New Delhi: Amid safety concerns, the Indian drug regulator has warned against the use of some of Abbott India Ltd’s bioresorbable stents, which dissolve in the body after the blood flow to blocked arteries is restored.

The warning, part of a report by an expert panel formed to study such stents, pertains to stents used in blood vessels that are 2.5mm or narrower. For larger vessels, the regulator has said that the bioresorbable stents may be used, but only in controlled settings.

The stents, made by Abbott’s vascular division, are absorbed by the body roughly over three years.

The Drug Controller General of India (DCGI) has also pressed Abbott to conduct phase IV clinical trials on its vascular stent in India.

A decision on the fate of these stents will now be taken by an expert committee on cardiovascular devices next month. US-based Abbott has been operating in the country since 1910.

In April, the committee reviewed safety data on the devices, and asked Abbott to conduct a systematic follow-up of each patient implanted with the vascular stents. It also asked the company to outline a future course of action, which includes the company maintaining records of post-surveillance data on all cases where the bioresorbable stents are used and submit a plan for conducting phase IV trials on the vascular stent.

According to a senior government official who spoke on condition of anonymity, the company has submitted a future plan of action, but not the phase IV trial protocol.

“They have been insisting that their product is safe and hence there was no need to conduct trials. The matter has been referred to the subject expert committee, which will decide on its future," added the official.

An Abbott spokesperson said in an email response to queries that it was engaging with the Central Drugs Standard Control Organization (CDSCO) “on an ongoing basis" and submitted a plan to address the request to clinically follow patients who receive the Absorb dissolving stent. “A CDSCO medical device alert of 7 April does not restrict the use of Absorb in India. We have submitted the updated IFU (instructions for use) with respect to the change in the vessel diameter for DCGI’s approval," the spokesperson added.

The bioresorbable stents came under the scanner after red flags were raised on the device by drug regulators in the US, Europe and Australia following the results of two big research trials.

India’s drug regulator then issued an advisory asking patients and medical professionals to report any adverse events to CDSCO or to Abbott in the US and Maharashtra.

“Absorb BVS (bioresorbable vascular scaffold) was in the news recently for all the wrong reasons. After the dismal results of Absorb III trial, a number of countries have recalled this BVS from their market," said Nishith Chandra, director, interventional cardiology, Fortis Escorts Heart Institute.

“The decision to undertake this recall and remove Absorb BVS System was based on data from recent analyses that showed an elevated rate of major adverse cardiac events, specifically heart attack and blood clot, when compared to patients treated with a metallic stent," Chandra said.