CJC-1295 Side Effects: Delayed-Onset Adverse Events Explained

Do published studies describe delayed side effects?

Not in a way that defines a delayed-onset window. FDA found three published human studies, all of the DAC form, all in healthy volunteers [1]. The two Teichman trials were randomized, placebo-controlled, double-blind, ascending-dose studies lasting 28 and 49 days in adults aged 21 to 61 [2]. FDA's summary gives overall event rates for these trials and describes several events as transient [1]. Separately, ConjuChem withdrew CJC-1295 DAC from clinical trials in 2006 after a participant in a phase 2 trial in HIV lipodystrophy (192 enrolled) died; those data were never published [1].

What the published trials recorded

In Teichman study 1, 35 people received CJC-1295 and 7 received placebo. Injection-site reactions occurred in about 70% of treated participants, and headache in 63% versus 14% on placebo. Flushing, warmth and transient low blood pressure occurred in about 30% of treated subjects. Other events were transient diarrhea and transient dizziness with low blood pressure in two subjects [1]. In study 2, injection-site reactions occurred in all treated subjects. Most events were more common at 125 or 250 micrograms/kg, and no serious adverse reactions were reported [1][2].

In Ionescu and Frohman, healthy men given one 60 or 90 micrograms/kg injection had dose-dependent heart-rate increases and transient injection-site redness and tenderness; no serious adverse events were seen [1]. A week later, trough GH was about 7.5-fold higher, mean GH 46% and IGF-I 45% higher, with pulse frequency and size unchanged [3].

Why hormone effects last longer than the injection

After one subcutaneous injection, the estimated half-life was 5.8 to 8.1 days; mean GH rose 2- to 10-fold for 6 days or more, and mean IGF-I rose 1.5- to 3-fold for 9 to 11 days. After multiple doses, mean IGF-I stayed above baseline for up to 28 days [2]. The human data do not show whether that persistence causes delayed side effects or predicts when an event will occur [2].

Serious signals and unknowns

FDA's compounding-safety page lists CJC-1295 in its 'nominated but withdrawn' table, meaning it was in category 2 (significant safety risks) until the nominators withdrew. FDA's stated concerns remain posted, including 'serious adverse events associated with CJC-1295 including increased heart rate and systemic vasodilatory reaction' and that clinical data are limited [4]. FDA also said GH and IGF-I elevation carries approved-label risks such as glucose intolerance, diabetes, fluid retention and tumor growth concerns, and that the studies were short, small and mostly single-dose, so long-term safety is unknown [1].

For the participant who died in the phase 2 trial, FDA cites anecdotal news reports: chest discomfort 2 hours after an 11th weekly dose, an ECG showing an acute heart attack, and the attending physician's most likely explanation of undiagnosed coronary artery disease with plaque rupture. Because the data were never published, a causal link is neither shown nor excluded [1].