Event - Celldex hoping Asco data will move cancer vaccine into phase III


The recent approval of Dendreon’s Provenge means cancer vaccines will be attracting much attention at this year’s Asco, the annual US cancer conference that starts in early June. One product in the spotlight will be CDX-110, developed by Celldex Therapeutics and licensed by Pfizer, which is due to present phase II data in brain cancer.

Expectations are mounting that Pfizer is preparing to move CDX-110 into pivotal trials, which will signal a big vote of confidence in the product. Celldex shares have climbed 73% this year to $8.08, most notably in the last few months, suggesting that investors at least are already betting on a positive read out at Asco and phase III initiation.

Product CDX-110
Company Celldex Therapeutics
Market Cap $257m
Product NPV $1,318m
% of Market Cap 513%
Event type Phase II data
Date June 2010
Could Impact Oncophage (Antigenics)

CDX-110 targets the tumour specific epidermal growth factor receptor variant III (EGFRvIII). EGFRvIII is only expressed in cancer cells and is a transforming oncogene that can directly contribute to cancer cell growth. It is present in 25-40% of glioblastoma multiforme tumours, according to Celldex.

Data presented at last year’s Asco, from patients taking part in previous phase II studies, pointed towards an improvement in time to tumour recurrence and overall survival. The Activate study, which included 22 patients, improved survival to 22 months and Act II, in 23 patients, improved survival to 26 months, which compares favourably with the 15.2 months normally expected for these patients.

The most recent study, Act III, again evaluates CDX-110 when given with standard of care, radiation and temozolomide, in patients with malignant glioma. It is the biggest trial so far, in 60 patients. Treatment was given until disease progression and patients followed for long term survival data. Efficacy was measured by the progression free survival status at 5.5 months from the date of the first dose. It is unlikely that complete survival data will be available at Asco.

Slowly does it

Pfizer bought rights to CDX-110 in April 2008, paying $40m upfront and making a $10m equity investment in Avant Immunotherapeutics, Celldex’s predecessor.

At the time the product was already in a phase II/III study, but when Pfizer came on board development was slowed down considerably, and the study was amended to become the current, single arm phase II Act III study.
Although on the surface this meant the project was significantly prolonged, if anything has been learnt by the numerous phase III failures the cancer vaccine field has seen it is that rigorous earlier stage testing, to closely define a targeted patient population, is vital.

Making it personal

In February, Pfizer signed a deal with Qiagen to develop a companion diagnostic test for CDX-110, to identify patients with the EGFRvIII mutation. So should phase III trials be started Pfizer now knows exactly the patients it is going for and has a companion diagnostic to use in the pivotal trial, which can only improve the chances of success.

Analysts covering Pfizer have pencilled in launch in 2012, which looks ambitious, and sales of $84m by 2016, according to consensus data from EvaluatePharma. Analysts at Needham who follow Celldex reckon the product could generate peak sales of $300-$500m a year.

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