PT-141 dosage in clinical trials
The phase 3 RECONNECT trials used bremelanotide 1.75 mg by subcutaneous injection, as needed, for 24 weeks (Kingsberg et al., 2019). Earlier studies tested 0.3–10 mg subcutaneously in men and 7.5–20 mg intranasally. These are the doses the studies used, reported here for research reference only.
The dose studied most is 1.75 mg subcutaneous, the dose carried into the phase 3 RECONNECT trials after the phase 2b dose-finding work. In that phase 2 trial, women self-administered 0.75, 1.25 or 1.75 mg as desired over 12 weeks. The pooled 1.25/1.75 mg groups separated from placebo, and responder rates at 1.75 mg were significant on all seven endpoints. The blood pressure trial compared the same three doses. The largest pressure changes and the heart rate fall were at 1.75 mg.
Earlier male trials used a wider range. Rosen et al. gave 0.3 to 10 mg subcutaneously to healthy men, with significant erectile responses above 1.0 mg, and 4 or 6 mg to men with an inadequate response to Viagra.
The intranasal trials used much larger doses than the subcutaneous ones: 7.5 mg with sildenafil (Diamond et al., 2005), 10 mg in sildenafil non-responders (Safarinejad et al., 2008) and 20 mg single doses in women (Diamond et al., 2006). The gap between the nasal and injected amounts reflects the route; the abstracts do not give nasal bioavailability. Tasman does not publish dosing guidance. The table records only what each study used.
Doses used by each cited study
| Study | Model | Dose | Frequency | Duration |
|---|---|---|---|---|
| Kingsberg SA et al. 2019 | Human, phase 3 RCTs (premenopausal women, HSDD) | 1.75 mg subcutaneous | As needed | 24 weeks |
| Clayton AH et al. 2016 | Human, phase 2 dose-finding RCT (premenopausal women) | 0.75, 1.25 or 1.75 mg subcutaneous | As desired | 12 weeks |
| White WB et al. 2017 | Human, RCT with ambulatory BP monitoring (n=397 women) | 0.75, 1.25 or 1.75 mg subcutaneous | Two doses 24 h apart | Monitoring period around dosing |
| Rosen RC et al. 2004 | Human, phase 1/2 (healthy men; ED patients) | 0.3–10 mg subcutaneous (healthy); 4 or 6 mg (ED) | Single doses, crossover in ED patients | Not stated in the abstract |
| Diamond LE et al. 2005 | Human, crossover RCT (n=19 men with ED) | 7.5 mg intranasal with 25 mg sildenafil | Single dose per session | 6-hour post-dose assessment |
| Safarinejad MR et al. 2008 | Human, RCT (n=342 men, sildenafil non-responders) | 10 mg intranasal | 45 minutes to 2 hours before sexual stimulation; at least 16 attempts | Not stated in the abstract |
| Diamond LE et al. 2006 | Human, crossover RCT (n=18 premenopausal women, arousal disorder) | 20 mg intranasal | Single dose | 24-hour follow-up |
This table reports what each study used. It is not a recommendation or an instruction.
Vial maths
| Vial | BAC water | Concentration | Per 0.01 mL (1 unit, U-100) |
|---|---|---|---|
| 10 mg | 1 mL | 10 mg/mL | 100 mcg |
| 10 mg | 2 mL | 5 mg/mL | 50 mcg |
| 10 mg | 3 mL | 3.333 mg/mL | 33.3 mcg |