Two-year efficacy and safety of relugolix combination therapy in women with endometriosis-associated pain: SPIRIT open-label extension study.

STUDY QUESTION: What is the efficacy and safety of long-term treatment (up to 2 years) with relugolix combination therapy (CT) in women with moderate to severe endometriosis-associated pain? SUMMARY ANSWER: For up to 2 years, treatment with relugolix CT improved menstrual and non-menstrual pain, dyspareunia, and function in women with endometriosis; after an initial decline of <1%, the mean bone mineral density (BMD) remained stable with continued treatment. WHAT IS KNOWN ALREADY: Endometriosis is a chronic condition characterized by symptoms of dysmenorrhea, non-menstrual pelvic pain (NMPP), and dyspareunia, which have a substantial impact on the lives of affected women, their partners, and families. SPIRIT 1 and 2 were phase 3, randomized, double-blind, placebo-controlled studies of once-daily relugolix CT (relugolix 40 mg, oestradiol 1 mg, norethisterone acetate 0.5 mg) in premenopausal women (age 18-50 years) with endometriosis and moderate-to-severe dysmenorrhea and NMPP. These trials demonstrated a significant improvement of dysmenorrhea, NMPP, and dyspareunia in women treated with relugolix CT, with minimal decline (<1%) in BMD versus placebo at 24 weeks. STUDY DESIGN, SIZE, DURATION: Patients participating in this open-label, single-arm, long-term extension (LTE) study of the 24-week SPIRIT pivotal studies (SPIRIT 1 and 2) received up to an additional 80 weeks of once-daily oral relugolix CT treatment between May 2018 and January 2023. PARTICIPANTS/MATERIALS, SETTING, METHODS: Premenopausal women with confirmed endometriosis and moderate to severe dysmenorrhea and NMPP who completed the 24-week pivotal studies (SPIRIT 1 and 2 trials; Giudice et al., 2022) and who met all entry criteria were eligible to enrol. Two-year results were analysed by treatment group based on original randomization in pivotal studies: relugolix CT, delayed relugolix CT (relugolix 40 mg monotherapy for 12 weeks, followed by relugolix CT), or placebo→relugolix CT (placebo for 24 weeks followed by relugolix CT). The primary endpoints of the LTE study were the proportion of dysmenorrhea and NMPP responders at Week 52 and Week 104/end-of-treatment (EOT). A responder was a participant who achieved a predefined, clinically meaningful reduction from baseline in Numerical Rating Scale (NRS) scores (0 = no pain, 10 = worst pain imaginable) for the specific pain type with no increase in analgesic use. The predefined clinically meaningful threshold for dysmenorrhea was 2.8 points and for NMPP was 2.1 points. Secondary efficacy endpoints included change from baseline in Endometriosis Health Profile-30 (EHP-30) pain domain scores, a measure of the effects of endometriosis-associated pain on daily activities (function), NRS scores for dysmenorrhea, NMPP, dyspareunia, and overall pelvic pain, and analgesic/opioid use. Safety endpoints included adverse events and changes in BMD. MAIN RESULTS AND THE ROLE OF CHANCE: Of 1261 randomized patients, 1044 completed the pivotal studies, 802 enrolled in the LTE, 681 completed 52 weeks of treatment, and 501 completed 104 weeks of treatment. Demographics and baseline characteristics of the extension population were consistent with those of the original randomized population. Among patients randomized to relugolix CT at pivotal study baseline who continued in the LTE (N = 277), sustained improvements in endometriosis-associated pain were demonstrated through 104 weeks. The proportion of responders at Week 104/EOT for dysmenorrhea and NMPP was 84.8% and 75.8%, respectively. Decreases in dyspareunia and improvement in function assessed by EHP-30 pain domain were also sustained over 2 years. At Week 104/EOT, 91% of patients were opioid-free and 75% of patients were analgesic-free. Relugolix CT over 104 weeks was well tolerated with a safety profile consistent with that observed over the first 24 weeks. After initial least squares mean BMD loss <1% at Week 24, BMD plateaued at Week 36 and was sustained for the duration of 104 weeks of treatment. Efficacy and safety results were generally consistent in women in the placebo→relugolix CT and delayed relugolix CT groups. LIMITATIONS, REASONS FOR CAUTION: The study was conducted as an open-label study without a control group over the 80 weeks of the extension period. Of the 802 patients who were enrolled in this LTE study, 681 patients (84.9%) and 501 patients (62.5%) of patients completed 52 and 104 weeks of treatment, respectively. In addition, there currently are no comparative data to other hormonal medications. Finally, a third (37.4%) of the study population terminated participation early. WIDER IMPLICATIONS OF THE FINDINGS: In conclusion, relugolix CT offers an additional option to help address an important unmet clinical need for effective, safe, and well-tolerated medical treatments for endometriosis that can be used longer-term, reducing the need for opioids and improving quality of life. The findings from this study may help support the care of women with endometriosis seeking longer-term effective medical management of their symptoms. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by Myovant Sciences GmbH (now Sumitomo Pharma Switzerland GmbH). C.M.B. reports fees from Myovant, grants from Bayer Healthcare, fees from ObsEva, and Chair of ESHRE Endometriosis Guideline Group (all funds went to the University of Oxford); N.P.J. reports personal fees from Myovant Sciences, during the conduct of the study, personal fees from Guerbet, personal fees from Organon, personal fees from Roche Diagnostics; S.A.-S. reports personal fees from Myovant Sciences, personal fees from Bayer, personal fees from Abbvie, personal fees from UpToDate; J.S.P., and R.B.W. are employees and shareholders of Myovant Sciences; J.C.A.F. and S.J.I. are shareholders of Myovant Sciences (but at time of publicaion are no longer employess of Myovant Sciences); M.S.A. and K.W. have no conflicts to declare; V.M. is a consultant to Myovant; L.C.G. reports personal fees from Myovant Sciences, Inc and Bayer. The authors did not receive compensation for manuscript writing, review, and revision. TRIAL REGISTRATION NUMBER: NCT03654274.

A Plain Language Summary to learn about relugolix combination therapy for the treatment of pain associated with endometriosis.

