GS: ABGX (IL/N): ASCO update, incremental P2
pantitumumab data, BLA on track potential
H205
52-Week Range US$16-7
YTD Price Change -27.66%
Market Cap US$664.5mn
EPS Growth Estimate NA
Fiscal Year (ending in Dec)
2004 2005E 2006E
US$-1.92 US$-2.05 US$-2.00
An update on previously reported data from an ongoing Phase II colorectal study with
panitumumab as monotherapy in refractory patients was reported at ASCO this morning.
Consistent with previously reported data, an overall response rate of 9%, and median time
to progression of 11.4 weeks was reported. We believe that panitumumab is on track for
potential BLA submission in H2 2005, assuming positive data. Abgenix and Amgen
(OP/N) are developing panitumumab through a 50/50 partnership. A front line study with
Avastin is underway, which we believe will be important for positioning longer term. In
H2 2005 we look for phase II data in the lung, renal and colorectal cancer settings. We
regard progress with panitumumab is the primary valuation driver. We maintain an
In-Line rating on Abgenix and Neutral coverage view. Key risks include potential clinical
failures and/or delays.
I. Investment Outlook
We maintain an In-Line rating on Abgenix and a Neutral coverage view. We believe that
Abgenix is best suited for risk tolerant investors with a long time horizon. The successful
submission of a panitumumab (ABX-EGF) BLA filing in the second half of 2005 would represent
an important milestone for Abgenix as would potential data indicative of panitumumab's potential in
other cancer settings and as part of earlier and combination treatment regimens. Abgenix is
developing panitumumab through a 50/50 profit share agreement with Amgen. Amgen controls
clinical studies. Behind panitumumab, the proprietary pipeline is relatively early stage, with the
most advanced candidate being ABX-PTH, in Phase I for secondary hyperparathyroidism. With
partners, 11 antibodies are now in clinical testing.
Partnered antibodies that are gaining visibility
include Amgen's AMG-162 for osteoporosis, in Phase III studies, and Pfizer's CTLA4 antibody for
cancer, in Phase I. We note that in addition to these, Amgen has an additional antibody in the clinic,
Pfizer has 3, Curagen, Chiron and Human Genome Sciences each have an antibody in the clinic.
II. Update on Phase II monotherapy colorectal study
This morning updated results from an ongoing Phase II monotherapy study in 148 refractory
colorectal cancer patients were reported. Treatment with panitumumab resulted in a 9% overall
response rate and a median time to progression of 11.4 weeks.
Patients expressing the EGFr protein
demonstrated a median survival time of 37.6 weeks and 18.1 week median duration of tumor
response. The median progression free survival time was 13.6 weeks and disease stabilization was
reported in 29% (43) patients. These data are consistent with previously reported data. At ASCO in
June 2004, a 10% response rate was reported, consistent with data from the first 44 patients,
presented at ASCO 2003. The median time to progression was 2 months and median overall
survival was 7.9 months. Consistent with previously reported data, the most common side effect
was skin rash (95%). Other side effects included fatigue, nausea and mild diarrhea. No human
antihuman antibodies were detected in patients tested (n=107).
III. Dose finding study supports, weekly, every 2 and 3 week dosing
In addition, results from a Phase 1 study suggest similar exposure profiles with weekly, every other
week and every 3 week dosing intervals. At ASCO 2005, data were presented from a Phase 1 open
label study in 96 patients, which suggest similar exposure and tolerability when panitumumab is
administered by weekly, every other week, and every third week dosing schedules. Patients received
four infusions of panitumumab, at doses of between 0.01 to 5.0 mg/kg once per week, 6.0 mg/kg
every two weeks or 9.0 mg/kg once every three weeks. The 6.0 mg/kg regimen is being assessed in
pivotal studies.
