Radius Health saw shares tank on Wednesday after reporting two Phase III study results, one for an osteoporosis patch treatment that failed and one for a breast cancer therapy showing lower efficacy results than expected.
The biotech is looking to develop a patch version of its injectable Tymlos drug for osteoporosis in postmenopausal women, but the treatment missed its primary endpoint and did not show non-inferiority relative to the approved injection. Radius is still angling to develop the treatment, but execs said in an investor call it would cause at least a two-year delay.
Meanwhile, Radius boasted of excellent Phase III results for the breast cancer therapy in October, but fuller results Wednesday showed the biotech underdelivered in investors’ eyes. While the treatment did reach statistical significance in the primary, reducing the risk of progression or death compared to standard of care by 30%, most of the benefit appeared to come from a specific mutation subgroup.
As a result, Radius shares $RDUS slid 44% in Wednesday’s trading session, wiping out nearly all the value gained off October’s breast cancer news.
Top biotech analyst Geoffrey Porges was all over the news, taking a slightly less fatalistic view than most in describing the data as ‘not such a shipwreck.’ Whereas the osteoporosis patch was previously likely to roll out in 2023, Porges now expects a 2025 debut at the earliest, making the treatment ‘salvageable.’
Porges placed an asterisk on the launch, however, as he also noted that in order to continue conducting clinical studies, Radius said it needs to enlist ‘non-traditional financing … without leaning on their balance sheet or issuing more equity.’ It will probably take until the middle of next year before Radius cements its path forward here, he added.
For the breast cancer drug, known as elacestrant, Jefferies analyst Eun Yang described the fuller dataset as ‘surprisingly modest’ and highlighted a much higher efficacy for patients with ESR1-mutations, accounting for 47% of the population. Though the candidate hit the primary endpoint, Yang estimated a median PFS of only 1.9 months in non-mutant patients, which is similar to standard of care.
That could limit the approval to only the relevant subgroup, Yang wrote to investors, severely dampening the drug’s potential sales.
The full data were as follows: the osteoporosis patch demonstrated a 7.1% increase compared to baseline in lumbar spine bone mineral density after a year, compared to 10.8% in the volunteers who received the injectable form of Tymlos. The patch also missed non-inferiority on secondary endpoints looking at head and femoral neck bone density, hitting 2.0% and 1.9% increases compared to 3.7% and 3.4%, respectively.
In the elacestrant trial, the drug reduced risk of progression or death by 30% compared to SoC in the overall population and by 45% in the ESR1-mutated subgroup. The p-values came in at p=0.0018 and p=0.0005 for each. Radius said the median PFS was extended by 2.79 months in the whole study, compared to 1.91 months for standard of care. .
Tymlos was Radius’ first-ever drug approval, getting an FDA nod back in 2017 and going up against heavyweights in J&J and Amgen. Elacestrant’s global commercial rights were acquired by the Menarini Group in 2020 for $30 million, and Menarini is on the hook for $320 million in milestones and royalties in the low to mid-teens.
https://endpts.com/radius-falters-after-a-phiii-osteoporosis-fail-and-another-breast-cancer-disappointment-sending-shares-plummeting/