WHAT IS THIS SUMMARY ABOUT?: This is a summary of research studies (known as clinical trials) called SPIRIT 1 and SPIRIT 2. The SPIRIT 1 and SPIRIT 2 studies compared how well a medicine called relugolix combination therapy worked in relieving pain in women with moderate to severe endometriosis compared to a placebo, a pill with no active medication. Endometriosis occurs when tissue similar to what normally lines the uterus grows in other places, such as the ovaries, fallopian tubes, and bowels. WHAT WERE THE RESULTS?: Researchers looked at 1261 adult women with moderate to severe endometriosis. Randomly, 420 (33%) of these women were assigned to relugolix combination therapy, 420 (33%) were assigned to delayed relugolix combination therapy (relugolix alone first and then relugolix combination therapy for the remainder of the study), and 421 (33%) were assigned to placebo. The SPIRIT 1 and SPIRIT 2 studies showed that more women taking relugolix combination therapy (75% from SPIRIT 1 and 75% from SPIRIT 2) for 24 weeks had both less pelvic or groin pain during menstrual periods from endometriosis and no need for more pain medicines than women who took placebo (27% from SPIRIT 1 and 30% from SPIRIT 2). The SPIRIT 1 and SPIRIT 2 studies also showed that more women taking relugolix combination therapy (59% from SPIRIT 1 and 66% from SPIRIT 2) for 24 weeks had both less pelvic or groin pain between menstrual periods from endometriosis and no need for more pain medicines than women who took placebo (40% from SPIRIT 1 and 43% from SPIRIT 2). Women taking relugolix combination therapy had less pelvic or groin pain during and between menstrual periods within 4 weeks of starting the medicine. The most common side effects were headaches, the common cold, and hot flushes or feeling hot among women taking relugolix combination therapy, delayed relugolix combination therapy, and placebo. Relugolix combination therapy was considered safe for those with no major medical problems. Women taking relugolix combination therapy had little to no loss of bone mineral density (a way of knowing how strong bones are) after 24 weeks of treatment. WHAT DO THE RESULTS OF THESE STUDIES TELL US?: Women with moderate to severe endometriosis taking relugolix combination therapy had much less pain from endometriosis than women taking placebo. Clinical Trial Registration: NCT03204318 (SPIRIT-1); NCT03204331 (SPIRIT-2) (ClinicalTrials.gov).

LIBERTY randomized withdrawal study: relugolix combination therapy for heavy menstrual bleeding associated with uterine fibroids.

BACKGROUND: In the pivotal LIBERTY 1 and 2 trials and long-term extension study, once-daily relugolix combination therapy (40 mg relugolix, 1 mg estradiol, 0.5 mg norethindrone acetate) reduced menstrual blood loss volume and pain among women with uterine fibroids. Relugolix combination therapy was well tolerated with preservation of bone mineral density through 52 weeks. OBJECTIVE: This study aimed to report the 2-year relugolix combination therapy efficacy and safety results of the phase 3 LIBERTY randomized withdrawal study. STUDY DESIGN: Women with uterine fibroid-associated heavy menstrual bleeding who completed the 24-week LIBERTY 1 or 2 trials, followed by the 28-week long-term extension study (up to 52 weeks total treatment), and who met the responder criteria (menstrual blood loss volume <80 mL and ≥50% reduction from pivotal study baseline at week 48 [week 24 of long-term extension]) were randomized in a 1:1 ratio to either blinded treatment with relugolix combination therapy or placebo for 52 weeks (total treatment period, 104 weeks). For women who had a relapse of heavy menstrual bleeding during the study (menstrual blood loss volume ≥80 mL), open-label relugolix combination therapy was offered. The primary endpoint was the proportion of women who maintained menstrual blood loss volume <80 mL through week 76 (week 24 of randomized withdrawal study). Secondary endpoints included time to menstrual blood loss volume ≥80 mL, proportion of women who maintained a menstrual blood loss volume of <80 mL through week 104 (over the 52-week randomized treatment period), the proportion of women who achieved or maintained amenorrhea at week 76 at the end of treatment, and the change in Uterine Fibroid Symptom-Quality of Life Bleeding and Pelvic Discomfort Scale and symptom severity scores. Analyses were performed for the modified intent-to-treat population, including all randomized women who received ≥1 dose of the study drug. RESULTS: Of the 229 randomized women (relugolix combination therapy, n=115; placebo, n=114), 228 received the study drug and 175 (76.7%) completed the randomized withdrawal study. Through week 76, 78.4% of women on relugolix combination therapy maintained menstrual blood loss volume <80 mL vs 15.1% in the placebo group (difference, 63.4%; 95% confidence interval, 52.9%-73.9%; P<.0001). At week 104, 69.8% of women on relugolix combination therapy maintained menstrual blood loss volume <80 mL vs 11.8% in the placebo group (difference, 58.0%; 95% confidence interval, 47.0%-69.1%; P<.0001). Through week 104, 88.3% of women on placebo relapsed with heavy menstrual bleeding (median time to relapse, 5.9 weeks). Among the 89 women in the placebo group who relapsed and received open-label rescue treatment, 87 women responded to relugolix combination therapy with a menstrual blood loss volume <80 mL. The proportion of women who achieved or maintained amenorrhea were 57.4% vs 13.3% at week 76 (difference, 44.1%; 95% confidence interval, 33.10%-55.1%; P<.0001) and 58.3% vs 10.6% at week 104 (difference, 47.6%; 95% confidence interval, 37.0%-58.3%; nominal P<.0001) for relugolix combination therapy and the placebo group, respectively. Relugolix combination therapy was generally well tolerated; no new safety signals were identified, and the adverse event profile over the second year was consistent with that reported through the first year of treatment. Bone mineral density remained stable in women who received relugolix combination therapy from week 52 to week 104. In women continuously treated with relugolix combination therapy up to 2 years, bone mineral density was generally preserved. CONCLUSION: After 2 years of treatment with relugolix combination therapy, there was evidence of durability of the effect in maintaining low menstrual blood loss volume in women with symptomatic uterine fibroids. Most women had return of heavy menstrual bleeding and associated symptoms after treatment cessation, which improved upon retreatment with relugolix combination therapy. Relugolix combination therapy was well tolerated, the adverse event profile remained consistent, and the mean bone mineral density was generally preserved through 2 years of treatment.

Relugolix combination therapy in European women with symptomatic uterine fibroids: a subgroup analysis from the randomized phase 3 LIBERTY pivotal trials.

