This news release describes a phase 1 safety trial of a new cancer therapy undergoing testing for certain pediatric cancers. Rather than focusing on the safety and tolerability of the study — which is the purpose of a phase 1 trial — the news release takes a great leap by claiming success in treating patients, and in particular one patient who apparently had a positive tumor response — even though that was not the primary purpose of the trial.
The release needed to add some cautionary language that the drug is still in the early phases of testing, otherwise it could leave young patients and family members with false hopes. Overcoming a hurdle of bringing a potential new drug to market is worth announcing, but sponsors must take care not to mislead the public about how many hurdles remain.
The primary focus of this phase 1 trial was to demonstrate that the drug is safe and tolerable among pediatric patients. Instead of highlighting this finding, the news release emphasized that 93% of the patients achieved a response rate without explaining that this was a secondary endpoint observed among 15 patients. It went into further detail describing the dramatic improvement among one of the trial participants. Hopefully, these outcomes will be demonstrated in a wide number of patients over the course of further investigation. But this requires much larger sample sizes and follow-up time periods.
There are three big benefits to following the story of larotrectinib over time. The first is that pediatric populations have historically suffered from less extensive pharmaceutical testing. This patient population is inherently more vulnerable, and the ethical and pharmacology considerations are more complex. This leads to more innovative trial designs like the one used in this phase 1 trial to shorten trial timelines. The second key benefit is that targeted, tolerable drug therapy may be much more desirable than the existing treatment alternatives, which include disfiguring surgical therapies or highly toxic chemotherapy regimens. Lastly, because this drug targets a gene that is not currently widely tested for, we may anticipate spin-off innovation to accelerate and facilitate genetic testing. These emerging treatment approaches will lead to discussions about how we pay for expensive drugs and genetic tests in our current payment structure, which is compounded by the fact that the targeted patient population is expected to be very small compared to the general population.
The release doesn’t offer any cost projections.
Although larotrectinib is not yet FDA approved and therefore not available for sale in the US, its ultimate approval seems likely. In fact, the company that makes larotrectinib, Loxo Oncology, has pursued a partnership agreement with Bayer Pharmaceuticals to market the new drug in the US.
Gene-targeted oncology drugs that have already hit the market, some of which are now available in generic form, have remained very expensive therapeutic options. An added expense with larotrectinib is that genetic testing for the oncogenic mutations NTK1, NTK2, and NTK3 is not yet commonplace. All of these factors suggest that larotrectinib will be an expensive treatment.
The primary endpoint of the phase 1 study was safety and tolerability of the drug among a small number (17) of pediatric patients with and without specific genetic mutations. These results are essential to demonstrate before larger trials to demonstrate clinical effectiveness can commence.
The release presented the anecdotal story of one patient’s tumor response and claimed a “93 percent tumor response rate” in the headline. With so few patients, this is just a rough estimate and very misleading.
In addition, the release reports that the “response was long-lasting for most patients” without clarifying that the median follow-up period for the trial was just 8.2 months.
The news release does not mention any of the specific harms from the drug.
This phase 1 safety trial demonstrated only that the drug is sufficiently safe to take to the next level of trials, not to use in practice.
The release mentions that “none of the patients with TRK fusions had to quit the study because of a drug-induced side effect.” This is a key finding of the study and readers would have benefited from a more thorough explanation of the harms. There were seven patients enrolled without the genetic mutation. Four patients experienced a grade 3 (severe) adverse event. No patients experienced a grade 4 or 5 adverse (life threatening) event. These are important results of the study because they support future testing of the drug in larger pediatric populations.
The lack of evidence is a major weakness of the news release. It sensationalizes a secondary outcome (tumor shrinkage) and ignores the reason the study was done in the first place (to assess safety and tolerability in a small number of patients).
The drug has a lot of testing to undergo involving larger groups of volunteers for a longer period of time before it can be approved as a treatment for pediatric cancer patients.
The news release does not describe the study design of the phase 1 trial. It does not characterize it as a small safety trial, and it emphasizes the impressive results of one of the participants without qualifying that these results may not be generalizable to larger populations when the drug is tested in clinical effectiveness trials.
The release doesn’t engage in disease-mongering. It notes that the NTRK mutations exist in rare pediatric cancers without exaggerating the severity of the underlying disease.
The release lists the funders of the trial and notes that the lead investigator is a paid consultant for Loxo Oncology.
The case study of the responsive patient includes mention of surgical management of her tumor prior to larotrectinib. The release does not include mention of the chemotherapy agents that are considered first-line therapy for many pediatric cancers.
The release does not make it clear that the drug is not yet available in the US beyond clinical trials.
The company recently completed its application for fast track approval from the FDA but it is not yet approved.
The release makes at least two claims of novelty, calling the drug “A first-of-its-kind drug targeting a fused gene,” and also that “Larotrectinib is the first cancer drug to receive FDA breakthrough therapy designation for patients with a specific fusion of two genes in the cancer cell, no matter what cancer type.”
An emerging cancer drug for a cancer with limited treatment options is an important health update.
This release emphasizes the possibility of a very helpful new cancer drug, but it’s irresponsible to refer to results from a phase 1 safety trial as having an “unprecedented” response and “amazing.” It’s misleading to trumpet effectiveness on a very small sample that was not intended to evaluate effectiveness. It’s still too early to say the treatment works.