The following is an excerpt from Eric Ende of lehman's recent report on IDPH. He is an IDEC bull and has a hold on CLTR. I think his argument that efficacy and safety data are not the critical elements but rather convenience is rather weak. I also think that Zev.s higher toxicity and lack of dosemitry will trouble the FDA especially if CLTR gets there first, which is a big if. The median age difference in the studies of 56 and 49 is not significant. Others have thoughts.
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Although the data suggests greater toxicity and lower efficacy than Bexxar, a
potentially competing drug from Coulter Pharmaceuticals (CLTR - $15 11/16, 3-
Neutral), we would like to caution investors not to compare the drugs across
independent studies as different traits of the patient populations within the
studies may bias the results. Moreover, characteristics of the drugs will
likely influence the drugs' eventual utilization once they reach the market.
We believe that cost and convenience will ultimately determine market
acceptance.
STUDY #1: ZEVALIN IN RITUXAN-REFRACTORY PATIENTS
CONCLUSION: The overall response rate (ORR) was lower than would be expected;
however, it is not surprising since the patients had previously failed
Rituxan, which kills tumor cells via a similar mechanism to Zevalin. Because
the patients had failed Rituxan previously, we can assume that the patients
were less likely to respond to this mechanism, therefore we conclude that the
ORR would be lower. Although toxicity is higher than one would hope, Zevalin
is a drug that will be used in refractory patients, thus the hurdle is much
lower. In addition, oncologists are prepared for blood toxicity given that
standard chemotherapy regimens are significantly more toxic than Zevalin
DATA: The first study is an open-label non-randomized phase III trial that
tests Zevalin in Rituxan-refractory patients that have received 3 prior
therapies. There were 26 patients in the interim analysis. The median age
of the patients was 56 years. The ORR was 46%. Most toxicity was blood-
related as the median nadirs (low points) for white blood cells and platelets
was 900 and 34,000, respectively. Transient grade 4 thrombocytopenia (low
platelets) and neutropenia (low white blood cells) was present in 8% and 23%
of patients, respectively. Recovery occurred within 2 weeks.
STUDY #2: ZEVALIN VERSUS RITUXAN
CONCLUSION: The overall response rate (ORR) was as expected for both the
Zevalin and the Rituxan groups. Notice that since these patients were NOT
Rituxan-refractory as in the previous study, the ORR for the Zevalin group
was much higher at 80%. This suggests that the similar mechanism for each of
the drugs likely affected the ORR for Zevalin in the Rituxan-refractory
study.
DATA: The second study is a prospective randomized controlled trial comparing
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