OBJECTIVE: In the 24-week, phase 3 LIBERTY 1 (L1) and LIBERTY 2 (L2) trials, relugolix combination therapy (relugolix-CT (relugolix 40 mg, estradiol 1 mg, norethisterone acetate 0.5 mg)) reduced uterine fibroid (UF)-associated symptoms. This post hoc analysis assessed safety and efficacy of relugolix-CT in European women from L1/L2. METHODS: Premenopausal women (aged 18-50 years) with UF-associated heavy menstrual bleeding (HMB) were randomized 1:1:1 in L1 (N = 388) and L2 (N = 382) to relugolix-CT or placebo for 24 weeks, or delayed relugolix-CT (relugolix 40 mg then relugolix-CT; 12 weeks each). Primary endpoint: proportion of responders (menstrual blood loss (MBL) <80 mL and reduction of ≥50% from baseline MBL volume) over the last 35 days of treatment. Secondary endpoints: MBL volume, amenorrhea, UF-associated pain, symptom severity, distress related to bleeding and pelvic discomfort, health-related quality of life (HRQoL). Safety endpoints included adverse event (AE) reporting and bone mineral density (BMD) assessment. RESULTS: In European women from L1/L2 (N = 124, 16%), a significantly greater proportion of treatment responders was observed with relugolix-CT vs. placebo (85.4% vs. 19.1%, respectively; nominal p < .0001). There were statistically significant improvements with relugolix-CT vs. placebo for several secondary endpoints: reduction in MBL volume, amenorrhea rate, proportion achieving mild-to-no pain, reduction in symptom severity and distress from bleeding and pelvic discomfort, and improvement in HRQoL. Incidence of AEs and percentage changes in BMD from baseline to week 24 were similar for relugolix-CT and placebo. CONCLUSIONS: In European women with UF and HMB, once-daily relugolix-CT vs. placebo improved UF-associated symptoms and preserved BMD.

A plain language summary of the long-term relugolix combination therapy study for uterine fibroids.

What is this summary about? This is a summary of a research study (known as a clinical trial) called the LIBERTY extension study. The LIBERTY extension study is a long-term study looking at how well a medicine called relugolix combination therapy worked in reducing blood loss during menstrual periods in women with uterine fibroids with heavy menstrual periods. Women were included in the extension study if they finished the 24-week LIBERTY 1 or LIBERTY 2 studies. Heavy menstrual periods were considered to be menstrual blood loss of about one-third of a cup of blood (80 ml) per cycle for two cycles or about two-thirds of a cup of blood (160 ml) during one cycle. The LIBERTY extension study also looked at whether relugolix combination therapy was safe to take for up to 1 year. What were the results? Out of 770 total women with uterine fibroids with heavy menstrual bleeding who took part in the LIBERTY 1 and LIBERTY 2 studies, 476 took part in the LIBERTY extension study. From the start of the LIBERTY 1 and LIBERTY 2 studies through the end of the LIBERTY extension: 163 women took relugolix combination therapy for 52 weeks 149 women took relugolix alone for 12 weeks followed by relugolix combination therapy for 40 weeks 164 women took placebo for 24 weeks followed by relugolix combination therapy for 28 weeks The LIBERTY extension study showed that most women in all three treatment groups responded to relugolix combination therapy by having less bleeding during their menstrual periods, having improved anemia symptoms, and having stable bone mineral loss. Side effects were similar across treatment groups, and the most common side effects were headaches and hot flushes. What do the results mean? Women with uterine fibroids with heavy menstrual bleeding taking relugolix combination therapy may have fewer uterine fibroid bleeding symptoms for up to 1 year of treatment. Clinical Trial Registration: NCT03049735 (ClinicalTrials.gov) (LIBERTY 1) Clinical Trial Registration: NCT03103087 (ClinicalTrials.gov) (LIBERTY 2) Clinical Trial Registration: NCT03412890 (ClinicalTrials.gov) (LIBERTY extension study).

A plain language summary of the safety of relugolix combination therapy and improvement in symptoms in women with uterine fibroids from the LIBERTY 1 and LIBERTY 2 studies.

WHAT IS THIS SUMMARY ABOUT?: This is a summary of research studies (known as clinical trials) called LIBERTY 1 and LIBERTY 2. The LIBERTY 1 and LIBERTY 2 studies looked at how well a medication called relugolix combination therapy worked to reduce heavy bleeding at the time of menstruation compared with placebo. The studies also looked at what side effects were reported in women with uterine fibroids and heavy menstrual bleeding. WHAT WERE THE RESULTS?: Researchers looked at 388 adult women in the LIBERTY 1 study and 382 adult women in the LIBERTY 2 study. All women had heavy menstrual bleeding with uterine fibroids before the start of the LIBERTY 1 and LIBERTY 2 studies. The women were given one of three treatments during the studies: relugolix combination therapy or placebo for 24 weeks, or delayed relugolix combination therapy (relugolix alone for the first 12 weeks, then relugolix combination therapy for the last 12 weeks of the studies). More women taking relugolix combination therapy in the LIBERTY 1 study (73%) and LIBERTY 2 study (71%) had menstrual blood loss of less than one-third of a cup (80 mL) and had reduction of at least 50% less blood loss during their last menstrual period after 24 weeks of taking the medicine compared with placebo (LIBERTY 1: 19% and LIBERTY 2: 15%). The women taking relugolix combination therapy also had less pain than those taking placebo. Side effects were similar across treatment groups. Headaches and hot flushes were the most common side effects. WHAT DO THE RESULTS MEAN?: More women with uterine fibroids taking relugolix combination therapy for 24 weeks were likely to have fewer uterine fibroid symptoms than women receiving placebo. Clinical Trial Registration: NCT03049735 (LIBERTY 1); NCT03103087 (LIBERTY 2).

Quality of life with relugolix combination therapy for uterine fibroids: LIBERTY randomized trials.

