The U.S. Food and Drug Administration (FDA) has postponed for up to three months its decision on pano­bino­stat’s new drug application.

The FDA action was announced earlier this morning in a press release ^[1] issued by Novartis (NYSE:NVS), the Swiss pharmaceutical company developing pano­bino­stat ^[2] as a potential new multiple myeloma therapy.

A decision on pano­bino­stat’s application for FDA approval had been expected by the end of this week. The decision was widely anticipated to be a negative one, given that earlier this month the FDA’s Oncologic Drugs Advisory Committee (ODAC) voted 5-2 against recommending pano­bino­stat for approval (see related Beacon ^[3] news).

Today’s news that the FDA has extended its review of pano­bino­stat ^[4] is a sign the drug’s chances of approval are higher than many had assumed after the ODAC meeting and vote.

During the ODAC meeting, FDA staff and advisory com­mit­tee members repeatedly expressed concern about pano­bino­stat’s safety and raised questions about the reliability of the drug’s efficacy data.

Novartis employees and several myeloma experts sought to address these questions and concerns. How­ever, a sufficient number of issues remained open by the end of the meeting that a majority of the com­mit­tee did not feel comfortable recommending pano­bino­stat for approval.

The FDA decision to extend the time for its review of pano­bino­stat suggests that it may be interpreting ODAC’s vote as something other than a definitive “do not approve this drug” statement.

Many would say this is a reasonable interpretation of where the com­mit­tee was at the end of its meeting, with its vote being driven – at least in part – more by a sense of uncertainty, and less by a sense that pano­bino­stat is either clearly unsafe, clearly ineffective, or both.

Going forward, the FDA continues to have the same options available to it in regard to its decision on pano­bino­stat's approval application.

It can choose to approve the drug as Novartis has requested. In that case, panobinostat would be approved for use in combination with Velcade ^[5] (bortezomib) and dexamethasone ^[6] (Decadron) to treat multiple myeloma patients who have had at least one prior therapy.

It can choose to develop, together with Novartis, a more restrictive approved use of pano­bino­stat.  This could involve, for example, stricter patient eligibility for treatment with the drug, or more extensive monitoring requirements. This option may be difficult to accomplish, however, in the three months the FDA has given itself for its review.

Finally, the agency could issue Novartis what is known as a “complete response letter.” This document would explain to Novartis why the FDA currently is unwilling to approve pano­bino­stat, and what steps could be taken to allow the agency to once again consider the drug for approval.  Those steps could involve a new trial of the drug, or simply additional data or data analyses from ongoing pano­bino­stat trials.

Which of these options is the FDA most likely to pursue? At this point, it is very difficult for anyone not directly involved in the panobinostat review process to answer that question. The agency knows what its concerns are, and Novartis is responsible for seeking to address those concerns.

Everyone else will have to wait until the end of next February – the new deadline for the FDA's decision on panobinostat's approval application – to see how the matter is resolved.