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In Small Test, Experimental Prostate Drug Shows Promise

Rating

3 Star

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In Small Test, Experimental Prostate Drug Shows Promise

Our Review Summary

Notwithstanding the headline, this is a story about two drugs for the treatment of advanced prostate cancer – Provenge, a drug recently approved by the FDA for the treatment of advanced prostate cancer and XL184, a compound currently under study.  Combining the information for these treatments is a bit confusing.  The news about XL184 reflected results which at that point had not yet been presented at a cancer conference in Berlin.  While indicating that it is too early to say whether XL184 actually affects the cancer, the story should have reminded readers of the importance of things like quality of life and survival time. And there isn’t evidence about those factors yet with XL184. At issue is that, while advanced prostate cancer is a challenge, not all men with advanced prostate cancer would benefit from Provenge, though the story neglected this.  And it is not clear that XL184 is of benefit to anyone.

 

Why This Matters

News about results from a small study that is still ongoing cannot carry enough caveats.  It is really too early to know whether XL184 really shows promise or not. It is bad enough when journalists write glowing stories based on reports from scientific meetings. This story goes one step beyond that and reports on the outcome of a small trial before the scientific meeting has even been held. Although there are numerous caveats embedded in the story, it still provides a rather optimistic view of a drug based on early testing in 20 men. For reasons that we don’t understand, the story only reports on 20 of the 99 men enrolled in the study and only reports on the more positive results (those related to bone scans). This selective reporting provides the readers with a very limited and imbalanced view of the study results.

Criteria

Does the story adequately discuss the costs of the intervention?

Satisfactory

The story provided the costs for the FDA approved Provenge ($93,000/patient); as XL184 is under study and not available for sale, there was no information about what its costs might be.

Does the story adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

The story included the numbers of men who were seen to have improvement in their bone scans.  While reporting on the improved bone scans seen in the men treated with XL184, the story did include some balance by indicating that this scan change might not translate into a change in the cancer in the bone and that nothing was yet known about how the drug affected longer term outcomes.

The increase in median longevity observed with Provenge was reported from one study, without including the insight from the two other larger scale studies.

In a split decision, we’ll give the story the benefit of the doubt on this criterion.

Does the story adequately explain/quantify the harms of the intervention?

Not Satisfactory

There was no mention of any possible harms associated with XL184 even though information available from the company indicates that fatigue, diarrhea, nausea, high blood pressure, rash, ‘hand-foot syndrome’, and cough have been seen in the small cohort of men treated with XL 184 for 6 weeks or more.

And while indicating that Provenge helped men with advanced prostate cancer live 4 months longer, there was no mention of any harms associated with use of this drug.

Does the story seem to grasp the quality of the evidence?

Not Satisfactory

This story provided no information other than positive findings of the study and the number of men treated.  There was no information about the study design, length of treatment, length of follow-up or adverse events that were reported.

The story did not do an adequate job detailing the level of information coming out of the ongoing study on XL184.  While reporting that 19 out of 20 patients experienced improvement in their bone scans, it only mentioned that ‘some’ patients were able to stop taking pain medications as after taking XL184.  Having a better looking bone scan is really not a meaningful endpoint for patients.

Although the story indicated that the results reported on were ‘very early results’ it should have explained what was meant by this statement.  XL184 is currently being studied in a shotgun trial where the investigational compound is being tried in patients with a variety (in this case 9) different solid tumors.  It is a phase II trial; and it is currently underway.

Does the story commit disease-mongering?

Satisfactory

The story did not engage in overt disease mongering.

Does the story use independent sources and identify conflicts of interest?

Satisfactory

The story quoted at least one clinical expert who did not appear to have ties to the study reported on or the company that makes the drug.
It would have greatly improved this story if insight from an expert on prostate cancer, especially castration-resistant prostate cancer had provided a context for evaluating the benefit of the drugs reported on – including quality of life issues.

Does the story compare the new approach with existing alternatives?

Not Satisfactory

The story did an inadequate job of explaining the target group of men who would be appropriate candidates to consider Provenge or for the study of XL184. And while mentioning that Taxotere, a drug currently used to treat advanced prostate cancer, has not been shown to have much affect on bone scans, the story could have seized the opportunity to explain that the benefits seen with Taxotere have not yet been demonstrated for XL184.  The story went on to add that drugs like Zometa and denosumab, used to treat bone lesions in men with advanced prostate cancer, haven’t been shown to fight cancer itself.  In fact – neither has XL184.  At this point – what we know is that after 6 weeks of treatment XL184 improves the picture seen on bone scan.  But we do not yet know whether it changes the course of the cancer itself – i.e. do men live longer?

Does the story establish the availability of the treatment/test/product/procedure?

Satisfactory

The story provided clear information about the availability of Provenge and XL184.

Does the story establish the true novelty of the approach?

Satisfactory

The story was clear about the novelty of the two drugs presented.

Does the story appear to rely solely or largely on a news release?

Not Applicable

We can’t be sure of the extent to which the story relied on a news release.  We know there was independent reporting because we know that several interviews were conducted.  But if the study results had yet to be presented and have not been published, where did the information come from? There was a company press release (http://www.exelixis.com/investors-media/press-releases ) and/or review of a poster before it was presented and/or there were advance interviews with researchers promoting their work.

Total Score: 5 of 9 Satisfactory

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