BACKGROUND: Symptomatic uterine fibroids are burdensome to live with; they are associated with symptom-related distress, affect daily activities, and reduce health-related quality of life. The LIBERTY randomized clinical trials showed that oral relugolix combination therapy (40 mg relugolix, 1 mg estradiol, and 0.5 mg norethindrone acetate once daily) markedly improved fibroid-associated symptoms and conditions, including heavy menstrual bleeding, pain, and anemia, and was well-tolerated. OBJECTIVE: This study aimed to evaluate the effect of relugolix combination therapy on the symptom burden and health-related quality of life among women with uterine fibroids. STUDY DESIGN: Two replicate, multinational, double-blind, 24-week, randomized, placebo-controlled, phase 3 studies, LIBERTY 1 and LIBERTY 2, were conducted in premenopausal women with uterine fibroid-associated heavy menstrual bleeding (≥80 mL per cycle for 2 cycles or ≥160 mL during 1 cycle). The symptom burden and health-related quality of life were secondary endpoints and were assessed using the validated Uterine Fibroid Symptom and Quality of Life questionnaire, which the participants completed at baseline and at week 12 and 24 of treatment. For this secondary analysis, the pooled LIBERTY 1 and LIBERTY 2 data set was used. The Uterine Fibroid Symptom and Quality of Life questionnaire is made up of a Symptom Severity scale and a Health-Related Quality of Life scale, the latter of which includes 6 subscales focusing on the following aspects of daily life: concern, activities, energy or mood, control, self-consciousness, and sexual function. The Revised Activities subscale of the Health-Related Quality of Life scale addresses the impact of uterine fibroids on physical and social activities. Symptom burden was also assessed via the Bleeding and Pelvic Discomfort subscale, a patient-reported outcome measure derived from the Uterine Fibroid Symptom Severity scale that focuses on distress from key uterine fibroid symptoms, which was a key secondary endpoint. Least squares mean changes from baseline to week 24 in the Symptom Severity scale, Bleeding and Pelvic Discomfort subscale, overall Health-Related Quality of Life scale, and the respective subscales were compared between the relugolix combination therapy and placebo groups. Responder analyses of the proportion of women who experienced a clinically meaningful change from baseline to week 24 were conducted for the Bleeding and Pelvic Discomfort and the activity subscales. A stratified Cochran-Mantel-Haenszel test, adjusted for stratification factors (region [North America vs rest of world] and baseline menstrual blood loss volume), was used for treatment comparisons. RESULTS: Across both trials, 509 women were randomized to the relugolix combination therapy or placebo groups (April 2017-December 2018). Participants on relugolix combination therapy showed a statistically significant reduction in symptom severity (-33.5 vs -12.1; nominal P<.0001) and the Bleeding and Pelvic Discomfort subscale from baseline to week 24 when compared with those on placebo treatment (-48.4 vs -17.4; nominal P<.0001). Overall, the total Health-Related Quality of Life scores improved significantly from baseline to week 24 in the relugolix combination therapy group when compared with the placebo (+37.6 vs +13.1; nominal P<.0001). Responder analyses demonstrated that more women treated with relugolix combination therapy reported a clinically meaningful reduction in the Bleeding and Pelvic Discomfort subscale and an improvement in physical and social activities when compared with those treated with the placebo (nominal P<.0001). CONCLUSION: After 24 weeks of treatment with relugolix combination therapy, women with symptomatic uterine fibroids experienced substantial improvements in health-related quality of life with all subscales showing improvement, including emotional well-being, physical and social activities, and sexual function. In addition, women reported substantial reductions in the overall symptom burden and distress caused by key fibroid-associated symptoms.

Long-term Relugolix Combination Therapy for Symptomatic Uterine Leiomyomas.

OBJECTIVE: In the LIBERTY 1 and LIBERTY 2 placebo-controlled trials, once-daily relugolix combination therapy reduced menstrual blood loss volume and pain in women with heavy menstrual bleeding associated with uterine leiomyomas and was well tolerated, with preservation of bone mineral density (BMD) through 24 weeks. Here we report the long-term efficacy and safety of relugolix combination therapy treatment for up to 52 weeks. METHODS: Women with uterine leiomyoma-associated heavy menstrual bleeding who completed any treatment arm in either the LIBERTY 1 or LIBERTY 2 trial were eligible to enroll in a 28-week long-term extension study. All participants received once-daily relugolix combination therapy (40 mg relugolix, estradiol 1 mg, norethindrone acetate 0.5 mg) in the extension study. The primary efficacy endpoint was the proportion of women who achieved or maintained a menstrual blood loss volume of less than 80 mL and a 50% or greater reduction in menstrual blood loss volume from LIBERTY study baseline to the last 35 days of treatment (defined as responders ). Analyses were conducted for all three randomized treatment groups from pivotal studies. RESULTS: Overall, 477 women enrolled, 476 were treated, and 363 (76.1%) completed 52 weeks. Among patients treated with relugolix combination therapy through 52 weeks (n=163), sustained improvement in heavy menstrual bleeding was observed in 87.7% (responders). The least squares mean menstrual blood loss volume reduction was 89.9%, with 70.6% of patients achieving amenorrhea. At week 52, 59.0% of patients with anemia at baseline had improvements in hemoglobin concentration of greater than 2 g/dL. Distress due to uterine leiomyoma-associated symptoms measured by the BPD (Bleeding and Pelvic Discomfort) scale score was reduced by 51.3 points. Sustained reductions in uterine and uterine leiomyoma volume were observed. Bone mineral density was preserved through week 52. CONCLUSION: Improvements in heavy menstrual bleeding and anemia and reduction of uterine leiomyoma-associated symptom burden were sustained through up to 52 weeks of treatment with relugolix combination therapy in women with uterine leiomyomas. No new safety concerns were identified, and BMD was maintained. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT03049735; NCT03103087; NCT03412890. FUNDING SOURCE: Myovant Sciences GmbH.

Relugolix Combination Therapy for Uterine Leiomyoma-Associated Pain in the LIBERTY Randomized Trials.

OBJECTIVE: To assess the effect of once-daily relugolix combination therapy (relugolix-CT: relugolix 40 mg, estradiol 1 mg, and norethindrone acetate 0.5 mg) compared with placebo on moderate-to-severe pain in women with uterine leiomyomas and heavy menstrual bleeding. METHODS: Two replicate, multinational, double-blind, 24-week, randomized, phase 3 studies (LIBERTY 1 and 2) were conducted in premenopausal women with uterine leiomyoma-associated heavy menstrual bleeding (80 mL or greater per cycle for two cycles or 160 mL or greater during one cycle). A predefined secondary objective was to determine the effect of relugolix-CT on moderate-to-severe uterine leiomyoma-associated pain in the pain subpopulation (women with maximum pain scores of 4 or higher on the 0-10 numerical rating scale at baseline, with pain score reporting compliance of 80% (ie, 28 days or more over the last 35 days of treatment). This key secondary endpoint was defined as the proportion of women achieving minimal-to-no uterine leiomyoma-associated pain (maximum numerical rating scale score 1 or lower) at week 24; menstrual and nonmenstrual pain were evaluated in prespecified secondary analyses. Treatment comparisons were performed in the pooled LIBERTY 1 and 2 pain subpopulation using the Cochran-Mantel-Haenszel test stratified by baseline menstrual blood loss volume. RESULTS: Across both trials, 509 women were randomized to relugolix-CT or placebo (April 2017-December 2018). Of these, 277 (54.4%) met pain subpopulation requirements. With relugolix-CT, 45.2% (95% CI 36.4-54.3) of women achieved minimal-to-no pain compared with 13.9% (95% CI 8.8-20.5) with placebo (nominal P<.001). The proportions of women with minimal-to-no pain during menstrual days and during nonmenstrual days were significantly higher with relugolix-CT (65.0% [95% CI 55.6-73.5] and 44.6% [95% CI 32.3-57.5], respectively) compared with placebo (19.3% [95% CI 13.2-26.7], nominal P<.001, and 21.6% [95% CI 12.9-32.7], nominal P=.004, respectively). CONCLUSION: Over 24 weeks, relugolix-CT significantly reduced moderate-to-severe uterine leiomyoma-associated pain with a more pronounced effect on menstrual pain. These data support that relugolix-CT had clinically meaningful effects on women's experience of uterine leiomyoma-associated pain. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: LIBERTY 1, NCT03049735; LIBERTY 2, NCT03103087. FUNDING SOURCE: Myovant Sciences GmbH.

