Dr. Spielmans, professor of psychology at Metropolitan State University in Saint Paul, Minn., examined data from the FDA application for bremelanotide, clinicaltrials.gov entries for two phase 3 trials of the drug, and a 2019 article published in Obstetrics & Gynecology that described results from the 24-week trials.
In Dr. Speilman’s analysis, which was published online March 7 in the Journal of Sex Research, he notes that 42.1% of trial participants who received bremelanotide did not complete the trial, compared with 20.48% of participants who received placebo.
Of those who completed the study, 87.22% who received placebo wanted to continue treatment in an open-label extension, compared with 69.97% who received bremelanotide, he wrote.
Women “should be aware of the small degree of bremelanotide’s efficacy, that the protocol-specified outcomes of bremelanotide are mostly unknown, and that participants would rather take a placebo than bremelanotide,” Dr. Spielmans said.
Anita H. Clayton, MD, an author of the Obstetrics & Gynecology paper addressed in Dr. Spielmans’ analysis, says the Journal of Sex Research article does not provide new information and is a disservice to women because it questions accurate scientific data.
Measuring outcomes in HSDD is an evolving field, Dr. Clayton, a psychiatrist at the University of Virginia in Charlottesville, said in an interview. Initial FDA guidance relied on satisfying sexual events as an outcome measure, but this measure was derived from erectile dysfunction studies and is not necessarily adequate for assessing HSDD, she said. The FDA and drug developers agreed to use the desire subscale of the Female Sexual Function Index (FSFI-D) as a coprimary outcome measure instead, she noted.
Dr. Spielmans’ critique of Obstetrics & Gynecology paper
The article published in Obstetrics & Gynecology reporting bremelanotide trial results was noteworthy, although the various issues involved can be seen in reports about other drug trials, Dr. Spielmans said in an interview.
“It is well-established that journal articles reporting clinical trial data overstate benefits and understate harms,” he continued. In this case, “the very incomplete data reporting, reliance on many post-hoc measures of questionable validity, hiding the concerning number of dropouts due to adverse events, and putting a positive spin on efficacy and tolerability is both remarkable and highly problematic,” Dr. Spielmans said.
Dr. Clayton’s reaction
Data about dropout rates due to adverse events have been reported and presented at national meetings, she said in an interview. In addition, a questionnaire found that bremelanotide was superior to placebo in terms of patients feeling that the treatment had provided clinically meaningful benefit, Dr. Clayton said.
The available information enables patients to make informed treatment decisions, Dr. Clayton continued. “There is really this sexist attitude of women needing protection from their own decisions,” she said.
Diagnosing and treating HSDD
Eight of 11 efficacy outcomes in the clinicaltrials.gov study protocols for bremelanotide were not reported in the Obstetrics & Gynecology article in a way that was consistent with the protocols, Dr. Spielmans said. Changing a coprimary outcome to the key secondary outcome “occurred over a year after the trials had begun,” and the authors of the journal article “did not mention that this change occurred,” Dr. Spielmans wrote.
For the coprimary outcome measures of mean change on FSFI-D and Female Sexual Distress Scale–Desire/Arousal/Orgasm #13, “bremelanotide offers modest benefits over placebo,” Dr. Spielmans reported.
In addition to outlining his concerns about transparency in the reporting of trial data and raising questions about the outcome measures used in the Obstetrics & Gynecology article, Dr. Spielmans wrote that the diagnosis of HSDD is problematic.
“The lack of specifying symptom duration, questionable validity for the lack of sexual fantasies as a diagnostic criterion, difficulty in disentangling individual sexual problems from relational problems, and the failure to consider cultural influence (including the pressure on women to satisfy the sexual desires of their male partners) in the experience of sexuality all render HSDD as a problematic entity,” Dr. Spielmans wrote.
The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders replaced HSDD and female sexual arousal disorder with the combined condition female sexual interest/arousal disorder. HSDD is in the 11th edition of the International Classification of Diseases and can be applied to men or women, Dr. Spielmans said.
FDA acknowledged HSDD as an unmet medical need
Dr. Clayton pointed out that HSDD was described decades ago and the FDA acknowledged it as an unmet medical need, and she expressed dissatisfaction with the fact the hypoactive sexual desire disorder appears with quotation marks around it in the title of Dr. Spielmans’ article. This way of presenting HSDD indicates that “the author has no concept of sexual health or sexual dysfunction,” Dr. Clayton said. “Basically this is sort of a dramatic tool, I think, to act like this is not a real disorder,” she added.
Carl Spana, PhD, CEO and president of Palatin Technologies, the developer of bremelanotide, defined the article in the Journal of Sex Research as a “retrospective meta-analysis, and not a re-analysis of the data.
“As a meta-analysis, it is open to various interpretations and reflects the author’s interpretations, which appear to have clear biases,” Dr. Spana said in an interview. “We believe several of this author’s interpretations are contrary to the FDA’s positive assessment that led to Vyleesi’s approval as a safe and effective treatment for women suffering from hypoactive sexual desire disorder.”
The author is unaware of the validation that was conducted at the direction of the FDA to establish clinically meaningful cutoffs for patient-reported outcomes and to establish metrics that define clinical benefit, Dr. Spana said
“Vyleesi was approved by the FDA after a thorough analysis of data from two well-controlled phase 3 clinical studies and multiple clinical and preclinical safety studies,” he said. “The analyses in the New Drug Application were prespecified and conducted according to a statistical analysis plan that the sponsor and FDA agreed to prior to database lock.”
Dr. Spielmans disclosed holdings in Vanguard Healthcare, a mutual fund that invests in pharmaceutical firms. Dr. Clayton has received financial support from Palatin and AMAG Pharmaceuticals, the companies that developed bremelanotide, in previous years.