A Phase 1/2 Open-label Study to Assess the Safety, Tolerability and Preliminary Efficacy of TH-302, A Hypoxia-Activated Prodrug, and Dexamethasone With or Without Bortezomib in Subjects With Relapsed/Refractory Multiple Myeloma
This is the initial study of TH-302 in subjects with relapsed/refractory multiple myeloma.
It is an open-label dose-escalation study to determine the DLTs, MTD, safety and preliminary
efficacy of TH-302 as a monotherapy with a Simon two-stage expansion at the MTD. The study
will also investigate the DLTs, MTD, safety and preliminary efficacy of TH-302 in
combination with Bortezomib. As such, the study is separated into three parts. Treatment
will be administered on a 21-day cycle, until disease progression or unacceptable toxicity,
or 12 cycles have been completed.
Part A: Monotherapy TH-302 Dose Escalation
The dose of TH-302 will be escalated in cohorts of 3-6 subjects. The initial dose of TH-302
will be 240 mg/m2. A Dose Level minus 1 will be built into the study in the event that
subjects experience excessive toxicity at Dose Level 1. Dose escalation will continue with
approximately 40% increases from the previous dose level; however lower dose increases of
20-39% may be implemented after consultation between the Investigators, Medical Monitor and
Sponsor with the percent increase dependent on the current dose level and the cumulative
safety data.
Before applying the dose escalation rules, all three subjects in a given cohort dose level
must complete 21 days (1 cycle) of therapy and safety evaluation. If the first 3 subjects
within a cohort tolerate the first 21 days of therapy without dose limiting toxicity (DLT)
as defined below, the next cohort may proceed.
If one of 3 subjects experiences a DLT during the first treatment cycle, 3 additional
subjects will be enrolled at that dose level for a total of 6 subjects in that cohort. If
no additional DLTs are observed, the next dose escalation will resume. However, if 2 or
more of 6 subjects within a cohort experience a DLT, that dose will be considered to exceed
the MTD. If at any time during a cohort, >2 subjects experience a drug-related DLT, the MTD
will have been exceeded, additional enrollment will cease and dose escalation will stop.
The MTD will then be defined at the highest dose level whereby 6 subjects were treated and
no more than 1 subject experienced a DLT and at least 2 subjects had a DLT at the next
higher dose level. The maximum safe dose of TH-302 will be the single agent MTD or the
highest dose tested in that study if the MTD was not reached.
Once the MTD has been reached an additional 3 subjects (for a total of 9) will be dosed at
the MTD to access efficacy. If 2 DLTs do not occur in any dose level of the dose escalation
of Part A and the highest dose tested is defined as the MTD, an additional 3 subjects (for a
total of 9) will be dosed at the highest dose tested.
A Simon two-stage design will be implemented at the MTD. If there is sufficient activity (1
or more subjects of the first 9 subjects achieves partial response or better), then
monotherapy enrollment will be expanded to Part B. If there is insufficient activity (no
partial response or better in 9 subjects), then no further investigation of TH-302 as a
monotherapy is warranted and investigation of TH-302 in combination with bortezomib begins
in Part C.
Part B: Monotherapy TH-302 MTD Dose Expansion
If there is sufficient activity in Part A at the MTD (at least 1 of 9 subjects achieves
partial response or better), an additional 15 subjects will be enrolled for a total of 24
subjects treated at the MTD. After the last patient in the Part B expansion has completed
Cycle 1 and review of the cumulative safety data confirms that the monotherapy is
well-tolerated, patients may be enrolled into Part C of the trial (TH-302 in combination
with bortezomib).
Part C: TH-302 Dose Escalation in combination with bortezomib
The dose of TH-302 will be escalated in cohorts of 3-6 subjects. The initial dose of TH-302
will be 240 mg/m2. Follow same DLTs as above. A Dose Level minus 1 will be built into the
study in the event that subjects experience excessive toxicity at Dose Level 1. Dose
escalation will continue with 40% increases from the previous dose level; however lower dose
increases of 20-39% may be implemented after consultation between the Investigators, Medical
Monitor and Sponsor with the percent increase dependent on the current dose level and the
cumulative safety data.
The dose of bortezomib will remain fixed at 1.3 mg/m2. If a subject experiences a DLT, 3
additional subjects will be enrolled at that dose level for a total of 6 subjects in that
cohort. If no additional DLTs are observed, dose escalation will resume. However, if 2 or
more of 6 subjects within a cohort experience a DLT, that dose will be considered to exceed
the MTD. The MTD will then be defined at the next lower dose level whereby 6 subjects were
treated and no more than one subject experienced a DLT. The maximum safe dose of TH-302 and
1.3 mg/m2 of bortezomib will be the combination MTD or the highest dose tested if the MTD
was not reached.
The MTD will be based on toxicities occurring during the first cycle.
An additional 6 subjects (for a total of 12) will be enrolled at the MTD for the dose
expansion portion of the study. If 2 DLTs do not occur in the dose escalation of Part C and
the highest dose tested is defined as the MTD, an additional 6 subjects (for a total of 12)
will be dosed at the highest dose tested.
TH-302 will be administered by IV infusion over 30-60 minutes on Days 1, 4, 8 and 11 of a 21
day cycle.
Bortezomib will be administered by IV push over 3-5 seconds on Days 1, 4, 8 and 11 of a 21
day cycle. On days where bortezomib and TH-302 are given on the same day, administer
bortezomib at least 2 hours after TH-302 infusion.
There will be no dose escalation in individual subjects. Missed doses will not be made up.
Doses of TH 302 or bortezomib may be rescheduled for +2 days, if the scheduled dose falls on
a holiday. Anticipated delays of >2 days should be discussed with the medical monitor.
Subjects who successfully complete a 3-week treatment cycle without evidence of significant
treatment-related toxicity or progressive disease will continue to receive treatment for up
to 12 cycles.
Up to six subjects may be enrolled in any of the other cohorts below the MTD. Subjects
receiving less than 4 days of dosing and not experiencing a DLT during Cycle 1 will be
replaced. In addition, subjects not completing the first 21 days of Cycle 1 and not
experiencing a DLT may be replaced at the discretion of the Principal Investigator.
Interventional
Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment
safety and tolerability of TH-302 monotherapy and in combination with bortezomib in subjects with relapsed/refractory multiple myeloma
2 years
Yes
United States: Food and Drug Administration
TH-CR-408
NCT01522872
February 2012
January 2014
Name | Location |
---|---|
Dana-Farber Cancer Institute | Boston, Massachusetts 02115 |
Massachusetts General Hospital | Boston, Massachusetts 02114-2617 |
Moffitt Cancer Center | Tampa, Florida 33612 |
Colorado Blood Cancer Institute | Denver, Colorado 80218 |