How was this diagnosed? There is no reliable test for men and HPV if you don't have actual warts present.
Type 61 is a low risk strain, meaning it's not associated with higher chances for cancers.
The IFN cream probably means that it's an interferon cream - though obviously I can't be sure about that without seeing it. Are you just supposed to rub it all over your penis 3 times a day for 8 weeks?
IFN creams - a very common one is called Aldara in the US, might be known as other things elsewhere - are usually used for spot treatment on visible warts.
Also, these are the instructions for Aldara:
"Aldara Cream should be applied 3 times per week to external genital/perianal warts. Aldara Cream treatment should continue until there is total clearance of the genital/perianal warts or for a maximum of 16 weeks." https://www.rxlist.com/aldara-drug.htm#dosage
If you decide to use it, please clarify that you understand the instructions, because 3 times a day is VERY different than 3 times a week.
The most common side effects of Aldara include:
minor skin pain, irritation, itching, redness, dryness, flaking, scabbing, crusting, scaling, swelling where the medicine was applied,
changes in the color of treated skin,
It is designed, essentially, to burn the warts off. If you have no warts, it will burn your skin.
I'm really very curious as to how you were diagnosed with this with no warts present.