Wall Street analysts keeping a close watch on the development of Genomic Health's multi-gene expression prostate cancer diagnostic expressed cautious optimism upon seeing top-line data from a validation study the company will present at an upcoming medical conference.
Genomic Health's Oncotype DX prostate cancer test is slated for launch later this year and represents a major commercial opportunity for the company. The test is being developed by Genomic Health as a tool that doctors can use in conjunction with the Gleason grading system, the prostate specific antigen test, and patients' other clinical data to personalize prostate cancer treatment. The molecular diagnostic, according to Genomic Health, can differentiate which patients have aggressive or indolent disease.
Matthew Cooperberg, assistant professor of urology, epidemiology and biostatistics at the University of California, San Francisco, will present data from the first Oncotype DX prostate cancer validation study on May 8 at the American Urological Association's annual meeting in San Diego. During this presentation, Cooperberg will also discuss results from six feasibility and development studies previously conducted in partnership with the Cleveland Clinic, in which investigators looked at 700 patients and evaluated 700 candidate genes to hone in on the gene expression panel for the prostate cancer test.
"Based on these new findings, Genomic Health is completing the necessary work to make the Oncotype DX Genomic Prostate Score available to physicians and patients by the end of the second quarter of 2013," the company said in a statement. According to the embargo policies of the AUA annual meeting, members of the press cannot report on abstract data until they are presented at the meeting.
In a note to investors, Vamil Divan, an analyst with investment bank Credit Suisse, expressed "incremental enthusiasm" after reviewing the abstract data on the Oncotype DX prostate cancer test. "First, and most important, the clinical validation study showed that the Genomic Prostate Score (GPS) was a strong and statistically significant predictor of high grade and/or pT3 disease," Divan wrote in his note. "Second, the validation study successfully used [formalin-fixed prostate] tissue that was obtained from a single prostate needle biopsy." One of the advantages that Genomic Health has highlighted about its RT-PCR test is that it requires "very small amounts" of tissue.
Third, Divan highlighted as a positive that the sizes of the development and validation studies were "relatively large," involving several hundred patient samples.
Investors will pay close attention to any data coming out of the May 8 presentation on Genomic Health's test that could help differentiate it from Myriad Genetics' Prolaris test, which will likely be the main competitor to the Oncotype DX test. "Considering the overtreatment that currently exists in prostate cancer, a test that can convince at least 15 percent to 20 percent of patients to forgo unnecessary treatment would likely be considered a significant clinical advance," Divan said in his note to investors.
According to an NIH estimate, in 2010, the annual medical costs associated with prostate cancer in the US were $12 billion. Molecular diagnostics being developed by Genomic Health and Myriad are hoping to reduce the costs associated with unnecessary treatment in those at low risk of prostate cancer recurrence.
Myriad's Prolaris analyzes the expression level of 46 cell cycle progression genes and stratifies men's risk of biochemical recurrence of prostate cancer. Researchers from UCSF and Myriad recently published the fourth validation study involving Prolaris in the Journal of Clinical Oncology, which analyzed samples from 400 men who had undergone a radical prostatectomy. In the published study, researchers reported that 100 percent of the men whom Prolaris deemed to be at "low risk" of recurrence did not experience a recurrence within the five years the study was ongoing. Meanwhile, 50 percent of those the test deemed to be a "high risk" did experience recurrence during that time (PGx Reporter 3/6/2013).
Additionally, the researchers found that the Prolaris test could "more accurately predict the risk of prostate cancer recurrence than current clinical parameters used in risk assessment."
Myriad has estimated that its prostate cancer diagnostic has a $1 billion market potential. Similar to the Oncotype DX prostate cancer test, the company is marketing Prolaris as a test that doctors can use in conjunction with clinical parameters to gauge the aggressiveness of a patients' prostate cancer. Including this fourth validation study, Myriad has said that it has published peer-reviewed data on Prolaris involving 1,500 patients.
Meanwhile, Canadian firm GenomeDx is planning to launch a prostate cancer molecular diagnostic later this year, called Decipher. The company recently presented data at a medical conference on the test's clinical validity and utility in predicting which patients are at risk of recurrence and metastasis after prostate cancer surgery. The company has said it has 22 studies underway with the Decipher test involving 4,000 patients (PGx Reporter 2/20/2013).
With around 240,000 men diagnosed with prostate cancer annually, Genomic Health officials have presented the Oncotype DX prostate cancer test as the "largest opportunity to date" for the company. In anticipation of the test's launch later this year, Genomic Health has hired a national sales director and senior director of urology medical affairs to help drive test adoption by physicians and reimbursement among payors.
Beyond this initial clinical validation trial, Genomic Health has said it will need to conduct several clinical studies in order capture the full market opportunity from the prostate cancer launch, drive broad adoption of the test, and garner reimbursement nationwide. The company has also said it is developing educational websites through which patients can learn more about the Oncotype DX prostate cancer test.