By 2030 over 25% of the entire US population will be older than 65 years of age. Pelvic
fracture rates are higher in women. Over 90% of pelvic fractures in patients >60 years
are defined as osteoporosis related fractures. In a recent study in Germany, the rate of
all first pelvic fractures in persons over 60 was 22.4 [95% CI 22.0-22.9] per 10,000
person-years. The incidence rate increases dramatically with age, from 5.4 and 3.8 per
10,000 person-years in women and men aged 65 to 69 years to 93.5 and 44.5 per 10,000
person-years in women and men aged 90 years and older, respectively. This is in agreement
with studies in the US and Finland, also showing an increase in incidence of pelvic
fractures with age. Pelvic fractures are most often a result of low-energy trauma, such
as a fall from standing height. Pelvic fractures are the most relevant for this proposed
randomized placebo-controlled study. This fracture is accompanied by severe pain, chronic
immobility and loss of function and independence in the elderly. The current treatment
strategy of pelvic fractures includes pain management, patient mobilization, and the
prevention of complications associated with comorbid conditions. In a review of six
studies with over 500 patients, the mean length of hospital stay was 13.4 days and the
average 1-year mortality was 16.3%. Mortality rates in 1300 pelvic fracture patients were
still elevated at 3 years. Pelvic fractures are associated with slow healing and a
delayed return to full function and normal activity. Pelvic fractures consume substantial
healthcare resources, and based on administrative claims data, they are one of the most
costly osteoporosis related fractures. Un-healed fractures, occurring in one-third of
pelvic fracture patients at 3 months, can cause continued pain and impact mobility. With
aging of the population and expected concomitant increase in the incidence of pelvic
fractures, there is a pressing need to find effective treatments that will accelerate
healing. There are strong preclinical data, as well as clinical evidence, that
administration of parathyroid hormone (PTH) receptor agonists may improve bone union,
hasten fracture healing and improve physical function. In one nonrandomized, un-blinded
study, 100% of pelvic fracture patients given 1-84PTH were healed within 12 weeks
compared to 68% of the controls. However, there is not sufficient evidence at this time
to recommend routine use of PTH receptor agonists for fracture healing. Pelvic fractures
are ideal to study for the impact of abaloparatide on rate of fracture healing because
there are no surgical repairs for the vast majority of the fractures. Prior studies of
teriparatide on wrist fracture healing were limited and confounded by the increased
prevalence of surgical fixation to treat these fractures. Strong evidence of pelvic
fracture healing that may result from this study may not only have an impact on pelvic
fractures but perhaps may indicate a potential use for other fractures as well.
In the proposed randomized, double blind, placebo controlled clinical trial in patients
>50 years of age with acute pelvic fracture, the investigators plan to evaluate whether
treatment with daily subcutaneous ABALOPARATIDE 80 mcg/day compared with placebo, in
addition to standard treatment (pain management, bed rest and prevention of complications
from comorbid conditions), is effective in accelerating fracture healing in women and men
compared to standard treatment alone. The investigators hypothesize that development of a
successful adjunctive therapy (ABALOPARATIDE) will accelerate radiographic evidence of
fracture healing and speed functional recovery. If this hypothesis holds true, it would
lead to a change in clinical practice and an improved quality of care for pelvic fracture
patients. Evidence of an impact on the healing of pelvic fractures may also extend to a
potential to improve healing of other osteoporosis-related fractures. In the planned
trial the investigators will recruit women and men with acute pelvic fractures and
address 3 specific aims over 3 months of treatment in a placebo controlled double blind
study to determine if ABALOPARATIDE in addition to standard care versus placebo and
standard care:
Results in evidence of more complete cortical bridging at 3 months using focus CT to
reduce radiation exposure from CT scans (primary outcome).
Leads to a faster reduction in pain as assessed by both the Numeric Rating Scale and
a reduction in the use of narcotics (secondary outcome).
Leads more to a more rapidly improved functional outcome using measures to assess
lower extremity function (Continuous Summary Physical Performance Score and Timed Up
and Go- secondary outcomes).
Although the primary analysis will be based on data from 0 to 3 months, whether the
benefit of ABALOPARATIDE on fracture healing wanes over time is unclear, making a longer
follow-up important to extend knowledge on the persistence of early ABALOPARATIDE effect
on these outcomes. Therefore, the investigators will extend this study with 9 months of
open label ABALOPARATIDE to determine if any potential differences between the placebo
and ABALOPARATIDE groups during the 3 months of treatment are evident and persist over
time, even in patients who use ABALOPARATIDE after the three month placebo controlled
intervention.
If ABALOPARATIDE can improve fracture healing, this study will have an impact on the
treatment of persons with pelvic fracture who are not surgical candidates and often face
severe pain, chronic immobility, and loss of function in the elderly. A positive finding
of accelerated healing of pelvic fractures would also encourage study of ABALOPARATIDE
for treatment of other osteoporotic fractures.