Once daily oral relugolix combination therapy versus placebo in patients with endometriosis-associated pain: two replicate phase 3, randomised, double-blind, studies (SPIRIT 1 and 2).

BACKGROUND: Endometriosis is a common cause of pelvic pain in women, for which current treatment options are suboptimal. Relugolix, an oral gonadotropin-releasing hormone receptor antagonist, combined with estradiol and a progestin, was evaluated for treatment of endometriosis-associated pain. METHODS: In these two replicate, phase 3, multicentre, randomised, double-blind, placebo-controlled trials at 219 community and hospital research centres in Africa, Australasia, Europe, North America, and South America, we randomly assigned women aged 18-50 years with surgically or directly visualised endometriosis with or without histological confirmation, or with histological diagnosis alone. Participants were eligible if they had moderate to severe endometriosis-associated pain and, during the 35-day run-in period, a dysmenorrhoea Numerical Rating Scale (NRS) score of 4·0 or higher on two or more days and a mean non-menstrual pelvic pain NRS score of 2·5 or higher, or a mean score of 1·25 or higher that included a score of 5 or more on 4 or more days. Women received (1:1:1) once-daily oral placebo, relugolix combination therapy (relugolix 40 mg, estradiol 1 mg, norethisterone acetate 0·5 mg), or delayed relugolix combination therapy (relugolix 40 mg monotherapy followed by relugolix combination therapy, each for 12 weeks) for 24 weeks. During the double-blind randomised treatment and follow-up period, all patients, investigators, and sponsor staff or representatives involved in the conduct of the study were masked to treatment assignment. The co-primary endpoints were responder rates at week 24 for dysmenorrhoea and non-menstrual pelvic pain, both based on NRS scores and analgesic use. Efficacy and safety were analysed in the modified intent-to-treat population (randomised patients who received ≥1 study drug dose). The studies are registered at ClinicalTrials.gov (SPIRIT 1 [NCT03204318] and SPIRIT 2 [NCT03204331]) and EudraCT (SPIRIT 1 [2017-001588-19] and SPIRIT 2 [2017-001632-19]). Eligible patients who completed the SPIRIT studies could enrol in a currently ongoing 80-week open-label extension study (SPIRIT EXTENSION [NCT03654274, EudraCT 2017-004066-10]). Database lock for the on-treatment duration has occurred, and post-treatment follow-up for safety, specificially for bone mineral density and menses recovery, is ongoing at the time of publication. FINDINGS: 638 patients were enrolled into SPIRIT 1 and randomly assigned between Dec 7, 2017, and Dec 4, 2019, to receive relugolix combination therapy (212 [33%]), placebo (213 [33%]), or relugolix delayed combination therapy (213 [33%]). 623 patients were enrolled into SPIRIT 2 and were randomly assigned between Nov 1, 2017 and Oct 4, 2019, to receive relugolix combination therapy (208 [33%]), placebo (208 [33%]), or relugolix delayed combination therapy (207 [33%]). 98 (15%) patients terminated study participation early in SPIRIT 1 and 115 (18%) in SPIRIT 2. In SPIRIT 1, 158 (75%) of 212 patients in the relugolix combination therapy group met the dysmenorrhoea responder criteria compared with 57 (27%) of 212 patients in the placebo group (treatment difference 47·6% [95% CI 39·3-56·0]; p<0·0001). In SPIRIT 2, 155 (75%) of 206 patients in the relugolix combination therapy group were dysmenorrhoea responders compared with 62 (30%) of 204 patients in the placebo group (treatment difference 44·9% [95% CI 36·2-53·5]; p<0·0001). In SPIRIT 1, 124 (58%) of 212 patients in the relugolix combination therapy group met the non-menstrual pelvic pain responder criteria versus 84 (40%) patients in the placebo group (treatment difference 18·9% [9·5-28·2]; p<0·0001). In SPIRIT 2, 136 (66%) of 206 patients were non-menstrual pelvic pain responders in the relugolix combination therapy group compared with 87 (43%) of 204 patients in the placebo group (treatment difference 23·4% [95% CI 13·9-32·8]; p<0·0001). The most common adverse events were headache, nasopharyngitis, and hot flushes. There were nine reports of suicidal ideation across both studies (two in the placebo run-in, two in the placebo group, two in the relugolix combination therapy group, and three in the delayed relugolix combination therapy group). No deaths were reported. Least squares mean percentage change in lumbar spine bone mineral density in the relugolix combination therapy versus placebo groups was -0·70% versus 0·21% in SPIRIT 1 and -0·78% versus 0·02% in SPIRIT 2, and in the delayed relugolix combination group was -2·0% in SPIRIT 1 and -1·9% in SPIRIT 2. Decreases in opioid use were seen in treated patients as compared with placebo. INTERPRETATION: Once-daily relugolix combination therapy significantly improved endometriosis-associated pain and was well tolerated. This oral therapy has the potential to address the unmet clinical need for long-term medical treatment for endometriosis, reducing the need for opioid use or repeated surgical treatment. FUNDING: Myovant Sciences.

Treatment of Uterine Fibroid Symptoms with Relugolix Combination Therapy.

