Item 8.01 Other Events.
Corporate Update
On August 13, 2019, Deciphera Pharmaceuticals, Inc. (the Company or we) announced positive
top-line
data from its INVICTUS pivotal Phase 3 clinical study of ripretinib, a broad-spectrum KIT and PDGFRα inhibitor, in patients with fourth-line and fourth-line plus gastrointestinal stromal tumor, or
GIST. The Company also announced positive updated data from its ongoing Phase 1 clinical study of ripretinib.
Top-line
Results from INVICTUS Phase 3 Study in Fourth-Line and Fourth-Line Plus GIST
The INVICTUS
Phase 3 clinical study is a randomized, double-blind, placebo-controlled, international, multicenter study to evaluate the safety, tolerability, and efficacy of ripretinib compared to placebo in patients with advanced GIST whose previous therapies
have included imatinib, sunitinib, and regorafenib.
On August 13, 2019, we announced
top-line
data from the INVICTUS Phase 3 clinical study, including that the trial achieved its primary endpoint of improved progression free survival, or PFS, compared to placebo in patients with fourth-line
and fourth-line plus GIST, as determined by blinded independent central radiologic review using modified Response Evaluation Criteria in Solid Tumors, or RECIST, version 1.1.
In the INVICTUS study, ripretinib demonstrated a median PFS of 6.3 months (27.6 weeks) compared to 1.0 month (4.1 weeks) in the placebo arm
and significantly reduced the risk of disease progression or death by 85% (HR of 0.15, p<0.0001) compared to placebo.
For the key
secondary endpoint of objective response rate, or ORR, as determined by blinded independent central radiologic review using modified RECIST version 1.1, ripretinib demonstrated an ORR of 9.4% compared with 0% for placebo
(p-value=0.0504),
which was not statistically significant. Ripretinib in this study also showed a clinically meaningful improvement over placebo in terms of the secondary endpoint of overall survival, or OS (median
OS 15.1 months with ripretinib compared to 6.6 months with placebo, HR = 0.36, nominal
p-value=0.0004).
Since statistical significance was not achieved for ORR, the hypothesis testing of OS was not formally
performed. According to the
pre-specified
hierarchical testing procedure of the endpoints, the hypothesis testing of OS cannot be formally conducted unless the test of ORR is statistically significant. The OS
data for the placebo arm includes patients taking placebo who, following progression, were crossed-over to ripretinib treatment.
Ripretinib was generally well tolerated and the adverse event results in INVICTUS were consistent with data from previously presented Phase 1
study results. Grade 3 or 4 treatment-emergent adverse events, or TEAEs, occurred in 42 patients (49%) on the ripretinib arm compared to 19 patients (44%) on the placebo arm. Grade 3 or 4 TEAEs in greater than 5% of patients in the ripretinib arm
were anemia (9%; n=8), abdominal pain (7%; n=6) and hypertension (7%; n=6). Grade 3 or 4 TEAEs in greater than 5% of patients in the placebo arm were anemia (14%; n=6). The below table lists all TEAEs greater than 15% in the ripretinib arm compared
to the placebo arm in INVICTUS.
|
|
|
|
|
INVICTUS Phase 3 Clinical
Study
|
Treatment Emergent Adverse Event
|
|
Placebo
(N=43)
(1)
|
|
Ripretinib
150mg Daily
(N=85)
(1)
|
Any event
|
|
42 (98%)
|
|
84 (99%)
|
Alopecia
|
|
2 (5%)
|
|
44 (52%)
|
Fatigue
|
|
10 (23%)
|
|
36 (42%)
|
Nausea
|
|
5 (12%)
|
|
33 (39%)
|
Abdominal pain
|
|
13 (30%)
|
|
31 (36%)
|
Constipation
|
|
8 (19%)
|
|
29 (34%)
|
Myalgia
|
|
5 (12%)
|
|
27 (32%)
|
Diarrhea
|
|
6 (14%)
|
|
24 (28%)
|
Decreased appetite
|
|
9 (21%)
|
|
23 (27%)
|
Palmar-plantar erythrodysaesthesia syndrome
|
|
0
|
|
18 (21%)
|
Vomiting
|
|
3 (7%)
|
|
18 (21%)
|
Headache
|
|
2 (5%)
|
|
16 (19%)
|
Weight decreased
|
|
5 (12%)
|
|
16 (19%)
|
Arthralgia
|
|
2 (5%)
|
|
15 (18%)
|
Blood bilirubin increased
|
|
0
|
|
14 (16%)
|
Oedema peripheral
|
|
3 (7%)
|
|
14 (16%)
|
Muscle spasms
|
|
2 (5%)
|
|
13 (15%)
|
(1) Safety population includes 128 patients. One patient was randomized to placebo but did not receive study
drug.
2