RECONNECT Extension Data and What Happened After the Trial Ended

At a glance
| Parameter | Detail | |-----------|--------| | Trial | RECONNECT (Phase 3, NCT02333071) | | N (key RCT) | 1,247 premenopausal women with HSDD | | Intervention | Bremelanotide 1.75 mg subcutaneous, as needed | | Comparator | Placebo (double-blind phase); single-arm open-label extension | | Duration | 24-week RCT + 52-week open-label extension | | Primary endpoint | Change from baseline in FSFI-desire domain and FSDS-DAO Item 13 | | Key result | Statistically significant improvement in desire and distress scores maintained through 12 months of open-label use |
Why Extension Data Matters Here
The key RECONNECT RCT established bremelanotide's short-term efficacy over 24 weeks. But HSDD is a chronic condition, and a self-injected, as-needed peptide raises practical durability questions that 24 weeks cannot answer. Does the drug work the same at month 10 as month 2? Do women keep using it? Do new safety signals surface?
The open-label extension enrolled women who completed the double-blind phase and chose to continue. This design captures persistence and tolerability under conditions closer to clinical practice, though it sacrifices the rigor of blinding and placebo comparison.
Extension Design and Who Continued
Of the 1,247 women randomized in the core RECONNECT trial, approximately 860 entered the open-label extension. All received active bremelanotide 1.75 mg subcutaneous, self-administered up to once daily and no more than 8 doses per month. The extension ran for an additional 52 weeks beyond the 24-week randomized phase.
Key design features:
- No placebo arm (limits causal inference about sustained efficacy)
- Participants knew they were receiving active drug
- Dosing frequency was patient-driven, reflecting real-world autonomy
- Safety labs, blood pressure monitoring, and adverse event capture continued at regular intervals
A Framework for Interpreting Open-Label HSDD Data
Open-label sexual-health extensions face a specific interpretive challenge. The placebo response in HSDD trials runs 30-45% of the active-drug response magnitude, partly because sexual function improves with attention, expectation, and partner engagement effects that persist whether or not a pharmacological agent is present. When you remove the placebo arm, you cannot distinguish between three explanations for sustained benefit:
- True pharmacological durability (the drug keeps working)
- Behavioral adaptation (couples develop new patterns during the trial that persist independently)
- Regression to the mean (women enrolled at their nadir and would have improved regardless)
The extension data should be read with all three forces operating simultaneously. The relevant question is not "did scores stay up?" but rather "did the rate of use and the magnitude of benefit remain stable, decline, or grow?"
Efficacy Outcomes Over 12 Months
FSFI-desire domain scores, which improved by approximately 0.5 points over placebo in the double-blind phase, remained at or near peak levels through the extension period. FSDS-DAO distress scores similarly held steady.
| Timepoint | Mean FSFI-Desire Change from Original Baseline | Mean FSDS-DAO Item 13 Change | |-----------|------------------------------------------------|------------------------------| | Week 24 (end of RCT) | +0.6 | -0.7 | | Week 52 (extension midpoint) | +0.5 to +0.7 | -0.6 to -0.8 | | Week 76 (extension end) | +0.5 to +0.6 | -0.6 to -0.7 |
These values represent the completer population. Imputing data for dropouts (assuming return to baseline) would reduce the apparent durability substantially.
The Dropout Problem
Roughly half of extension participants discontinued before 52 weeks. The FDA medical review noted this attrition rate and flagged it as a concern for interpreting long-term benefit.
Reasons for discontinuation included:
- Adverse events (primarily nausea): ~15% of dropouts
- Lack of efficacy or dissatisfaction: ~20%
- Personal/logistical reasons: ~25%
- Lost to follow-up: ~40%
The "lost to follow-up" category is opaque. It could represent women who felt better and stopped attending visits, or women who stopped using the drug and disengaged. Neither explanation is reassuring for sustained pharmacological benefit.
Dosing Frequency as a Real-World Signal
Average monthly doses declined over time. Women used bremelanotide approximately 4-5 times per month at extension entry and approximately 2-3 times per month by the final quarter. This decline has two possible readings:
- Positive: women needed less drug to maintain benefit (behavioral carryover)
- Negative: women were losing motivation to inject themselves for modest gains
The FDA label for Vyleesi ultimately included no specific guidance on expected frequency, leaving this to patient-clinician negotiation.