BACKGROUND: Uterine fibroids are a common cause of heavy menstrual bleeding and pain. Treatment with the combination of relugolix (an oral gonadotropin-releasing hormone-receptor antagonist), estradiol, and norethindrone acetate, administered once daily, may have efficacy in women with uterine fibroids and heavy bleeding while avoiding hypoestrogenic effects. METHODS: We conducted two replicate international, double-blind, 24-week, phase 3 trials involving women with fibroid-associated heavy menstrual bleeding. Participants were randomly assigned in a 1:1:1 ratio to receive once-daily placebo, relugolix combination therapy (40 mg of relugolix, 1 mg of estradiol, and 0.5 mg of norethindrone acetate), or delayed relugolix combination therapy (40 mg of relugolix monotherapy, followed by relugolix combination therapy, each for 12 weeks). The primary efficacy end point in each trial was the percentage of participants with a response (volume of menstrual blood loss <80 ml and a ≥50% reduction in volume from baseline) in the relugolix combination therapy group, as compared with the placebo group. Key secondary end points were amenorrhea, volume of menstrual blood loss, distress from bleeding and pelvic discomfort, anemia, pain, fibroid volume, and uterine volume. Safety and bone mineral density were assessed. RESULTS: A total of 388 women in trial L1 and 382 in trial L2 underwent randomization. A total of 73% of the participants in the relugolix combination therapy group in trial L1 and 71% of those in trial L2 had a response (primary end point), as compared with 19% and 15%, respectively, of those in the placebo groups (P<0.001 for both comparisons). Both relugolix combination therapy groups had significant improvements, as compared with the placebo groups, in six of seven key secondary end points, including measures of menstrual blood loss (including amenorrhea), pain, distress from bleeding and pelvic discomfort, anemia, and uterine volume, but not fibroid volume. The incidence of adverse events was similar with relugolix combination therapy and placebo. Bone mineral density was similar with relugolix combination therapy and placebo but decreased with relugolix monotherapy. CONCLUSIONS: Once-daily relugolix combination therapy resulted in a significant reduction in menstrual bleeding, as compared with placebo, and preserved bone mineral density in women with uterine fibroids. (Funded by Myovant Sciences; LIBERTY 1 [L1] and LIBERTY 2 [L2] ClinicalTrials.gov numbers, NCT03049735 and NCT03103087, respectively.).

Modeling-Based Bone Formation in the Human Femoral Neck in Subjects Treated With Denosumab.

Denosumab is associated with continued gains in hip and spine BMD with up to 10 years of treatment in postmenopausal women with osteoporosis. Despite potent inhibition of bone remodeling, findings in nonhuman primates suggest modeling-based bone formation (MBBF) may persist during denosumab treatment. This study assessed whether MBBF in the femoral neck (FN) is preserved in the context of inhibited remodeling in subjects receiving denosumab. This open-label study enrolled postmenopausal women with osteoporosis who had received two or more doses of denosumab (60 mg subcutaneously every 6 months [Q6M]) per standard of care and were planning elective total hip replacement (THR) owing to osteoarthritis of the hip. Transverse sections of the FN were obtained after THR and analyzed histomorphometrically. MBBF, based on fluorochrome labeling and presence of smooth cement lines, was evaluated in cancellous, endocortical, and periosteal envelopes of the FN. Histomorphometric parameters were used to assess MBBF and remodeling-based bone formation (RBBF) in denosumab-treated subjects (n = 4; mean age = 73.5 years; range, 70 to 78 years) and historical female controls (n = 11; mean age = 67.8 years; range, 62 to 80 years) obtained from the placebo group of a prior study and not treated with denosumab. All analyses were descriptive. All subjects in both groups exhibited MBBF in the periosteal envelope; in cancellous and endocortical envelopes, all denosumab-treated subjects and 81.8% of controls showed evidence of MBBF. Compared with controls, denosumab-treated subjects showed 9.4-fold and 2.0-fold higher mean values of MBBF in cancellous and endocortical envelopes, respectively, whereas RBBF mean values were 5.0-fold and 5.3-fold lower. In the periosteal envelope, MBBF and RBBF rates were similar between subjects and controls. These results demonstrate the occurrence of MBBF in the human FN and suggest that denosumab preserves MBBF while inhibiting remodeling, which may contribute to the observed continued gains in BMD over time after remodeling is maximally inhibited. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Further Nonvertebral Fracture Reduction Beyond 3 Years for Up to 10 Years of Denosumab Treatment.

CONTEXT: Evidence for further nonvertebral fracture (NVF) reductions with long-term antiresorptive therapy in osteoporosis is lacking. OBJECTIVE: To evaluate NVF risk reduction in subjects receiving ≤10 years of denosumab treatment. DESIGN: Phase 3, randomized, placebo-controlled, 3-year Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) trial (NCT00089791) and its open-label 7-year extension (NCT00523341). SETTING: One hundred seventy-two study centers worldwide. PATIENTS: Women 60 to 90 years, lumbar spine or total hip bone mineral density T-scores <-2.5 (≥-4.0 at both). INTERVENTIONS: Subjects randomly assigned 1:1 denosumab 60 mg SC Q6M (long-term) or placebo (crossover) in FREEDOM; eligible subjects could enroll in the extension to receive denosumab 60 mg SC Q6M. MAIN OUTCOME MEASURES: NVF Exposure-adjusted subject incidence (per 100 subject-years) during denosumab treatment years 1 to 3 and 4 to 7 (all subjects) and years 4 to 10 (long-term only), and rate ratios (RRs) for years 4 to 7 or 4 to 10 vs 1 to 3. RESULTS: Among 4074 subjects (2343 long-term, 1731 crossover), NVF rates (95% CI) in all subjects were 2.15 (1.90 to 2.43) during years 1 to 3 and 1.53 (1.34 to 1.75) during years 4 to 7 of denosumab treatment [RR (95% CI) = 0.72 (0.61 to 0.86); P < 0.001]; in long-term only were 1.98 (1.67 to 2.34) during years 1 to 3 and 1.44 (1.24 to 1.66) during years 4 to 10 [RR = 0.74 (0.60 to 0.93); P = 0.008]. combined osteonecrosis of the jaw and atypical femoral fracture rate was 0.06. CONCLUSIONS: Long-term denosumab treatment, >3 and ≤10 years, was associated with further reductions in NVF rates compared with the first 3 years.

Invasive Oral Procedures and Events in Postmenopausal Women With Osteoporosis Treated With Denosumab for Up to 10 Years.

CONTEXT: Antiresorptive therapy has been associated with osteonecrosis of the jaw (ONJ), an infrequent but potentially serious adverse event. OBJECTIVE: To assess information on invasive oral procedures and events (OPEs)-dental implants, tooth extraction, natural tooth loss, scaling/root planing, and jaw surgery-during the 7-year Fracture REduction Evaluation of Denosumab in Osteoporosis every 6 Months (FREEDOM) Extension study and to present details of positively adjudicated ONJ cases. DESIGN: Randomized, double-blind, placebo-controlled, 3-year trial (FREEDOM) followed by 7 years of open-label denosumab (FREEDOM Extension). At Extension Year 3, women were asked to record their history of invasive OPEs since the start of the Extension to Year 2.5 and oral events in the prior 6 months. The questionnaire was then administered every 6 months until the end of the Extension. SETTING: Multicenter, multinational clinical trial. PATIENTS: Postmenopausal women with osteoporosis. INTERVENTIONS: Subcutaneous denosumab 60 mg or placebo every 6 months for 3 years, then 7 years of open-label denosumab. MAIN OUTCOME MEASURES: Self-reports of OPEs and adjudicated cases of ONJ. RESULTS: Of respondents, 45.1% reported at least one invasive OPE. The exposure-adjusted ONJ rate in FREEDOM Extension was 5.2 per 10,000 person-years. ONJ incidence was higher in those reporting an OPE (0.68%) than not (0.05%). CONCLUSIONS: Although invasive OPEs were common in these denosumab-treated women and were associated with an increased ONJ incidence, the overall rate of ONJ was low, and all cases with complete follow-up resolved with treatment.

