Clinical Trial Details
— Status: Not yet recruiting
Administrative data
NCT number |
NCT04688983 |
Other study ID # |
SPON-1751-19 |
Secondary ID |
|
Status |
Not yet recruiting |
Phase |
Phase 2
|
First received |
|
Last updated |
|
Start date |
January 2021 |
Est. completion date |
January 2026 |
Study information
Verified date |
December 2020 |
Source |
Cardiff University |
Contact |
Oliver Ottmann |
Phone |
02920742375 |
Email |
ottmanno[@]cardiff.ac.uk |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
An Open Label, 3-arm, Randomised Phase II Study to Compare the Safety and Efficacy of
Ponatinib in Combination With Either Chemotherapy or Blinatumomab With Imatinib Plus
Chemotherapy as Front-line Therapy for Patients Aged 55 Years and Over With Philadelphia
Chromosome Positive (Ph+ or BCR-ABL+) Acute Lymphoblastic Leukemia (ALL)
Description:
Acute lymphoblastic leukemia (ALL) develops when a certain type of immature bone marrow cell
called a lymphoblast becomes malignant, resulting in uncontrolled growth and suppression of
normal blood cell development. Leukemic blast cells accumulate in the bone marrow and blood
and may involve other organs such as the central nervous system (CNS). The most frequent
subtype of ALL observed in adults is caused by a genetic aberration called a Philadelphia
(Ph) chromosome and is thus referred to as Ph+ ALL. In this type of ALL, a gene called BCR
and a gene called ABL are fused by a process known as translocation. This leads to formation
of an atypical gene called BCR-ABL and formation of a protein known as the BCR-ABL
oncoprotein. This protein, a so-called tyrosine kinase, activates and disrupts many signaling
pathways in the cell and is directly responsible for the development of Ph+ ALL, which is one
of the most aggressive types of leukaemia.
Treatment options for Ph+ ALL were much improved by a family of drugs called tyrosine kinase
inhibitors (TKI), which bind to - and block the activity of - the BCR-ABL kinase. The first
of these drugs to be developed is called imatinib (brand name glivec), which has become a
standard component of therapy for Ph+ ALL worldwide, usually combined with steroids and/or
cytotoxic chemotherapy typically used for ALL. In the vast majority of patients, this
treatment is initially able to reduce the burden of the disease to a very low level (complete
remission). Unfortunately, the leukemic cells eventually become resistant to imatinib,
causing the disease to reappear (relapse). A commonly observed mechanism of resistance to TKI
is the development of mutations in the BCR-ABL gene, as a result of which the drug can no
longer bind to the kinase, leading to its reactivation. For this reason, stem cell
transplantation from a sibling or unrelated donor is considered the most effective treatment
to achieve cure.
In the last couple of years, 2nd generation TKI (Dasatinib and Nilotinib) which are more
active than imatinib have been tested in clinical trials in patients with Ph+ ALL. Although
these newer TKI show activity towards mutated BCR-ABL not inhibited by imatinib, the same
basic mechanisms of resistance apply to these drugs, and they have not been shown to result
in substantially longer survival than imatinib. In particular, a BCR-ABL mutation known as
T315I has been recognized to cause resistance to all approved 1st and 2nd generation TKI.
More recently, a highly potent 3rd generation TKI called ponatinib has been developed and is
the only approved TKI shown to be active against the T315I and all other resistance
mutations. Initial studies combining ponatinib with chemotherapy have shown excellent
response rates and promising survival in adult patients with newly diagnosed Ph+ ALL.
However, in this group of patients ponatinib has not yet been directly compared with any of
the other drugs, and there may be a moderately increased risk of vascular and cardiac adverse
events, such as heart attacks, strokes or thrombosis.
Based on existing data, ponatinib shows great promise for treatment of Ph+ ALL, but its
superiority over standard imatinib-based therapy in terms of long-term efficacy and safety
need to be proven.
It is the main purpose of this trial to determine whether ponatinib is superior to imatinib
when combined with the same chemotherapy that is considered a standard for elderly patients
with Ph+ ALL. The study hypothesis is that a greater proportion of patients in the ponatinib
arm will achieve a deep (molecular) response, and that survival without leukemia relapse will
be superior. The side effects, safety and tolerability of the two treatment regimens will
also be compared.
A second trial question will explore whether chemotherapy can be omitted from the treatment
regimen by replacing it with an immunotherapy drug called blinatumomab. This is a type of
antibody that activated the patient´s own immune cells (T-cells) and directs them to the
leukaemia cells, which are then destroyed. This type of treatment has been very effective in
patients with ALL that did not respond or returned after other types of therapy, and has been
approved in the EU and USA as salvage therapy for ALL. By combining two very different types
of targeted therapy, the TKI ponatinib and the antibody blinatumomab, we hope to deliver
highly effective therapy for Ph+ ALL while eliminating the toxicity of chemotherapy.
To be able to compare these treatments, patients will be randomly assigned to the three
treatment arms in a 1:1:1 ratio, i.e. the likelihood to be assigned to each of the treatment
groups is the same. Overall duration of study treatment will be 2 years, followed by
treatment with the TKI alone.