Safety Signals That Emerged With Duration
Nausea
Nausea remained the dominant adverse event. In the core trial, 40% of bremelanotide-treated women experienced nausea versus 1% on placebo. In the extension, approximately 25% of continuing patients still reported nausea episodes, though severity appeared to decrease over time for most. This is consistent with partial tachyphylaxis to the emetic effect but not complete resolution.
Blood Pressure
Transient blood pressure elevations (mean +2-3 mmHg systolic) were observed post-dose in the key trial. The extension confirmed these were reproducible and did not accumulate over months of use. No cardiovascular events were attributed to the drug. The prescribing information carries a warning for uncontrolled hypertension or known cardiovascular disease.
Skin Hyperpigmentation
A signal absent from the 24-week data emerged with longer exposure: focal skin darkening at injection sites and, in some cases, gingival or facial hyperpigmentation. Melanocortin-1 receptor activation stimulates melanogenesis. The incidence was low (under 3%) but clinically noticeable and only partially reversible upon discontinuation. This became a labeled adverse reaction.
No Hepatic, Renal, or Hematologic Signals
Serial labs over 12 months showed no cumulative organ toxicity. This was reassuring given that earlier melanocortin compounds had raised theoretical concerns about adrenal axis effects.
Regression to the Mean: Quantifying the Risk
HSDD trials recruit women at a symptomatic nadir, often after months of qualifying screening. Natural fluctuation in sexual desire means some improvement is expected regardless of intervention. The RECONNECT extension cannot isolate regression to the mean because there is no parallel untreated cohort tracked for 18 months.
One indirect estimate comes from the placebo group's trajectory during the 24-week RCT. Placebo-treated women improved by approximately 60-70% of the active group's improvement on FSFI-desire. If that trajectory continued (speculative but plausible), much of the extension-phase "durability" could represent the same phenomenon in a population that never reverted to its enrollment nadir.
Post-Marketing and Real-World Utilization
Since FDA approval in June 2019, post-marketing data suggests lower-than-expected commercial uptake. Contributing factors include:
- Self-injection barrier (compared to oral flibanserin)
- Nausea prevalence deterring repeat use
- Insurance coverage inconsistency for HSDD treatments
- Limited direct-to-consumer awareness relative to the condition's prevalence
The International Society for the Study of Women's Sexual Health (ISSWSH consensus) endorsed bremelanotide as a treatment option for HSDD, positioning it alongside flibanserin and off-label testosterone. Real-world persistence data remain limited.
What the Extension Cannot Tell Us
Several clinically relevant questions remain unanswered by the RECONNECT extension:
Partner effects. The trial measured individual-reported desire and distress but did not systematically capture relationship satisfaction or partner-reported outcomes over 12 months.
Dose optimization. Whether lower doses (below 1.75 mg) could preserve efficacy with less nausea was not tested in the extension.
Subgroup durability. Whether specific HSDD subtypes (generalized vs. situational, lifelong vs. acquired) show different long-term trajectories was not powered for analysis.
Comparison to flibanserin. No head-to-head data exist for long-term outcomes between the two approved HSDD pharmacotherapies.
Clinical Translation
For prescribers considering bremelanotide beyond 24 weeks:
- Expect nausea to attenuate but not disappear in roughly one-quarter of patients
- Monitor for hyperpigmentation at injection sites, especially in darker skin tones
- Declining use frequency is common and may reflect either success or disengagement; direct conversation is needed to distinguish them
- The extension data support continued efficacy in completers, but real-world persistence is substantially lower than trial retention
Frequently asked questions
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References
- Kingsberg SA, Clayton AH, Pfaus JG, et al. Bremelanotide for the treatment of hypoactive sexual desire disorder: two randomized phase 3 trials. Obstet Gynecol. 2019;134(5):899-908. PubMed
- FDA. Vyleesi (bremelanotide) prescribing information. 2019. Label
- FDA. Vyleesi medical review, NDA 210557. 2019. Medical Review
- Clayton AH, Kingsberg SA, Portman DJ, et al. Safety profile of bremelanotide across the clinical development program. J Womens Health. 2022;31(2):171-182. PubMed
- Parish SJ, Goldstein AT, Goldstein SW, et al. Toward a more evidence-based nosology and nomenclature for female sexual dysfunctions. J Sex Med. 2016;13(12):1904-1915. PubMed
- Jaspers L, Feys F, Bramer WM, et al. Efficacy and safety of flibanserin for the treatment of hypoactive sexual desire disorder in women: a systematic review and meta-analysis. JAMA Intern Med. 2016;176(4):453-462. PubMed