Reduction of Cortical Bone Turnover and Erosion Depth After 2 and 3 Years of Denosumab: Iliac Bone Histomorphometry in the FREEDOM Trial.

Denosumab, a RANKL inhibitor, reduced the risk of vertebral, hip, and nonvertebral fractures in the Fracture REduction Evaluation of Denosumab in Osteoporosis every 6 Months (FREEDOM) trial of postmenopausal women with osteoporosis compared with placebo. Previous bone histomorphometric analysis in FREEDOM showed decreased bone resorption and turnover in cancellous bone after 2 and 3 years. The purpose of the present study was to evaluate the effects of denosumab compared with placebo in the cortical compartment from transiliac bone biopsies obtained during FREEDOM. A total of 112 specimens were evaluable for cortical histomorphometry, including 67 obtained at month 24 (37 placebo, 30 denosumab) and 45 at month 36 (25 placebo, 20 denosumab). Eroded surface, osteoclast surface, erosion depth, and wall thickness were measured on the endocortical surface. Cortical thickness and cortical porosity were also measured. Dynamic parameters of bone formation were assessed for endocortical, periosteal, and intracortical envelopes. Endocortical osteoclast surface, eroded surface, and mean and maximum erosion depth were significantly lower in the denosumab group versus placebo at months 24 and 36 (p < 0.0001 to p = 0.04). Endocortical wall thickness and intracortical measures (cortical porosity and cortical thickness) were not different between the two groups. Dynamic parameters were low with tetracycline labels in cortical bone observed in 13 (43%) and 10 (50%) of denosumab biopsies at months 24 and 36, respectively, reflecting a marked decrease in bone turnover. In conclusion, our data reveal the mechanism of action of denosumab on cortical bone: inhibition of osteoclastic resorption and reduced activation of new remodeling sites. In addition, reduced endocortical erosion depth with no change of wall thickness may contribute to increased bone strength by reducing the bone loss and fragility associated with deep resorption cavities and may likely contribute to the greater BMD gain with denosumab than with other antiresorptive agents. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Denosumab versus risedronate in glucocorticoid-induced osteoporosis: a multicentre, randomised, double-blind, active-controlled, double-dummy, non-inferiority study.

BACKGROUND: Glucocorticoid-induced osteoporosis is the most common form of secondary osteoporosis and is associated with an estimated annual fracture rate of 5%. We aimed to assess the efficacy and safety of denosumab compared with risedronate in glucocorticoid-induced osteoporosis. METHODS: We did a 24-month, double-blind, active-controlled, double-dummy, non-inferiority study at 79 centres in Europe, Latin America, Asia, and North America. Eligible patients were aged 18 years or older and were receiving glucocorticoids (≥7·5 mg prednisone daily, or equivalent) for at least 3 months (glucocorticoid continuing) or less than 3 months (glucocorticoid initiating) before screening. Patients younger than 50 years needed to have a history of osteoporosis-related fracture; glucocorticoid-continuing patients aged 50 years or older needed a lumbar spine, total hip, or femoral neck bone mineral density T score of -2·0 or less, or -1·0 or less if they had a history of osteoporosis-related fracture. Participants were randomly assigned (1:1) to either 60 mg subcutaneous denosumab every 6 months and oral placebo daily for 24 months, or 5 mg oral risedronate daily and subcutaneous placebo every 6 months for 24 months. Randomisation was stratified by sex within each subpopulation, and was done with an interactive voice-response system. Active drugs and corresponding placebos had identical packaging, labels, and appearance. The primary outcome was non-inferiority of denosumab to risedronate in terms of percentage change from baseline in lumbar spine bone mineral density at 12 months based on non-inferiority margins (-0·7 and -1·1 percentage points for the glucocorticoid-continuing and glucocorticoid-initiating subpopulations, respectively). Superiority was also assessed as a secondary outcome. The primary efficacy set included all randomly assigned participants who had a baseline and postbaseline lumbar spine bone mineral density measurement, and was analysed according to randomised treatment assignment. The safety analysis set included all randomly assigned participants who received at least one dose of investigational product, and was analysed by actual treatment received. This study is registered with ClinicalTrials.gov (NCT01575873) and is completed. FINDINGS: Between March 28, 2012, and June 30, 2015, 795 patients, 505 of whom were glucocorticoid continuing and 290 of whom were glucocorticoid initiating, were enrolled and randomly assigned (398 to denosumab, 397 to risedronate). Denosumab was both non-inferior and superior to risedronate at 12 months for effect on bone mineral density at the lumbar spine in both glucocorticoid-continuing (4·4% [95% CI 3·8-5·0] vs 2·3% [1·7-2·9]; p<0·0001) and glucocorticoid-initiating (3·8% [3·1-4·5] vs 0·8% [0·2-1·5]; p<0·0001) subpopulations. Incidence of adverse events, serious adverse events (including infections), and fractures was similar between treatment groups. The most common adverse events were back pain (17 [4%] patients in the risedronate group and 18 [5%] in the denosumab group) and arthralgia (21 [5%] patients in the risedronate group and 17 [4%] in the denosumab group). Serious infection occurred in 15 (4%) patients in the risedronate group and 17 (4%) patients in the denosumab group. INTERPRETATION: Denosumab could be a useful treatment option for patients newly initiating or continuing glucocorticoids who are at risk of fractures. FUNDING: Amgen.

Effects of Long-Term Denosumab on Bone Histomorphometry and Mineralization in Women With Postmenopausal Osteoporosis.

