Advantage Johnson & Johnson (J&J) could mean loss for Sun Pharma. The Mumbai-based drug maker might soon have to stop exporting its cancer drug, Lipodox, to the US, as J&J is preparing a comeback with Doxil.

Last December, J&J had to stop selling Doxil in the US market after health regulators found deficiencies in the production facility of the company's contract manufacturer, Ben Venue Laboratories.

This created an acute shortage of the drug, used in treatment of ovarian, bone marrow and AIDS-related skin cancer.

The Food and Drugs Administration (FDA), the US sector regulator, decided to import an alternative medicine - Lipodox - from Sun Pharma, even as the Indian company was yet to get an approval from it.

FDA, instead, exercised its enforcement discretion; it got into an agreement with Sun Pharma Global FZE, which manufactures the drug at an FDA-inspected facility in Halol, Gujarat.

FDA had said its exercise of enforcement discretion for Lipodox was temporary, a limited arrangement, specific to Sun Pharma Global FZE and its authorised distributor, Caraco Pharmaceutical Laboratories.

However, recently J&J indicated it had restored supplies of Doxil, putting an end to Sun Pharma's run in that market.

Since Sun is yet to get approval from the FDA for Lipodox, it is most likely it would have to pull back its supplies once J&J makes a comeback.

In a letter to health care providers in the US, Janssen Products, a J&J subsidiary, wrote, "All health care professionals can order Doxil through authorised distributors beginning October 22."

"Our supplies were to meet a specific shortage situation. We knew that we may no longer be required to supply if J&J returns to market and there is no shortage," a Sun Pharma spokesperson said in response to an email query from Business Standard.

The company did not mention getting a final approval from the US drug authorities. According to analyst estimates, Sun earned revenue of around $150 million from sales of Lipodox in the US. Sun would not share revenue figures on the drug.