Radioimmunotherapy, or RIT for short, is a combination of two treatments namely, radiotherapy and monoclonal antibodies. This targeted cancer therapy involves the use of antibodies labeled with radioisotopes to deliver therapeutic dose of radiation directly to the tumor cells.
Spectrum Pharmaceuticals Inc.'s (SPPI) Zevalin and Bexxar co-developed by Corixa Corp. (CRXA) and GlaxoSmithKline (GSK), for treating certain types of non Hodgkins lymphoma are examples of FDA-approved radioimmunotherapy treatments.
Zevalin became the first radioimmunotherapy treatment to be approved when the FDA in 2002 gave green signal to the drug for the treatment of adults with relapsed or refractory low-grade, follicular B-cell lymphoma. In September 2009, the FDA approved expanded use of Zevalin as a first-line treatment for follicular B-cell non-Hodgkin's lymphoma. The drug is currently approved in more than 40 countries.
The treatment with Zevalin has so far been complex. Typically, the first step in Zevalin therapeutic regimen is intravenous infusion of Rituximab followed by an injection of Indium-111 radiolabeled Zevalin. Then, using a gamma camera, the whole body images of the patients will be taken within ten minutes and again on Day 3 or 4 of injection of Indium-111. The purpose of the bioscan is to pre-determine the distribution of Zevalin throughout the body prior to the administration of the therapeutic dose of Zevalin, and has no therapeutic effect on the patients. If the biodistribution is acceptable, a second intravenous infusion of Rituximab is given on treatment day 7, 8 or 9, followed by a therapeutic dose of Yttrium-90 Zevalin.
Seeking to remove the pre-treatment imaging evaluation, more commonly referred to as the "bioscan" requirement for Zevalin, Spectrum Pharma submitted relevant data to the FDA earlier this year.
Today - November 21, Spectrum Pharma announced that the removal of the bioscan requirement for Zevalin was approved by the FDA after the market close on November 18, 2011, and is effective immediately.
With the bioscan requirement removed, patients undergoing treatment with Zevalin will receive the two infusions of Rituximab followed by a 10-minute injection of Zevalin. This simplified regimen will now be called "RRZ" - Rituximab, Rituximab, Zevalin.
According to Spectrum Pharma, patients undergoing treatment with Zevalin no longer need to be exposed to unnecessary radiation with Indium-111 or be burdened by the inconvenience of the bioscan requirement.
Last year, Zevalin recorded sales of $29 million, up from $16 million in 2009. In the nine months ended September 30, 2011, Zevalin sales were $21.2 million. The company is optimistic that with the bioscan requirement removed, physicians, patients and payers will find Zevalin to be an exceedingly more attractive treatment option.
According to Spectrum Pharma, removal of the bioscan for Zevalin has a number of advantages as it eases the burden on patients, doctors, and the healthcare system.
* First and foremost, patients need to make one less trip to a Zevalin administration site and do not have to undergo a scan.
* Secondly, logistical coordination between the referring oncologist and the administering nuclear medicine or radiation oncology specialist is reduced.
* Third, it reduces the costs to the healthcare system of administering Zevalin by eliminating a costly scan.
As a part of broadening the utilization of Zevalin, the company plans to continue a pivotal study in diffuse large B-cell lymphoma and initiate additional Zevalin registrational studies vs. Rituximab in non-Hodgkin lymphoma.
The company has one more marketed oncology drug namely, Fusilev, indicated after high-dose methotrexate therapy in patients with osteosarcoma, and to diminish the toxicity and counteract the effects of impaired methotrexate elimination or inadvertent overdose of folic acid antagonists. In April of this year, the FDA approved the expanded indication of Fusilev for use in colorectal cancer.
Since its approval in 2008, sales of Fusilev have grown multi-fold, from nearly $8 million in 2008 to $32 million in 2010 and $109.6 million in the nine months ended September 30, 2011.
The other advanced drug candidates in the company's pipeline are Apaziquone for non-muscle invasive bladder cancer and Belinostat, which is being studied in multiple indications including a phase 2 registrational trial for relapsed or refractory peripheral T-cell lymphoma. The NDAs for Apaziquone and Belinostat are expected to be filed next year. The company also has a number of compounds in earlier stages of development in its portfolio.
A quick look at Spectrum Pharma's balance sheet...
In the third quarter ended September 30, 2011, the company earned $20.26 million or $0.34 per share, reversing a year-ago quarterly loss of $4.59 million or $0.09 per share. Total revenue, including product sales of Fusilev and Zevalin and licensing fees, rose to $51.02 million in the third quarter of 2011 from a mere $16.74 million in the year-ago comparable quarter.
The company ended the third quarter of 2011 with zero debt and cash of about $161 million.
Over the past year, shares of Spectrum Pharma have traded in a range of $4.42 to $12.88. The stock closed Friday's trading at $12.17 , down 1%.
For comments and feedback: editorial@rttnews.com