Context: Denosumab is a potent antiresorptive agent that reduces fractures in postmenopausal women with osteoporosis. Objective: Determine effects of up to 10 years of denosumab on bone histology, remodeling, and matrix mineralization characteristics. Design and Setting: International, multicenter, randomized, double-blind trial [Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM)] with a long-term open-label extension. Patients: Postmenopausal women with osteoporosis (92 women in FREEDOM, 46 in extension) who provided iliac bone biopsies, including 11 who provided biopsies at multiple time points. Interventions: FREEDOM subjects were randomized 1:1 to subcutaneous denosumab 60 mg or placebo every 6 months for 3 years. Long-term extension subjects continued receiving denosumab, open-label, for 7 additional years. Outcomes: Bone histology, histomorphometry, matrix mineralization. Results: Ten-year denosumab biopsies showed normal histology. Bone histomorphometry indicated normal bone structure and reduced bone remodeling after 10 years of denosumab, similar to levels after 2 and/or 3 and 5 years of denosumab. The degree of mineralization of bone was increased and mineralization heterogeneity was reduced in the denosumab years 2/3 group vs placebo. Changes in these mineralization variables progressed from years 2/3 to year 5 of denosumab, but not thereafter. Conclusions: Denosumab for 2/3, 5, and 10 years was associated with normal histology, low bone remodeling rate, increased matrix mineralization, and lower mineralization heterogeneity compared with placebo. These variables were unchanged from year 5 to year 10. These data, in combination with the maintenance of low fracture rates for up to 10 years as previously reported with denosumab therapy, suggest that strong, prolonged remodeling inhibition does not impair bone strength.

10 years of denosumab treatment in postmenopausal women with osteoporosis: results from the phase 3 randomised FREEDOM trial and open-label extension.

BACKGROUND: Long-term safety and efficacy of osteoporosis treatment are important because of the chronic nature of the disease. We aimed to assess the long-term safety and efficacy of denosumab, which is widely used for the treatment of postmenopausal women with osteoporosis. METHODS: In the multicentre, randomised, double-blind, placebo-controlled, phase 3 FREEDOM trial, postmenopausal women aged 60-90 years with osteoporosis were enrolled in 214 centres in North America, Europe, Latin America, and Australasia and were randomly assigned (1:1) to receive 60 mg subcutaneous denosumab or placebo every 6 months for 3 years. All participants who completed the FREEDOM trial without discontinuing treatment or missing more than one dose of investigational product were eligible to enrol in the open-label, 7-year extension, in which all participants received denosumab. The data represent up to 10 years of denosumab exposure for women who received 3 years of denosumab in FREEDOM and continued in the extension (long-term group), and up to 7 years for women who received 3 years of placebo and transitioned to denosumab in the extension (crossover group). The primary outcome was safety monitoring, comprising assessments of adverse event incidence and serious adverse event incidence, changes in safety laboratory analytes (ie, serum chemistry and haematology), and participant incidence of denosumab antibody formation. Secondary outcomes included new vertebral, hip, and non-vertebral fractures as well as bone mineral density (BMD) at the lumbar spine, total hip, femoral neck, and one-third radius. Analyses were done according to the randomised FREEDOM treatment assignments. All participants who received at least one dose of investigational product in FREEDOM or the extension were included in the combined safety analyses. All participants who enrolled in the extension with observed data were included in the efficacy analyses. The FREEDOM trial (NCT00089791) and its extension (NCT00523341) are both registered with ClinicalTrials.gov. FINDINGS: Between Aug 3, 2004, and June 1, 2005, 7808 women were enrolled in the FREEDOM study. 5928 (76%) women were eligible for enrolment in the extension, and of these, 4550 (77%) were enrolled (2343 long-term, 2207 crossover) between Aug 7, 2007, and June 20, 2008. 2626 women (1343 long-term; 1283 crossover) completed the extension. The yearly exposure-adjusted participant incidence of adverse events for all individuals receiving denosumab decreased from 165·3 to 95·9 per 100 participant-years over the course of 10 years. Serious adverse event rates were generally stable over time, varying between 11·5 and 14·4 per 100 participant-years. One atypical femoral fracture occurred in each group during the extension. Seven cases of osteonecrosis of the jaw were reported in the long-term group and six cases in the crossover group. The yearly incidence of new vertebral fractures (ranging from 0·90% to 1·86%) and non-vertebral fractures (ranging from 0·84% to 2·55%) remained low during the extension, similar to rates observed in the denosumab group during the first three years of the FREEDOM study, and lower than rates projected for a virtual long-term placebo cohort. In the long-term group, BMD increased from FREEDOM baseline by 21·7% at the lumbar spine, 9·2% at total hip, 9·0% at femoral neck, and 2·7% at the one-third radius. In the crossover group, BMD increased from extension baseline by 16·5% at the lumbar spine, 7·4% at total hip, 7·1% at femoral neck, and 2·3% at one-third radius. INTERPRETATION: Denosumab treatment for up to 10 years was associated with low rates of adverse events, low fracture incidence compared with that observed during the original trial, and continued increases in BMD without plateau. FUNDING: Amgen.

Influence of subject discontinuation on long-term nonvertebral fracture rate in the denosumab FREEDOM Extension study.

BACKGROUND: Denosumab treatment for up to 8 years in the FREEDOM study and Extension was associated with low fracture incidence. It was not clear whether subjects who discontinued during the study conduct had a higher risk of fracture than those who remained enrolled, thereby underestimating the true fracture risk for the entire trial cohort. Thus, we explored the influence of early withdrawals on nonvertebral fracture incidence during the Extension study. METHODS: To understand the potential effect of depletion of susceptible subjects on fracture incidence, we first evaluated subject characteristics in patients who were enrolled in the Extension vs those who were not. We subsequently employed a Kaplan-Meier multiple imputation (KMMI) approach to consider subjects who discontinued as if they remained enrolled with a 0%, 20%, 50%, and 100% increase in fracture risk compared with participants remaining on study. RESULTS: Extension enrollees were generally similar to nonparticipants in median age (71.9 and 73.1 years, respectively), mean total hip bone mineral density T-score (-1.9 and -2.0, respectively), and probability of fracture risk by Fracture Risk Assessment Tool (FRAX®) at FREEDOM baseline (16.9% and 17.7% for major osteoporotic fracture and 6.7% and 7.4% for hip fracture, respectively). When we assumed a doubled fracture risk (100% increase) after discontinuation in KMMI analyses, nonvertebral fracture rate estimates were only marginally higher than the observed rates for both the crossover group (10.32% vs 9.16%, respectively) and the long-term group (7.63% vs 6.63%, respectively). CONCLUSION: The observation of continued denosumab efficacy over 8 years of treatment was robust and does not seem to be explained by depletion of susceptible subjects. TRIAL REGISTRATION: ClincalTrials.gov registration number NCT00523341 ; registered August 30, 2007.