IV. Pivotal studies underway, potential BLA H2 2005
Enrollment of the ex U.S. study is complete and will likely be used as the basis for filing, assuming
data are positive. The primary end point is progression free survival. We look for potential
submission in H2 2005. Depending on event rates, it is possible that filing could occur later,
although that would suggest a better result. Data from the U.S. study, which has been slow to enroll
due to competitive products, will likely be filed in support of the international study. Abgenix and
Amgen have indicated that based on regulatory feedback, that submission of data from either of the
two ongoing pivotal studies, plus supportive data, would be acceptable for filing. Patients in the
pivotal studies have 3rd line colon cancer and will have been exposed to 5-FU, leucovorin,
oxaliplatin and/or irinotecan.
V. First line colorectal study with Avastin, (PACCE Study) underway
Abgenix and Amgen announced in April, that the PACCE (Panitumumab Advanced Colorectal
Cancer Evaluation) study, a Phase III trial to involve roughly 1,000 patients, in first line colorectal
cancer was initiated. The study is a randomized, open label study with the endpoints of progression
free survival, overall survival and response rate. Patients will receive panitumumab plus Avastin,
with either oxaliplatin (Eloxatin) or irinotecan (Campostar) based therapy. Results from this study
may be important for longer term positioning of panitumumab, (an EGF inhibitor) as part of
combination therapy with VEGF inhibitors, which Avastin is.
In addition to Avastin, panitumumab
is also being studied with an Amgen VEGF inhibitor, AMG706. As we expect panitumumab may be
the fourth potential EGF inhibitor on the market (although only the second antibody), and given the
strong efficacy established with Avastin in this setting, combination studies will be a central part of
the strategy to expand the market.
VI. Other potential panitumumab data H2
Non-small cell lung cancer - first line, data expected in H2 2005
Approximately 175 patients have been enrolled in this study which compares panitumumab plus
chemotherapy to chemotherapy alone (paclitaxel and carboplatin) in first-line non-small cell lung
cancer. Data from this study is expected in the second half of 2005. The study will assess time to
tumor progression (primary endpoint), response rate, and survival. Interim data from this study were
reported at ASCO 2004. Nineteen patients were evaluated of which there was one complete
response and four partial responses. We regard this data as encouraging but early.
Renal cancer
Positive initial Phase II data on panitumumab as monotherapy in 88 advanced kidney cancer
patients were reported at ASCO in May, 2002. At 8 weeks, stable disease was achieved in 50% of
the patients. We believe this is a strong start given the severity of the patients studied, and the fact
that ABX-EGF was studied as monotherapy. The second part of this study will assess less heavily
pretreated patients and has enrolled 115 patients. The dose is 2.5 mg/kg weekly over an 8 week
cycle. We may see updated results from this study in 2005.
VII. Competitive landscape
Panitumumab (ABX-EGF) is a fully human antibody to the EGF receptor, which is over-expressed
in a range of cancers. Data from AstraZeneca's Iressa, ImClone/Bristol Myers' Erbitux, and
Genetech/OSIP's Tarceva have fueled interest in and validated the EGF mechanism. The 2004
approval of Genentech's Avastin, a VEGF inhibitor, with a mortality benefit in the colorectal and
now lung setting is a significant advance. While the market for newer biologics has gotten more
competitive, we believe that there is room for more than one player. We believe that panitumumab
could potentially have dosing, side effect and possibly pricing advantages with respect to the other
EGF antibody, Erbitux. Moreover, we believe there is greater commercial opportunity for
panitumumab and the class, with label expansion and in combination therapy with different
chemotherapy and other growth factor inhibitors. Early clinical studies are under way with
panitumumab in combination with Amgen's AMG706, an oral multi-kinase inhibitor which inhibits
VEGF, PDGF receptor and other targets. As with clinical data released from the BOND studies with
Avastin and Erbitux, it is thought that the combination EGF and VEGF inhibitors may provide
added benefit.
I, Meg Malloy, hereby certify that all of the views expressed in this report accurately reflect my
personal views about the subject company or companies and its or their securities. I also certify that |
