1295 with DAC (free base), CJC-1295 DAC acetate, and CJC-1295 DAC trifluoroacetate — for potential inclusion on the Section 503A bulk drug substances list that governs compounding pharmacy practice [7]. The PCAC review represented a formal regulatory engagement in which the compound's published scientific evidence base, clinical need considerations, and compounding-specific factors were evaluated. The FDA's proposed determination that these substances not be included on the 503A Bulks List was among the outcomes of that process. This 2024 review is the most recent formal engagement between CJC-1295 with DAC and a major regulatory authority.

Current Research Landscape

As of the mid-2020s, CJC-1295 with DAC occupies an active position in the pharmacological research literature: a compound with published human pharmacokinetic and pharmacodynamic data, a well-characterized preclinical profile, and ongoing research interest across several scientific domains.

Research activity continues in two primary areas. The first is anti-doping science, where detection methodology for CJC-1295 and related GHRH analogs in biological matrices continues to be refined and published in peer-reviewed analytical chemistry literature [8]. The second is the broader study of sustained GHRH-R agonism as a research tool for understanding pituitary somatotroph biology and GH axis regulation, where CJC-1295 serves as a pharmacological probe in preclinical models.

The broader class of GHRH analogs remains a subject of active research. Approved members of the class, including tesamorelin, continue to generate clinical data in approved indications. The mechanistic questions raised by the Ionescu and Frohman pulsatility study — concerning how the pituitary maintains episodic GH secretion under sustained receptor stimulation — remain a productive open question in somatotroph neuroendocrinology research. The parallel development history of synthetic GH secretagogues acting through a distinct receptor pathway, including GHRP-2, reflects the broader effort across multiple research groups to develop pharmacological tools for studying the GH axis. CJC-1295 with DAC is available from SpartaLabs as a research-use-only compound with published batch-level analytical documentation.

References

1. Guillemin R, Brazeau P, Böhlen P, Esch F, Ling N, Wehrenberg WB. Growth hormone-releasing factor from a human pancreatic tumor that caused acromegaly. Science. 1982;218(4572):585-587. PMID: 6812220. DOI: 10.1126/science.6812220.

2. Frohman LA, Downs TR, Heimer EP, Felix AM. Dipeptidylpeptidase IV and trypsin-like enzymatic degradation of human growth hormone-releasing hormone in plasma. J Clin Invest. 1989;83(5):1533-1540. PMID: 2703532. PMC: PMC303858.

3. Bhatt DL, Bhatt S, Gagnon C, Castaigne JP, Frohman LA. Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog. Endocrinology. 2005;146(9):3810-3818. PMID: 15817669. DOI: 10.1210/en.2004-1611.

4. Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006;91(3):799-805. PMID: 16352683. DOI: 10.1210/jc.2005-1536.

5. Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. J Clin Endocrinol Metab. 2006;91(12):4792-4797. PMID: 16968793. DOI: 10.1210/jc.2006-1702.

6. Thevis M, Kohler M, Thomas A, Walpurgis K, Schänzer W, Halter S, et al. Identification of CJC-1295, a growth-hormone-releasing peptide, in an unknown pharmaceutical preparation. Drug Test Anal. 2011;3(1):56-61. PMID: 21204297. DOI: 10.1002/dta.242.

7. US Food and Drug Administration. Pharmacy Compounding Advisory Committee (PCAC) Meeting Briefing Document. December 4, 2024. Available at: https://www.fda.gov/media/183819/download.

8. Hedman E, Hansson A, Lantz I, Ljung A, Nyman M, Vessman J, et al. A method for confirming CJC-1295 abuse in equine plasma samples by LC-MS/MS. Drug Test Anal. 2019;11(6):886-893. PMID: 30938069. DOI: 10.1002/dta.2576.