Producing solid 12-month data had been billed as the big test for Ariad Pharmaceuticals' (ARIA) ponatinib in drug-resistant leukaemia, and last week at As,h the project passed with flying colors. While many had expected it to do well, the data will be a welcome boost for ponatinib's chances of passing muster at the FDA for its PDUFA decision, due by March 27.
More importantly, the results should give Ariad encouragement that a first-line setting is achievable. The drug is being studied in this patient population, but results are not expected until the middle of 2014, and must show significant benefit over the incumbent, Gleevec, if ponatinib is to achieve some of the lofty sales figures being put against it.
Longer And Stronger
The 12-month follow-up data from the Pace trial showed that the earlier impressive 10-month results had been maintained, with 56% of chronic-phase CML patients achieving a major cytogenic response, or nearly clearing the disease from their bone marrow. The results were in fact even better than the 10-month data, where 54% of patients had shown a MCyR.
The complete cytogenetic response rate was 46% versus the 44% reported at Asco, and patients with more aggressive form of the disease also showed sustained benefits on ponatinib.
The high level of response should play well with regulators, who approved Pfizer’s Bosulif on a 27% MCyR. Ponatinib also worked well across variations of the disease, as 70% of patients with a T35I mutation also achieved a MCyR.
Moving Up The Line
But what Ariad is almost certain to be concentrating on is the project's performance in patients who had only previously received one round of treatment with a tyrosine kinase inhibitor. Of the 19 patients who qualified, 84% achieved a MCyR, strengthening the case for earlier use of the drug.
If approved, ponatinib would be positioned as a third-line therapy behind Sprycel and Tasigna, which are used after patients have failed on Gleevec. Ariad’s Epic trial, which is designed to move it up the treatment pecking order, started recruited patients for first-line use in July, but is not expected to yield results until the middle of 2014.
However, given ponatinib’s performance, doctors might decide to introduce it into the treatment cycle earlier if and when it is approved. The only fly in the ointment for ponatinib could be side effects, which include pancreatitis.
Thankfully for Ariad, the incidence of pancreatitis did not increase over 12 months, but other adverse events did over the longer treatment period. More worryingly, new adverse events, including hypertension and fever, were reported.
While analysts believe that these events are easily managed, the fact that they occurred with longer use of ponatinib might ring alarm bells.
But with the 12-month follow-up data out the way, Ariad will focus on its next big catalyst – approval in the third-line setting. Analysts certainly think that this is in the bag, as sales predictions for the drug have been rising steadily.
According to data from EvaluatePharma, forecasts for sales in 2016 have jumped by $280m to $653m in less than a year. And by 2018, the drug is expected to have reached blockbuster status, with revenues of $1.23bn.
But all of this depends on Ariad not being interrupted in its journey towards first-line use, a path along which it has taken a significant step with the 12-month Pace data.